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[[Image:Splash-prop.jpg|right|720px]]<strong><font color="#4e1985" size="4">True 3D, Coherent, Polarimetric Ray Tracer That Simulates Very Large Urban Scenes In Just Few Minutes!</font></strong><table><tr><td>[[image:Cube-icon.png | link=Getting_Started_with_EM.Cube]] [[image:cad- Taking out this picture for now for consistencyico.png | link=Building_Geometrical_Constructions_in_CubeCAD]] [[Fileimage:urbanfdtd-ico.png| link=EM.Tempo]][[image:static-ico.png | link=EM.Ferma]] [[image:planar->ico.png | link=EM.Terrano is a physicsPicasso]] [[image:metal-based, siteico.png | link=EM.Libera]] [[image:po-specific, wave propagation modeling tool that enables engineers to quickly determine how radio waves propagate in urban, natural or mixed environmentsico. The rapid growth of wireless communications along with the high costs associated with the design and deployment of effective wireless infrastructures underline a persistent need for computer aided communication network planning toolspng | link=EM. Wireless engineers have long used simplistic statistical prediction models based on measurements that often exhibit considerable errors especially in areas having mixed building sizesIllumina]]</td><tr></table>[[Image:Tutorial_icon.png|30px]] '''[[EM.Cube#EM.Terrano_Documentation | EM.Terrano Tutorial Gateway]]'''

Since its introduction in 2002, EM.Terrano has helped wireless engineers around the globe model the physical channel and the mechanisms by which radio signals propagate from transmitters to receivers[[Image:Back_icon. png|30px]] '''[[EM.Terrano’s advanced ray tracing simulator finds the dominant propagation paths specific Cube | Back to the site in question. It calculates the true signal characteristics at the actual locations using physical databases of the buildings and terrain at a given site, not those of a statistically average or representative environment. EM.Terrano’s ray tracer is based on the shoot-and-bounce-rays (SBR) method, which utilizes geometrical optics (GO) in combination with uniform theory of diffraction (UTD) models of building edges.Cube Main Page]]'''==Product Overview==

The new ===EM.Terrano 2013 has been totally reconstructed based on our integrated [[EM.Cube]] software foundation. This integration has created the opportunity to inject a host of new powerful features such as a highly customizable terrain generator, DEM terrain import, complex building constructions, and versatile interior wall arrangements for indoor propagation modeling. As a result of this seamless interface with [[EM.Cube]]'s other modules, you can now model complex antenna systems in [[EM.Picasso]], [[EM.Tempo]] or [[EM.Libera]], and generate antenna radiation patterns than can be used to model directional transmitters and receivers at the two ends of your propagation channel. Conversely, you can analyze a propagation scene in EM.Terrano and import the rays received at a certain receiver location as coherent plane wave sources to [[EM.Picasso]], [[EM.Tempo]] or [[EM.Libera]]. You can also model periodic wall or ground structures using the periodic simulation capability of [[EM.Picasso]] or [[EM.Tempo]] and generate macromodels for their reflection and transmission coefficients as functions of the ray incidence angles. You can then define buildings or terrains in your propagation scene that are governed by such macromodels.Nutshell ===

== An EM.Terrano Primer ==is a physics-based, site-specific, wave propagation modeling tool that enables engineers to quickly determine how radio waves propagate in urban, natural or mixed environments. EM.Terrano's simulation engine is equipped with a fully polarimetric, coherent 3D ray tracing solver based on the Shooting-and-Bouncing-Rays (SBR) method, which utilizes geometrical optics (GO) in combination with uniform theory of diffraction (UTD) models of building edges. EM.Terrano lets you analyze and resolve all the rays transmitted from one ore more signal sources, which propagate in a real physical channel made up of buildings, terrain and other obstructing structures. EM.Terrano finds all the rays received by a receiver at a particular location in the physical site and computes their vectorial field and power levels, time delays, angles of arrival and departure, etc. Using EM.Terrano you can examine the connectivity of a communication link between any two points in a real specific propagation site.

=== Modeling Since its introduction in 2002, EM.Terrano has helped wireless engineers around the Wireless Propagation Channel===globe model the physical channel and the mechanisms by which radio signals propagate in various environments. EM.Terrano’s advanced ray tracing simulator finds the dominant propagation paths at each specific physical site. It calculates the true signal characteristics at the actual locations using physical databases of the buildings and terrain at a given site, not those of a statistically average or representative environment. The earlier versions of EM.Terrano's SBR solver relied on certain assumptions and approximations such as the vertical plane launch (VPL) method or 2.5D analysis of urban canyons with prismatic buildings using two separate vertical and horizontal polarizations. In 2014, we introduced a new fully 3D polarimetric SBR solver that accurately traces all the three X, Y and Z components of the electric fields (both amplitude and phase) at every point inside the computational domain. Using a 3D CAD modeler, you can now set up any number of buildings with arbitrary geometries, no longer limited to vertical prismatic shapes. Versatile interior wall arrangements allow indoor propagation modeling inside complex building configurations. The most significant recent development is a multicore parallelized SBR simulation engine that takes advantage of ultrafast k-d tree algorithms borrowed from the field of computer graphics and video gaming to achieve the ultimate speed and efficiency in geometrical optics ray tracing.

The rapid growth of wireless communications along with [[Image:Info_icon.png|30px]] Click here to learn more about the high costs associated with the design and deployment '''[[Basic Principles of effective wireless infrastructures underline a persistent need for computer aided communication network planning tools. Wireless engineers have long used simplistic statistical prediction models based on measurements that often exhibit considerable errors especially in areas having mixed building sizesSBR Ray Tracing | Basic SBR Theory]]'''.

Every wireless communication system involves a transmitter that transmits some sort of signal (voice, video, data, etc<table><tr><td> [[Image:Manhattan1.), a receiver that receives and detects the transmitted signal, and a channel in which the signal is transmitted into the air and travels from the location of the transmitter to the location of the receiver. The channel is the physical medium in which the electromagnetic waves propagate. The successful design of a communication system depends on an accurate link budget analysis that determines whether the receiver receives adequate signal power to detect it against the background noise. The simplest channel is the free space. Real communication channels, however, are more complicated and involve a png|thumb|left|420px|A large number of wave scatterers. For example, in an urban environment, the obstructing buildings, vehicles and vegetation reflect, diffract or attenuate the propagating radio waves. As a result, the receiver receives a distorted signal that contains several components with different power levels and different time delays arriving from different anglespropagation scene featuring lower Manhattan.]]</td></tr></table>

The different rays arriving at a receiver location create constructive and destructive interference patterns=== EM. This is known Terrano as the multipath effect. This together with the shadowing effects caused by building obstructions lead to channel fading. In many wireless applications, the total received power by the receiver is all that matters. In some others, the angle of arrival of the rays as well as their polarization are Propagation Module of immense interestEM. Cube ===

==EM.Terrano in is the ray tracing '''Propagation Module''' of '''[[EM.Cube]]''', a Nutshell ==comprehensive, integrated, modular electromagnetic modeling environment. EM.Terrano shares the visual interface, 3D parametric CAD modeler, data visualization tools, and many more utilities and features collectively known as [[Building_Geometrical_Constructions_in_CubeCAD | CubeCAD]] with all of [[EM.Cube]]'s other computational modules.

With the seamless integration of EM.Terrano is a physics-basedwith [[EM.Cube]]'s other modules, site-specific, wave propagation modeling tool that enables engineers to quickly determine how radio waves propagate you can now model complex antenna systems in urban[[EM.Tempo]], natural or mixed environments. [[EM.Terrano's simulation engine is equipped with a fully polarimetricLibera]], coherent ray tracing solver based on the Shooting-and-Bouncing-Rays (SBR) method[[EM. Picasso]] or [[EM.Terrano lets you analyze Illumina]], and resolve all generate antenna radiation patterns that can be used to model directional transmitters and receivers at the rays transmitted from one ore more signal sources, which propagate in a real physical site made up two ends of buildings, terrain and other obstructing structuresyour propagation channel. Conversely, you can analyze a propagation scene in EM.Terrano finds , collect all the rays received by at a certain receiver at a particular location in the physical site and computes their power levelsimport them as coherent plane wave sources to [[EM.Tempo]], time delays[[EM.Libera]], angles of arrival, etc[[EM.Picasso]] or [[EM.Illumina]].

=== Line-of-Sight vs[[Image:Info_icon.png|30px]] Click here to learn more about '''[[Getting_Started_with_EM.Cube | EM.Cube Modeling Environment]]'''. Multipath Propagation Channel ===

In a free-space line-=== Advantages & Limitations of-sight (LOS) communication system, the signal propagates directly from the transmitter to the receiver without encountering any obstacles (scatterers). Free-space line-of-sight channels are ideal scenarios that can typically be used to model aerial or space communication system applicationsEM.Terrano's SBR Solver ===

Click here to learn more about EM.Terrano's SBR simulation engine utilizes an intelligent ray tracing algorithm that is based on the theory concept of k-dimensional trees. A k-d tree is a [[Freespace-partitioning data structure for organizing points in a k-dimensional space. k-d trees are particularly useful for searches that involve multidimensional search keys such as range searches and nearest neighbor searches. In a typical large radio propagation scene, there might be a large number of rays emanating from the transmitter that may never hit any obstacles. For example, upward-looking rays in an urban propagation scene quickly exit the computational domain. Rays that hit obstacles on their path, on the other hand, generate new reflected and transmitted rays. The k-d tree algorithm traces all these rays systematically in a very fast and efficient manner. Another major advantage of k-d trees is the fast processing of multi-Space Propagation Channel]]transmitters scenes.

[[Image:multi1_tnEM.png|thumb|400px|A multipath propagation scene showing Terrano performs fully polarimetric and coherent SBR simulations with arbitrary transmitter antenna patterns. Its SBR simulation engine is a true asymptotic &quot;field&quot; solver. The amplitudes and phases of all the rays arriving at a particular receiver.]]In ground-based systemsthree vectorial field components are computed, analyzed and preserved throughout the presence of entire ray tracing process from the ground as a very large reflecting surface affects the signal propagation source location to a large extentthe field observation points. Along You can visualize the path from a transmitter to a receiver, magnitude and phase of all six electric and magnetic field components at any point in the signal may also encounter many obstacles and scatterers such as buildings, vegetation, etccomputational domain. In an urban canyon environment with many most scenes, the buildings of different heights and other scatterers, a line of sight between the transmitter and receiver ground or terrain can hardly be establishedassumed to be made of homogeneous materials. These are represented by their electrical properties such as permittivity &epsilon;_r and electric conductivity &sigma;. More complex scenes may involve a multilayer ground or multilayer building walls. In such cases, one can no longer use the propagating signals bounce back and forth among the building surfaces. It is these reflected simple reflection or diffracted signals that are often received and detected by the receivertransmission coefficient formulas for homogeneous medium interfaces. Such environments are referred to as “multipath”EM. The group Terrano calculates the reflection and transmission coefficients of rays arriving at a specific receiver location experience different attenuations multilayer structures as functions of incident angle, frequency and different time delays. This gives rise to constructive polarization and destructive interference patterns that cause fast fading. As a receiver moves locally, uses them at the receiver power level fluctuates sizably due to these fading effectsrespective specular points.

The use It is very important to keep in mind that SBR is an asymptotic electromagnetic analysis technique that is based on Geometrical Optics (GO) and the Uniform Theory of statistical models for prediction of fading effects Diffraction (UTD). It is widely popular not a &quot;full-wave&quot; technique, and it does not provide a direct numerical solution of Maxwell's equations. SBR makes a number of assumptions, chief among communication system designersthem, a very high operational frequency such that the length scales involved are much larger than the operating wavelength. These models Under this assumed regime, electromagnetic waves start to behave like optical rays. Virtually all the calculations in SBR are either based on measurement data or derived far field approximations. In order to maintain a high computational speed for urban propagation problems, EM.Terrano ignores double diffractions. Diffractions from simplistic analytical frameworksedges give rise to a large number of new secondary rays. The statistical models often exhibit considerable errors especially in areas having mixed building sizespower of diffracted rays drops much faster than reflected rays. In such casesother words, one needs to perform a physicsan edge-baseddiffracted ray does not diffract again from another edge in EM.Terrano. However, site-specific analysis of the propagation environment to accurately identify reflected and establish all the possible signal paths penetrated rays do get diffracted from edges just as rays emanated directly from the transmitter to the receiver. This involves an electromagnetic analysis of the scene with all of its geometrical and physical detailssources do.

Link budget analysis for a <table><tr><td> [[Image:Multipath_Rays.png|thumb|left|500px|A multipath channel is a challenging task due to the large size of the computational domains involved. Typical urban propagation scenes usually involve length scales on scene showing all the order of thousands of wavelengths. To calculate the path loss between the transmitter and rays collected by a receiver, one must solve Maxwell's equations in an extremely large space. Full-wave numerical techniques like the Finite Difference Time Domain (FDTD) method, which require a fine discretization of the computational domain, are therefore impractical for solving large-scale propagation problems. The practical solution is to use asymptotic techniques such as SBR, which utilize analytical techniques over large distances rather than a brute force discretization of the entire computational domain. Such asymptotic techniques, of course, have to compromise modeling accuracy for practical computation feasibility.]]</td></tr></table>

=== The SBR Method Scene Definition / Construction ===

[[EM.Cube]]'s [[Propagation Module]] provides an asymptotic ray tracing simulation engine that is based on a technique known as Shooting-<ul> <li> Buildings/blocks with arbitrary geometries and-Bouncing-Rays (SBR). In this technique, propagating spherical waves are modeled as ray tubes material properties</li> <li> Buildings/blocks with impenetrable surfaces or beams that emanate from a sourcepenetrable surfaces using thin wall approximation</li> <li> Multilayer walls for indoor propagation scenes</li> <li> Penetrable volume blocks with arbitrary geometries and material properties</li> <li> Import of shapefiles and STEP, travel in space, bounce from obstacles IGES and are collected by the receiver. As rays propagate away from their source STL CAD model files for scene construction</li> <li> Terrain surfaces with arbitrary geometries and material properties and random rough surface profiles</li> <li> Import of digital elevation map (transmitterDEM)terrain models</li> <li> Python-based random city wizard with randomized building locations, they begin to spread (extents and orientations</li> <li> Python-based wizards for generation of parameterized multi-story office buildings and several terrain scene types</li> <li> Standard half-wave dipole transmitters and receivers oriented along the principal axes</li> <li> Short Hertzian dipole sources with arbitrary orientation</li> <li> Isotropic receivers or diverge) over distance. In receiver grids for wireless coverage modeling</li> <li> Radiator sets with 3D directional antenna patterns (imported from other words, the cross section modules or footprint external files)</li> <li> Full three-axis rotation of a ray tube expands as a function of the distance from the source. [[EM.Cube]] uses an accurate equiimported antenna patterns</li> <li> Interchangeable radiator-angular ray generation scheme to that produces almost identical ray tubes in all directions to satisfy energy based definition of transmitters and power conservation requirements.receivers (networks of transceivers)</li></ul>

# Reflection <ul> <li> Fully 3D polarimetric and coherent Shoot-and-Bounce-Rays (SBR) simulation engine</li> <li> GTD/UTD diffraction models for diffraction from the locally flat building edges and terrain</li> <li> Triangular surfacemesh generator for discretization of arbitrary block geometries</li># Transmission <li> Super-fast geometrical/optical ray tracing using advanced k-d tree algorithms</li> <li> Intelligent ray tracing with user defined angular extents and resolution</li> <li> Ray reflection, edge diffraction and ray transmission through multilayer walls and material volumes</li> <li> Communication link analysis for superheterodyne transmitters and receivers</li> <li> 17 digital modulation waveforms for the locally flat surfacecalculation of E_b/N₀ and Bit error rate (BER)</li># Diffraction from <li> Incredibly fast frequency sweeps of the entire propagation scene in a single SBR simulation run</li> <li> Parametric sweeps of scene elements like building properties, or radiator heights and rotation angles</li> <li> Statistical analysis of the propagation scene</li> <li> Polarimetric channel characterization for MIMO analysis</li> <li> "Almost real-time" Polarimatrix solver using an edge existing ray database</li> <li> "Almost real-time" transmitter sweep using the Polarimatrix solver</li> <li> "Almost real-time" rotational sweep for modeling beam steering using the Polarimatrix solver</li> <li> "Almost real-time" mobile sweep for modeling mobile communications between two conjoined locally flat surfacesTx-Rx pairs along a mobile path using the Polarimatrix solver</li></ul>

[[EM.Cube]] discretizes all the objects of the scene into flat triangular facets. Obviously, rectangular and cubic objects preserve their geometric shapes through this discretization. Objects with curved surfaces such as cylinders, cones or spheres, are approximated by === Data Generation &quotamp;polymesh&quot; representations. The geometric fidelity of the resulting mesh depends on the specified mesh edge length. When a ray hits a triangular facet, the propagating spherical wave is approximated as a plane wave at the specular point. The reflection and transmission coefficients of the surface are calculated at the operational frequency and at the particular ray incident angle. Visualization ===

A new reflected ray is generated at the specular point<ul> <li> Standard output parameters for received power, path loss, SNR, which starts traveling E_b/N₀ and bouncing around BER at each individual receiver</li> <li> Graphical visualization of propagating rays in the scene. If the obstructing surface is penetrable, a second transmitted ray is generated </li> <li> Received power coverage maps</li> <li> Link connectivity maps (based on minimum required SNR and added to the scene. If the BER)</li> <li> Color-coded intensity plots of polarimetric electric field distributions</li> <li> Incoming ray hits the edge of an obstacledata analysis at each receiver including delay, it is diffracted from that edge. This leads to the creation angles of a cone arrival and departure</li> <li> Cartesian plots of new rays, which greatly complicate the computational problem. The Uniform Theory path loss along defined paths</li> <li> Power delay profile of Diffraction (UTD) is used to calculate the wedge diffraction coefficients at the edges selected receiver</li> <li> Polar stem charts of scattering blocks. Note that reflection, transmission angles of arrival and diffraction coefficients are all dependent on the polarization departure of the incident plane wave.selected receiver</li></ul>

A receiver may receive == Building a large number of rays: direct line-of-sight rays from the transmitter, rays reflected or diffracted off the ground or terrain, rays reflected or diffracted from buildings or rays transmitted through buildings. Each received ray is characterized by its power, delay and angles of arrival, which are the spherical coordinate angles &theta; and &phi; of the incoming ray. The actual signal received and detected by the receiver is the superposition of all these rays with different power levels and different time delays. Most of the time, you will be interested Propagation Scene in the coverage map of an area, which shows how much power is received by a grid of receivers spread over the area from a given fixed transmitterEM.Terrano ==

Click here to learn more about the theory === The Various Elements of [[SBR Method]].a Propagation Scene ===

=== Using SBR as an Asymptotic A typical propagation scene in EM Solver ===.Terrano consists of several elements. At a minimum, you need a transmitter (Tx) at some location to launch rays into the scene and a receiver (Rx) at another location to receive and collect the incoming rays. A transmitter and a receiver together make the simplest propagation scene, representing a free-space line-of-sight (LOS) channel. In EM.Terrano, a transmitter represents a point source, while a receiver represents a point observable. Both a transmitter and a receiver are associated with point objects, which are one of the many types of geometric objects you can draw in the project workspace. Your scene might involve more than one transmitter and possibly a large grid of receivers.

[[EM.Cube]]'s SBR simulation engine can be used as a versatile and powerful asymptotic electromagnetic (EM) solver. If you compare [[EM.Cube]]'s [[Propagation Module]] with its other computational modulesA more complicated propagation scene usually contains several buildings, you will notice a lot of similarities. While walls, or other modules group objects primarily by their material properties, [[Propagation Module]] categorizes the types kinds of scatterers and wave obstructing surfacesobjects. Besides sharing the same ray-surface interaction mechanisms, You model all the of these elements by drawing geometric objects belonging to a surface group also share in the same material propertiesproject workspace or by importing external CAD models. EM. [[Propagation Module]] offers similar source types and similar observable types as Terrano does not organize the other computational modulesgeometric objects of your project workspace by their material composition. For instanceRather, it groups the Hertzian dipole sources used in geometric objects into blocks based on a SBR simulation are identical to those offered in PO, MoM3D and Planar modulescommon type of interaction with incident rays. The plane wave sources are identical across all computational modules. [[Propagation Module]]'s sensor field planes, far field observables (either radiation patterns or RCS) and Huygens surfaces are all fully compatible with [[EM.Cube]]'s other computational modules.Terrano offer the following types of object blocks:

As an asymptotic {| class="wikitable"|-! scope="col"| Icon! scope="col"| Block/Group Type ! scope="col"| Ray Interaction Type! scope="col"| Object Types Allowed! scope="col"| Notes|-| style="width:30px;" | [[File:impenet_group_icon.png]]| style="width:150px;" | [[Glossary of EM solver.Cube's Materials, Sources, Devices & Other Physical Object Types#Impenetrable Surface | Impenetrable Surface]]| style="width:200px;" | Ray reflection, ray diffraction| style="width:250px;" | All solid & surface geometric objects, no curve objects| style="width:300px;" | Basic building group for outdoor scenes|-| style="width:30px;" | [[File:penet_surf_group_icon.png]]| style="width:150px;" | [[Glossary of EM.Cube's Materials, Sources, Devices & Other Physical Object Types#Penetrable Surface | Penetrable Surface]]| style="width:200px;" | Ray reflection, ray diffraction, ray transmission in free space| style="width:250px;" | All solid & surface geometric objects, no curve objects| style="width:300px;" | Behaves similar to impenetrable surface and uses thin wall approximation for generating transmitted rays, the SBR engine can be used to model large-scale electromagnetic radiation hollow buildings with ray penetration, entry and scattering problemsexit |-| style="width:30px;" | [[File:terrain_group_icon. An example png]]| style="width:150px;" | [[Glossary of this kind is radiation of simple EM.Cube's Materials, Sources, Devices & Other Physical Object Types#Terrain Surface | Terrain Surface]]| style="width:200px;" | Ray reflection, ray diffraction| style="width:250px;" | All surface geometric objects, no solid or complex antennas in curve objects | style="width:300px;" | Behaves exactly like impenetrable surface but can change the presence elevation of large scattering platformsall the buildings and transmitters and receivers located above it|-| style="width:30px;" | [[File:penet_vol_group_icon. You have to keep in mind that by using an asymptotic technique in place png]]| style="width:150px;" | [[Glossary of a full-wave methodEM.Cube's Materials, you trade computational speed Sources, Devices & Other Physical Object Types#Penetrable Volume | Penetrable Volume]]| style="width:200px;" | Ray reflection, ray diffraction, ray transmission and lower memory requirements ray attenuation inside homogeneous material media| style="width:250px;" | All solid geometric objects, no surface or curve objects| style="width:300px;" | Used to model wave propagation inside a volumetric material block, also used for modeling accuracycreating individual solid walls and interior building partitions and panels in indoor scenes|-| style="width:30px;" | [[File:base_group_icon. In particularpng]]| style="width:150px;" | [[Glossary of EM.Cube's Materials, Sources, Devices & Other Physical Object Types#Base Location Set | Base Location Set]]| style="width:200px;" | Either ray generation or ray reception| style="width:250px;" | Only point objects| style="width:300px;" | Required for the definition of transmitters and receivers|-| style="width:30px;" | [[SBR MethodFile:scatterer_group_icon.png]]| style="width:150px;" | [[Glossary of EM.Cube's Materials, Sources, Devices & Other Physical Object Types#Point Scatterer Set |SBR methodPoint Scatterer Set]] cannot take into account | style="width:200px;" | Ray reception and ray scattering| style="width:250px;" | Only point, box and sphere objects| style="width:300px;" | Required for the electromagnetic coupling effects among nearby radiators or definition of point scatterersas targets in a radar simulation |-| style="width:30px;" | [[File:Virt_group_icon. However, when your scene spans thousands png]]| style="width:150px;" | [[Glossary of wavelengths, an SBR simulation might often prove to be your sole practical solutionEM. Cube's Materials, Sources, Devices & Other Physical Object Types#Virtual_Object_Group | Virtual Object]]| style="width:200px;" | No ray interaction| style="width:250px;" | All types of objects| style="width:300px;" | Used for representing non-physical items |}

=== Pros and Cons Click on each type to learn more about it in the [[Glossary of EM.TerranoCube's SBR Solver ===Materials, Sources, Devices & Other Physical Object Types]].

[[EM.Terrano]]'s SBR simulation engine utilizes an intelligent ray tracing algorithm Impenetrable surfaces, penetrable surfaces, terrain surfaces and penetrable volumes represent all the objects that is based on obstruct the concept propagation of k-dimensional trees. A k-d tree is a space-partitioning data structure for organizing points electromagnetic waves (rays) in a k-dimensional the free space. k-d trees are particularly useful for searches What differentiates them is the types of physical phenomena that involve multidimensional search keys such as range searches and nearest neighbor searchesare used to model their interaction with the impinging rays. In EM.Terrano discretizes geometric objects into a typical large radio propagation scene, there might be a large number of rays emanating from the transmitter that may never hit any obstaclesflat facets. For exampleThe field intensity, upward-looking rays in an urban propagation scene quickly exit phase and power of the computational domain. Rays that hit obstacles on their path, on the other hand, generate new reflected and transmitted raysdepend on the material properties of the obstructing facet. The kspecular surface of a facet can be modeled locally as a simple homogeneous dielectric half-d tree algorithm traces all these rays systematically in space or as a very fast and efficient mannermultilayer medium. Another major advantage of k-d trees is the fast processing of multi-transmitters scenes. Unlike the previous versions of the SBR solver which could handle one transmitter at a time and would superpose In that respect, all the resulting rays at the end of the simulationobstructing objects such as buildings, the new SBR shoots rays from all the transmitters at the same timewalls, terrain, etc. behave in a similar way:

[[EM.Terrano]]'s SBR solver performs fully polarimetric * They terminate an impinging ray and coherent SBR simulations replace it with arbitrary transmitter antenna patterns. The new engine solves directly for the vectorial field components at the receiver locations one or field observation points. This is far more rigorous than the previous versions of the SBR solver which primarily utilized ray power calculations based on the two vertical and horizontal polarizations. In other words, [[EM.Cube]]'s new SBR engine is a truly asymptotic &quot;field&quot; solverrays. As * They represent a result, you can visualize the magnitude and phase specular interface between two media of all six electric and magnetic field components at any point in the computational domain. For power calculations at different material compositions for calculating the receiver locationreflection, an isotropic, polarization-matched, receiving antenna is assumedtransmission or diffraction coefficients.

In most scenes, An outdoor propagation scene typically involves several buildings modeled by impenetrable surfaces. Rays hit the facets of impenetrable buildings and bounce back, but they do not penetrate the ground or terrain can be object. It is assumed to be made that the interior of homogeneous materials. These are represented by their electrical properties such as permittivity e and electric conductivity sbuildings are highly dissipative due to wave absorption or diffusion. More complex scenes may involve An indoor propagation scene typically involves several walls, a multilayer ground or multilayer ceiling and a floor arranged according to a certain building wallslayout. In such cases, one can no longer use Penetrable surfaces are used to model the simple reflection or transmission coefficient formulas for homogeneous medium interfacesexterior and interior walls of buildings. [[EMRays reflect off these surfaces and diffract off their edges.Cube]] calculates They also penetrate the reflection thin surface and transmission coefficients continue their path in the free space on the other side of multilayer structures the wall. Terrain surfaces with irregular shapes or possibly random rough surfaces are used as functions an alternative to the flat global ground. You can also build mixed scenes involving both impenetrable and penetrable blocks or irregular terrain. In the context of incident anglea propagation scene, frequency and polarization penetrable volumes are often used to model block of rain, fog or vegetation. Base location sets are used to geometrically represent point transmitters and uses them at point receivers in the respective specular pointsproject workspace.

It Sometimes it is very important helpful to keep draw graphical objects as visual clues in mind that SBR is an asymptotic electromagnetic analysis technique that is based on Geometrical Optics (GO) and the Uniform Theory of Diffraction (UTD)project workspace. It is not These non-physical objects must belong to a &quot;full-wave&quot; technique, and it does virtual object group. Virtual objects are not solve Maxwelldiscretized by EM.Terrano's equations directly or numerically. SBR makes a number of assumptionsmesh generator, chief among them, a very high operational frequency such that the length scales involved and they are much larger than not passed onto the operating wavelength. Under this assumed regime, electromagnetic waves start to behave like optical rays. Virtually all input data files of the calculations in SBR are based on far field approximationssimulation engine.

In order to maintain a high computational speed for <table><tr><td> [[Image:PROP MAN2.png|thumb|left|720px|An urban propagation problems, [[scene generated by EM.Cube]]Terrano's SBR solver ignores double diffractions"Random City" and "Basic Link" wizards. Recall that diffractions from edges give rise to It consists of 25 cubic brick buildings, one transmitter and a large number two-dimensional array of new secondary raysreceivers. The power of diffracted rays drops much faster than reflected rays. [[EM.Cube]] ignores diffracted rays that are not detected by any receiver. In other words, an edge-diffracted ray does not diffract again from another edge. However, reflected and penetrated rays do get diffracted from edges just as rays emanated directly from the sources do.</td></tr></table>

== Anatomy Of A = Organizing the Propagation Scene by Block Groups ===

An [[In EM.Cube]] propagation Terrano, all the geometric objects associated with the various scene typically consists of several elements. At a minimumlike buildings, you need a transmitter (Tx) at some terrain surfaces and base location to launch rays into points are grouped together as blocks based on their common type. All the scene and objects listed under a receiver (Rx) at another location to receive particular group in the navigation tree share the same color, texture and collect the incoming raysmaterial properties. A transmitter and Once a receiver together make new block group has been created in the simplest propagation scenenavigation tree, representing a free-space line-it becomes the "Active" group of-sight (LOS) channel. A transmitter is one of [[EM.Cube]]'s several source typesthe project workspace, while a receiver which is one of [[EMalways displayed in bold letters.Cube]]'s several observable typesYou can draw new objects under the active node. A simpler source type is a Hertzian dipole. A simpler observable is a field sensor that is used to compute Any block group can be made active by right-clicking on its name in the electric navigation tree and magnetic fields on a specified planeselecting the '''Activate''' item of the contextual menu.

An outdoor propagation scene may involve several buildings (modeled as impenetrable surfaces) and an underlying flat ground or irregular terrain surface<table><tr><td> [[Image:PROP MAN1. An indoor propagation scene may involve several walls (modeled as thin penetrable surfaces), a ceiling and a floor arranged according to a certain floor planpng|thumb|left|480px|EM. You can also build mixed scenes involving both impenetrable and penetrable blocks, possibly along with irregular terrain surfacesTerrano's navigation tree. Your sources and observables can be placed anywhere in the scene. Your transmitters and receivers can be placed outdoors or indoors. A complete list of the various elements of a propagation scene is given in the '''Physical Structure''' section of [[Propagation Module]]'s Navigation Tree as follows:</td></tr></table>

Impenetrable, penetrable and terrain surfaces all obstruct the propagation of electromagnetic waves {{Note|You can only import external CAD models (rays) in the free spaceSTEP, IGES, STL, DEM, etc. What differentiates them is the types of physical phenomena that are used ) only to model their interaction with the impinging raysCubeCAD module. Base points are simply used to define transmitter and receiver locations in You can then transfer the sceneimported objects from CubeCAD to EM. The following sections of this manual will describe each of these elements in detailTerrano.}}

Figure 1: The Navigation Tree You can move any geometric object or a selection of objects from one block group to another. You can also transfer objects among [[EM.Cube]]'s [[Propagation different modules. For example, you often need to move imported CAD models of terrain or buildings from CubeCAD to EM.Terrano. To transfer objects, first select them in the project workspace or select their names in the navigation tree. Then right-click on them and select <b>Move To &rarr; Module]]Name &rarr; Object Group</b> from the contextual menu. For example, if you want to move a selected object to a block group called "Terrain_1" in EM.Terrano, then you have to select the menu item '''Move To &rarr; EM.Terrano &rarr; Terrain_1''' as shown in the figure below. Note that you can transfer several objects altogether using the keyboards's {{key|Ctrl}} or {{key|Shift}} keys to make multiple selections.

=== <table><tr><td> [[Image:PROP MAN3.png|thumb|left|720px|Moving the terrain model of Mount Whitney originally imported from an external digital elevation map (DEM) file to EM.Terrano.]]</td></tr><tr><td>[[Image:PROP MAN4.png|thumb|left|720px|The Various Types Of Surfaces &amp; Blocks ===imported terrain model of Mount Whitney shown in EM.Terrano's project workspace under a terrain group called "Terrain_1".]]</td></tr></table>

In a SBR simulation, the propagating rays hit the surface === Adjustment of building structures, walls, terrain (or global ground) and bounce back into the scene (reflection). Some rays penetrate thin walls or other penetrable surfaces and continue their path Block Elevation on the other side of the surface (transmission). The field intensity, phase and power of the reflected and transmitted rays depend on the material properties of the obstructing surface. The specular surface can be modeled as a simple homogeneous dielectric half-space or as a multilayer structure. In that respect, the buildings, walls, terrain or even the global ground all behave in a similar way:Underlying Terrain Surfaces ===

* They terminate In EM.Terrano, buildings and all other geometric objects are initially drawn on the XY plane. In other words, the Z-coordinates of the local coordinate system (LCS) of all blocks are set to zero until you change them. Since the global ground is located a z = 0, your buildings are seated on the ground. When your propagation scene has an impinging ray irregular terrain, you would want to place your buildings on the surface of the terrain and replace not buried under it with one or more new rays.* They represent a specular interface between two media This can be done automatically as part of different material compositions for calculating the reflection, transmission definition of the block group. Open the property dialog of a block group and possibly diffraction coefficientscheck the box labeled '''Adjust Block to Terrain Elevation'''. All the objects belonging to that block are automatically elevated in the Z direction such that their bases sit on the surface of their underlying terrain. In effect, the LCS of each of these individual objects is translated along the global Z-axis by the amount of the Z-elevation of the terrain object at the location of the LCS.

[[EM.Cube]] has generalized {{Note| You have to make sure that the concept resolution of '''Block''' as any object that obstructs your terrain, its variation scale and affects radio wave propagationbuilding dimensions are all comparable. Rays hit Otherwise, on a rapidly varying high-resolution terrain, you will have buildings whose bottoms touch the facets of terrain only at a block few points and bounce off the surface parts of those facets or penetrate them and continue their propagation. Rays also get diffracted off hang in the edges of these blocksair. In [[EM.Cube]]'s [[Propagation Module]], blocks are grouped together by the type of their interaction with rays. [[EM.Cube]] currently offers three types of blocks for use in a propagation scene:}}

# '''Impenetrable Surfaces:''' Rays hit the facets of this type of blocks and bounce back, but they do not penetrate the object. It is assumed that the interior of such blocks or buildings are highly absorptive.<table><tr># '''Penetrable Surfaces<td> [[Image:''' These blocks represent thin surfaces that are used to model the exterior and interior walls of buildings based on the &quot;Thin Wall Approximation&quot;PROP MAN5. Rays reflect off the surface png|thumb|left|480px|The property dialog of penetrable surfaces and diffract off their edges. They also penetrate such thin surfaces and continue their paths on the other side of the wall.# '''Terrain Surfaces:''' These blocks are used to provide one or more impenetrable, ground surfaces for surface showing the propagation scene. Rays simply bounce off terrain objects. The global ground acts as a flat super-terrain that covers the bottom of the entire computational domainelevation adjustment box checked. ]]</td></tr></table>

<table><tr><td> [[EMImage:PROP MAN6.png|thumb|left|360px|A set of buildings on an undulating terrain without elevation adjustment.Cube]]'s </td><td>[[Propagation Module]] allows you to define block groups of each Image:PROP MAN7.png|thumb|left|360px|The set of buildings on the above three typesundulating terrain after elevation adjustment. Each block group has the same color or texture and its members share the same material properties: permittivity &epsilon;]]<sub/td>r</subtr> and conductivity &sigma;. Also, all the penetrable surfaces belonging to the same block group have the same wall thickness. You can define many different block groups with certain properties and underneath each introduce many member objects with different geometrical shapes and dimensions. The </table below summarizes the characteristics of each block type:>

{| class="wikitable"|-! scope="col"| Block Type! scopeEM.Terrano's Ray Domain & Global Environment ="col"|Physical Effects! scope="col"|Admissible Object Types|-| Impenetrable Surface| Reflection, Diffraction| All Solid &amp; Surface CAD Objects|-| Penetrable Surface| Reflection, Diffraction, Transmission| All Solid &amp; Surface CAD Objects|-| Terrain Surface| Reflection| Tessellated Objects Only|}

=== Impenetrable Surfaces For Outdoor Scenes Why Do You Need a Finite Computational Domain? ===

[[File:PROP14(2)The SBR simulation engine requires a finite computational domain for ray termination. All the stray rays that emanate from a source inside this finite domain and hit its boundaries are terminated during the simulation process. Such rays exit the computational domain and travel to the infinity, with no chance of ever reaching any receiver in the scene. When you define a propagation scene with various elements like buildings, walls, terrain, etc., a dynamic domain is automatically established and displayed as a green wireframe box that surrounds the entire scene. Every time you create a new object, the domain box is automatically adjusted and extended to enclose all the objects in the scene.png|thumb|200px|[[Propagation Module]]'s Impenetrable Surface dialog]]

In outdoor propagation scenes such as &quot;Urban Canyons&quot;, you are primarily interested in To change the wireless coverage in the areas among buildings. You can assume that rays bounce off the exterior walls of these buildings but do not penetrate them. In other wordsray domain settings, you ignore follow the transmitted rays and assume that they are either absorbed or diffused inside the buildings. This is not an unrealistic assumption. [[EM.Cube]] offers &quot;Impenetrable Blocks&quot; to model buildings in outdoor propagation scenes. A penetrable block has a color or texture property as well as material propertiesprocedure below: permittivity (e_r) and conductivity (s). By default, a brick building is assumed with &epsilon;_r = 4.4 and &sigma; = 0.001 S/m. Impinging rays are reflected from the facets of impenetrable buildings or diffracted from their edges.

To define a new impenetrable block group* Open the Ray Domain Settings Dialog by clicking the '''Domain''' [[File:image025.jpg]] button of the '''Simulate Toolbar''', follow or by selecting '''Menu > Simulate > Computational Domain > Settings...''', or by right-clicking on the '''Ray Domain''' item of the navigation tree and selecting '''Domain Settings...''' from the contextual menu, or simply using the keyboard shortcut {{key|Ctrl+A}}.* The size of the Ray domain is specified in terms of six '''Offset''' parameters along the ±X, ±Y and ±Z directions. The default value of all these steps:six offset parameters is 10 project units. Change these values as you like.* You can also change the color of the domain box using the {{key|Color}} button.* After changing the settings, use the {{key|Apply}} button to make the changes effective while the dialog is still open.

# Right click on either the '''Impenetrable Surfaces''' item of the Navigation Tree and select '''Insert New Block<table><tr><td> [[Image:PROP15.png|thumb|left|480px|EM..''Terrano' A s domain settings dialog for setting up the block properties opens up offering a preloaded material type (Brick) with predefined color and texture.]]# Specify a name for the block group and select a color or texture.</td># The electromagnetic model that determines ray-block interaction is selected under '''Specular Interface Type'''. Two options are available: '''Standard Material''' or '''User Defined Model'''. The former is the default choice and requires material properties, '''Permittivity''' (&epsilon;<sub/tr>r</subtable>) and '''Electric Conductivity''' (&sigma;), which are set to &quot;Brick&quot; by default. No magnetic properties are allowed for blocks.# Click the '''OK''' button of the dialog to accept the changes and close it.

Under an impenetrable block group, you can draw any of [[EM.Cube]]'s native solid or [[Surface Objects|surface objects]] or you can import external model files like STEP, IGES or STL. You can change === Understanding the properties of an impenetrable surface. In the property dialog of the surface group, click on the table that list the properties to select and highlight a row. Then, click the '''Add/Edit''' button to open up the &quot;Edit Layer&quot; dialog. In this dialog, you can change the name of the material and its permittivity and electric conductivity. The box labeled &quot;Specify Loss Tangent&quot; is unchecked by default. If you check it, you can specify the '''Loss Tangent''' of the material, which, in turn, updates the value of electric conductivity at the center frequency of the project. You can also use [[EM.Cube]]'s Material List, which will be explained later. Global Ground ===

[[File:PROP23Most outdoor and indoor propagation scenes include a flat ground at their bottom, which bounces incident rays back into the scene. EM.Terrano provides a global flat ground at z = 0. The global ground indeed acts as an impenetrable surface that blocks the entire computational domain from the z = 0 plane downward. It is displayed as a translucent green plane at z = 0 extending downward. The color of the ground plane is always the same as the color of the ray domain. The global ground is assumed to be made of a homogeneous dielectric material with a specified permittivity &epsilon;_r and electric conductivity &sigma;. By default, a rocky ground is assumed with &epsilon;_r = 5 and &sigma; = 0.005 S/m. You can remove the global ground, in which case, you will have a free space scene. To disable the global ground, open up the "Global Ground Settings" dialog, which can be accessed by right clicking on the '''Global Ground''' item in the Navigation Tree and selecting '''Global Ground Settings... '''Remove the check mark from the box labeled '''&quot;Include Half-Space Ground (z&lt;0)&quot;''' to disable the global ground. This will also remove the green translucent plane from the bottom of your scene. You can also change the material properties of the global ground and set new values for the permittivity and electric conductivity of the impenetrable, half-space, dielectric medium.png]]

Figure: [[Propagation Module]]Alternatively, you can use EM.Terrano's '''Empirical Soil Model''' to define the material properties of the global ground. This model requires a number of parameters: Temperature in &quotdeg;Edit Layer&quot; dialog corresponding to impenetrable surfacesC, and Volumetric Water Content, Sand Content and Clay Content all as percentage.

<table><tr><td> [[FileImage:PROP15(1)Global environ.png|thumb|200pxleft|[[Propagation Module]]720px|EM.Terrano's Penetrable Surface Global Environment Settings dialog.]]</td></tr></table>

A typical indoor propagation scene usually involves an arrangement of walls that represent the interior of a building. The transmitters and receivers are then placed in the spaces among such walls. From the point of view of [[EM.Cube]]'s SBR simulator, walls act like thin penetrable surfaces. [[EM.Cube]] uses the == Defining Point Transmitters &quot;Thin Wall Approximation&quot; to model penetrable surfaces. It assumes that rays simply penetrate a wall and exit at the same specular point on the opposite side of the wall. In other words, rays are not displaced by the walls, nor do they get trapped inside the walls (no internal reflection). This is equivalent to assuming a zero thickness for penetrable surfaces for the purpose of geometrical ray tracing, while the finite thickness of the &quot;thin&quot; surface is used for electromagnetic calculation of transmission coefficient. [[EM.Cube]] offers &quot;Penetrable Surface Blocks&quotamp; Point Receivers for the construction of rooms in indoor propagation scenes as well as modeling of hollow buildings and other structures. You can define many penetrable surface groups with arbitrary thicknesses and material properties (color, texture, permittivity and electric conductivity).Your Propagation Scene ==

# Right click on one In EM.Terrano, transmitters and receivers are indeed point radiators used for transmitting and receiving signals at different locations of the '''Penetrable Surfaces''' item propagation scene. From a geometric point of view, both transmitters and receivers are represented by point objects or point arrays. These are grouped as base locations in the Navigation Tree "Physical Structure" section of the navigation tree. As radiators, transmitters and select '''Insert New Block...''' A dialog for setting up the wall properties opens up offering receivers are defined by a preloaded material radiator type (Brick) with predefined color and texture.# Specify a name for the surface group and select a color or texturecertain far-field radiation pattern.# The properties of a penetrable surface Consistent with [[EM.Cube]]'s other computational modules, transmitters are identical to those of categorizes as an impenetrable surfaceexcitation source, plus an additional thickness propertywhile receivers are categorized as a project observable.# By defaultIn other words, a brick wall with a thickness of 0.5 units transmitter is assumedused to generate electromagnetic waves that propagate in the physical scene. You can change A receiver, on the '''Thickness''' of other hand, is used to compute the penetrable surface as well as its '''Permittivity''' &epsilon;_r received fields and '''Electric Conductivity''' &sigma;received signal power or signal-to-noise ratio (SNR).# Click For this reason, transmitters are defined and listed under the '''OK''' button "Sources" sections of the dialog to accept navigation tree, while receivers are defined and listed under the changes and close it"Observables" section.

Under a penetrable surface group, you can draw any of [[EM.Cube]]'s native solid or [[Surface Objects|surface objects]] or you can import external model files like STEP, IGES or STL. You can change the properties of a penetrable surface group including its default thickness. In the property dialog of the surface group, click on the table that list the properties to select and highlight a row. Then, click the '''Add/Edit''' button to open up the &quot;Edit Layer&quot; dialog. Similar to the case of impenetrable surfaces, from this dialog, you can change the material properties (permittivity and electric conductivity) as well as '''Thickness''', which is expressed in the project units. You can also use [[EM.Cube]]'s Material List, which will be explained later.Terrano provides three radiator types for point transmitter sets:

Figure 2: [[Propagation Module]]'s &quot;Edit Layer&quot; dialog corresponding to penetrable surfacesEM.Terrano also provides three radiator types for point receiver sets:

You can construct several thin walls and arrange them as rooms. A regular room can be built by placing four vertical wall objects together with an optional horizontal wall at #Half-wave dipole oriented along one of the top for the ceiling. Alternatively, you may use [[EM.Cube]]'s hollow box objects or boxes with one or two capped endthree principal axes#Polarization-matched isotropic radiator#User defined (sarbitrary). '''Keep in mind that all the penetrable surfaces belonging to a group have the same wall thickness, which is initially set to 0.5 project units by default. Also, note that solid CAD objects belonging to a penetrable surface group are treated as airantenna with imported far-filled hollow structures.''' The thickness of penetrable surfaces is implied and not visualized when displaying objects in the project workspace.field radiation pattern

The SBR simulation engine requires a finite computational domain. All the stray rays that hit the boundaries of this finite domain There are terminated during the simulation process. Such rays exit the computational domain and travel three different ways to the infinity, with no chance of ever reaching any receiver in the scene. When you define a propagation scene with various elements like buildings, walls, terrain, etc., transmitter set or a dynamic domain is automatically established and displayed as a wireframe box with green lines that surrounds the entire scene. Every time you create a new object, the domain is automatically adjusted and extended to enclose all the objects in the scene. You can change the size and color of the domain box through the Ray Domain Settings Dialog, which can be accessed in one of the following three waysreceiver set:

# Click *By defining point objects or point arrays under physical base location sets in the '''Domain''' [[File:image025.jpg]] button of the Simulation Toolbar.navigation tree and then associating them with a transmitter or receiver set# Select the '''Simulate''' &gt; '''Computational Domain''' &gt; '''Settings...''' item of the Simulate Menu.# Right click on the '''Ray Domain''' item of the Navigation Tree *Using Python commands emag_tx, emag_rx, emag_tx_array, emag_rx_array, emag_tx_line and select '''Domain Settings...'''emag_rx_line# Use *Using the keyboard shortcut '''Ctrl + A'''."Basic Link" wizard

The size of the Ray domain is specified === Defining a Point Transmitter Set in terms of six '''Offset''' [[parameters]] along the ±X, ±Y and ±Z directions. The default value of all these six offset [[parameters]] is 10 project units. You can change them arbitrarily. After changing these values, use the '''Apply''' button to make the changes effective while the dialog is still open.Formal Way ===

[[File:PROP15Transmitters act as sources in a propagation scene.png]]A transmitter is a point radiator with a fully polarimetric radiation pattern defined over the entire 3D space in the standard spherical coordinate system. EM.Terrano gives you three options for the radiator associated with a point transmitter:

Most outdoor and indoor propagation scenes include a flat ground at their bottomBy default, which bounces incident rays back into the scene. [[EM.Cube]]'s [[Propagation Module]] provides a global flat ground at z = 0. The global ground indeed acts as an impenetrable surface Terrano assumes that blocks the entire computational domain from the z = 0 plane downward. It your transmitter is displayed as a translucent green plane at z = 0 extending downward. The color of the ground plane is always the same as the color of the ray domain. The global ground is assumed to be made of a homogeneous dielectric material with a specified permittivity &epsilon;_r and electric conductivity &sigma;. By default, a rocky ground is assumed with &epsilon;_r = 5 and &sigma; = 0.005 S/m. You can remove the global ground, in which case, you will have a free space scene. To disable the global ground, open up the Global Ground Settings Dialog, which can be accessed by right clicking on the '''Global Ground''' item in the Navigation Tree and selecting '''Global Ground Settings... '''Remove the check mark from the box labeled '''&quot;Include Halfvertically polarized (Z-Space Ground (z&lt;0directed)&quot;''' to disable the global groundresonant half-wave dipole antenna. This will antenna has an almost omni-directional radiation pattern in all azimuth directions. It also remove has radiation nulls along the green translucent plane from axis of the bottom of your scenedipole. You can also change the material properties direction of the global ground dipole and set new values for orient it along the permittivity and electric conductivity of X or Y axes using the impenetrable, halfprovided drop-space, dielectric mediumdown list. '''Do not forget to disable the global ground if you want to model a free space propagation sceneThe second choice of two orthogonally polarized isotropic radiators is an abstract source that is used for polarimetric channel characterization as will be discussed later.'''

You can override the default radiator option and select any other kind of antenna with a more complicated radiation pattern. For this purpose, you have to import a radiation pattern data file to EM.Terrano. You can model any radiating structure using [[File:PROP4EM.pngCube]]'s other computational modules, [[EM.Tempo]], [[EM.Picasso]], [[EM.Libera]] or [[EM.Illumina]], and generate a 3D radiation pattern data file for it. The far-field radiation patter data are stored in a specially formatted file with a &quot;'''.RAD'''&quot; file extension. This file contains columns of spherical &phi; and &theta; angles as well as the real and imaginary parts of the complex-valued far-zone electric field components '''E_&theta;''' and '''E_&phi;'''. The &theta;- and &phi;-components of the far-zone electric field determine the polarization of the transmitting radiator.

Figure 2: [[Propagation Module]]'s Global Ground Settings dialog{{Note|By default, EM.Terrano assumes a vertical half-wave dipole radiator for your point transmitter set.}}

=== Terrain Surfaces vsA transmitter set always needs to be associated with an existing base location set with one or more point objects in the project workspace. Global Ground ===Therefore, you cannot define a transmitter for your scene before drawing a point object under a base location set.

[[FileImage:PROP16Info_icon.png|thumb|200px|[[Propagation Module40px]]Click here to learn how to define a 's Terrain dialog''[[Glossary_of_EM.Cube%27s_Materials,_Sources,_Devices_%26_Other_Physical_Object_Types#Point_Transmitter_Set | Point Transmitter Set]]'''.

A terrain surface acts as a custom, unlevel or irregular ground for your propagation scene. <table><tr><td> [[EMImage:Terrano L1 Fig11.png|thumb|left|480px|The point transmitter set definition dialog.Cube]]'s default global ground blocks the z &lt; 0 half-space everywhere in the computational domain. You can simply turn off the global ground and create one or more terrain objects and place them arbitrarily in the scene. You can also import an external terrain model or file. A terrain represents an impenetrable surface with a more complex surface profile. You can have one or more terrain objects of finite extents and place them on or above the global ground.</td></tr></table>

Terrain objects have some important differences Once you define a new transmitter set, its name is added in the '''Transmitters''' section of the navigation tree. The color of all the base points associated with objects the newly defined transmitter set changes, and an additional little ball with the transmitter color (red by default) appears at the location of each associated base point. You can open the property dialog of the transmitter set and modify a number of parameters including the '''Source Power''' in Watts and the broadcast signal '''Phase''' in degrees. The default transmitter power level is 1W or 30dBm. There is also a check box labeled '''Use Custom Input Power''', which is checked by default. In that case, the power and phase boxes are enabled and you can change the default 1W power and 0&deg; phase values as you wish. [[EM.Cube]]'s ".RAD" radiation pattern files usually contain the value of &quot;Impenetrable SurfaceTotal Radiated Power&quot; type:in their file header. This quantity is calculated based on the particular excitation mechanism that was used to generate the pattern file in the original [[EM.Cube]] module. When the "Use Custom Input Power" check box is unchecked, EM.Terrano will use the total radiated power value of the radiation file for the SBR simulation.

# While impenetrable blocks can be created using {{Note|In order to modify any of [[EM.Cube]]the transmitter set's solid or surface CAD object creation toolsparameters, terrain objects are created either using [[EM.Cube]]'s '''Terrain Generator''' or by importing an external terrain file. # Terrain objects belong first you need to a special type of CAD objects called &quot;Tessellated Objects&quot;select the "User Defined Antenna" option, which differ from other regular CAD [[Surface Objects|surface objects]] or [[EM.Cube]]'s polymesh surfaces.# Terrain surfaces do not diffract impinging rays at their many small edges.# Terrain objects affect even if you want to keep the elevation of other objects or transmitters or receivers that are located above themvertical half-wave dipole as your radiator.}}

Just as other blocks are grouped by their color, texture and material composition, terrain objects are also grouped in <table><tr><td> [[File:NewTxProp.png|thumb|left|720px|The property dialog of a similar fashionpoint transmitter set. Before you can generate or import a new terrain object, first you have to define a terrain group and specify its color]]</texture and material properties. To define a new terrain group, follow these steps:td></tr></table>

* Right click on the '''Terrain''' item Your transmitter in the Navigation Tree and select '''Insert New TerrainEM...''' A dialog for setting up the terrain properties opens up offering Teranno is indeed more sophisticated than a simple radiator. It consists of preloaded material type (Rock) a basic "Transmitter Chain" that contains a voltage source with predefined green color and no texture.* Specify a name for the terrain group series source resistance, and select connected via a color or texture.* Similar segment of transmission line to other blocksa transmit antenna, which is used to launch the broadcast signal into the free space. The transmitter's property dialog allows you have to define the basic transmitter chain. Click the {{key|Transmitter Chain}} button of the Transmitter Set dialog to open the transmitter chain dialog. As shown in the figure below, you can specify the material propertiescharacteristics of the baseband/IF amplifier, Permittivity mixer and power amplifier (&epsilon;_rPA) including stage gains and Electric Conductivity impedance mismatch factors (&sigma;IMF), as well as the characteristics of the terrain group. Rock with &epsilon;_r = 5 and &sigma; = 0.005 S/m is transmission line segment that connects the default material choice for a new terrainPA to the antenna.* Click Note that the '''OK''' button transmit antenna characteristics are automatically filled using the contents of the imported radiation pattern data file. The transmitter Chain dialog to accept the changes also calculates and reports the "Total Transmitter Chain Gain" based on your input. When you close itthis dialog and return to the Transmitter Set dialog, you will see the calculated value of the Effective Isotropic Radiated Power (EIRP) of your transmitter in dBm.

You can change {{Note| If you do not modify the properties default parameters of a terrain surface group from its property dialog. Click on the table that list the properties to select and highlight transmitter chain, a row. Then, click the '''Add/Edit''' button to open up the 50-&quotOmega;Edit Layer&quot; dialog, which conjugate match condition is identical assumed and the power delivered to the case of impenetrable surfacesantenna will be -3dB lower than your specified baseband power. You can also use }} <table><tr><td> [[File:NewTxChain.png|thumb|left|720px|EM.Cube]]Terrano's Material List, which will be explained laterpoint transmitter chain dialog. When a new terrain type is created, its node on the Navigation Tree becomes active. Under this node you can create and add new terrain objects. When a terrain node is active for drawing, all CAD object creation tools are disabled. You have three options for creating a new terrain object, which will be described in detail in the next sections of this manual:]] </td></tr></table>

Click here Receivers act as observables in a propagation scene. The objective of a SBR simulation is to learn more about [[Using Terrain Generator]]calculate the far-zone electric fields and the total received power at the location of a receiver. You need to define at least one receiver in the scene before you can run a SBR simulation. Similar to a transmitter, a receiver is a point radiator, too. EM.Terrano gives you three options for the radiator associated with a point receiver set:

You can import two types of terrain in [[EMmay also define a complicated radiation pattern for your receiver set.Cube]]'s [[Propagation Module]]. The first type is &quot;'''.TRN&quot;''' terrain fileIn that case, which is [[EM.Cube]]'s native terrain format. It is you need to import a basic digital elevation map with a very simple ASCII radiation pattern data file formatto EM. The resolution of Terrano similar to the terrain map in the X and Y directions is specified in meters as STEPS. The (x, y, z) coordinates case of the terrain points are then listed one point per line. The other type of terrain format supported by [[EM.Cube]] is the standard '''7.5min DEM''' file format with a '''.DEM''' file extensiontransmitter set.

To import an external terrain model{{Note|By default, first you have to create EM.Terrano assumes a terrain group node in the Navigation Tree. Right click on the name of the terrain group in the Navigation Tree and select either '''Import Terrain...''' or '''Import DEM File...''' A standard [[Windows]] '''Open Dialog''' opens up, with the file type vertical half-wave dipole radiator for your point receiver set to .TRN or .DEM extensions, respectively. You can browse your folders and find the right terrain model file to import.}}

You can also export all the terrain Similar to transmitter sets, you define a receiver set by associating it with an existing base location set with one or more point objects in the project workspace as a terrain file with a '''.TRN''' file extensionAll the receivers belonging to the same receiver set have the same radiator type. You can even import a DEM terrain model from an external file and then save and export it as A typical propagation scene contains one or few transmitters but usually a native terrain (.TRN) filelarge number of receivers. To export the terraingenerate a wireless coverage map, select '''File''' &gt; '''Export...''' from [[Propagation Module]]'s '''File Menu'''. The standard [[Windows]] Save Dialog opens up with the default file type set you need to '''.TRN'''. Type in a name for define an array of points as your new terrain file and click the '''Save''' button to export the terrain database location set.

[[FileImage:prop_manual-12_tnInfo_icon.png|800px40px]]Click here to learn how to define a '''[[Glossary_of_EM.Cube%27s_Simulation_Observables_%26_Graph_Types#Point_Receiver_Set | Point Receiver Set]]'''.

Figur<table><tr><td> [[Image: An imported external terrain modelTerrano L1 Fig12.png|thumb|left|480px|The point receiver set definition dialog.]] </td></tr></table>

<table><tr><td> [[File:PROP26NewRxProp.png|thumb|200pxleft|Propagation Module's Penetrable Surface Dialog showing 720px|The property dialog of a three-layer wall compositionpoint receiver set.]]</td></tr></table>

Most of the time, your outdoor propagation scene consists of simple buildings made of single-layer walls with standard material properties (&epsilon;_r and &sigma;). In the case of a single-layer impenetrable surfaceReceiver Set dialog, the specular interface there is an infinite dielectric halfa drop-spacedown list labeled '''Selected Element''', which reflects contains a list of all the impinging raysindividual receivers belonging to the receiver set. Single-layer penetrable surfaces, on At the other handend of an SBR simulation, involve finite-thickness dielectric walls, which both reflect and transmit the incident raysbutton labeled {{key|Show Ray Data}} becomes enabled. SimilarlyClicking this button opens the Ray Data dialog, most where you can see a list of your indoor propagation scenes involve simple single-layer penetrable walls with all the specified material properties &epsilon;_r and &sigma;. A thin wall acts like a finite-thickness dielectric slab that both reflects and transmits incident received rays. In at the case of the global ground or terrain objects, only ray reflection off the ground surface is consideredselected receiver and their computed characteristics.

In [[EMIf you choose the "user defined antenna" option for your receiver set, it indeed consists of a basic "Receiver Chain" that contains a receive antenna connected via a segment of transmission line to the low-noise amplifier (LNA) that is terminated in a matched load.Cube]]The receiver set's [[Propagation Module]], property dialog allows you can to define multilayer surfaces with both reflection and transmission propertiesthe basic receiver chain. You can define multilayer impenetrable buildings, multilayer penetrable walls, and multilayer terrain, with an arbitrary number Click the {{key|Receiver Chain}} button of layers having different material compositionsthe Receiver Set dialog to open the receiver chain dialog. You define a multilayer surface As shown in the property dialog figure below, you can specify the characteristics of a block, whether impenetrable, penetrable or terrainthe LNA such as its gain and noise figure in dB as well as the characteristics of the transmission line segment that connects the antenna to the LNA. In Note that the section entitled '''Surface Type''', two options receiving antenna characteristics are available: automatically filled from using contents of the radiation file. You have to enter values for antenna's ''Standard Material'Brightness Temperature'' or '''User Defined Model'''. For simple multilayer walls, select as well as the '''Standard Material''' option. You can add new layers with arbitrary thickness and material [[parameters]] to temperature of the existing layers. To insert a new layer, deselect any items in the layer list, transmission line and click the receiver's ambient temperature. The effective ''Add/Edit'Receiver Bandwidth'' button ' is assumed to open the &quot;Add Layer&quot; Dialog. Here be 100MHz, which you can enter a name change for the new layer purpose of noise calculations. The Receive Chain dialog calculates and values for its '''Thickness''', &epsilon;_r reports the "Noise Power" and &sigma;"Total Receiver Chain Gain" based on your input. You may also delete any layer by selecting At the end of an SBR simulation, the receiver power and highlighting it signal-noise ratio (SNR) of the selected receiver are calculated and clicking they are reported in the '''Delete''' buttonreceiver set dialog in dBm and dB, respectively. You can move layers up or down using examine the '''Move Up''' properties of all the individual receivers and '''Move Down''' buttons and change all the layer hierarchyindividual rays received by each receiver in your receiver set using the "Selected Element" drop-down list.

You can also search <table><tr><td> [[File:NewRxChain.png|thumb|left|720px|EM.Cube]]Terrano's material database by clicking the '''Material''' button of &quot;Add Layer&quot; or &quot;Edit Layer&quot; dialogs. This opens the '''Materials''' Dialog. Inside the material list select and highlight any row and click the '''OK''' button. The selected material will fill out all the fields in the &quot;Add Layer&quot; or &quot;Edit Layer&quot; dialogs. Inside the Materials Dialog, you can type the few first letters of any material, and it will take you to the corresponding row of the listpoint receiver chain dialog.]] </td></tr></table>

Figure: [[EM.Cube]]'s material listTerrano allows you to define a digital modulation scheme for your communication link.There are currently 17 waveforms to choose from in the receiver set property dialog:

*OOK*M-ary ASK*Coherent BFSK*Coherent QFSK*Coherent M-ary FSK*Non-Coherent BFSK*Non-Coherent QFSK*Non-Coherent M-ary FSK*BPSK*QPSK*Offset QPSK*M-ary PSK*DBPSK*pi/4 Gray-Coded DQPSK*M-ary QAM*MSK*GMSK (BT === Transferring Objects From Or To Other Modules ===0.3)

When In the above list, you start a new project in [[EMneed to specify the '''No.Cube]]Levels (M)'s [[Propagation Module]] and draw a solid object like a box in '' for the project workspace without having defined any surface groupsMary modulation schemes, it is assumed to be of from which the impenetrable surface type'''No. A default impenetrable surface group called Block_1 Bits per Symbol''' is automatically added to determined. You can also define a bandwidth for the Navigation Treesignal, which holds your newly drawn object. The has a default group has value of 100MHz. Once the material properties SNR of &quot;Brick&quot; (&epsilon;the signal is found, given the specified modulation scheme, the E_rb = 4.4 and &sigma; = /N<sub>0.001 S</m.) with a dark brown color. You can continue drawing new objects in the project workspace and adding them under this block node. Or you can define a new surface type with different properties. By defaultsub> parameter is determined, from which the last surface group that was defined bit error rate (BER) is '''Active'''. The current active surface group is always listed in bold letters in the Navigation Tree. When you draw a new object, it is always inserted under the current active surface group. Any surface group can be activated by right clicking its name in the Navigation Tree and selecting the '''Activate''' item of the contextual menucalculated.

You can move any object from its current surface group into any other available surface group. First select The Shannon – Hartley Equation estimates the object, then right click on its surface and select '''MoveTo &gt; Propagation &gt;'''. A submenu appears which lists all the available surface groups where you can transfer the selected object. You can also move objects among surface groups by selecting their names in the Navigation Tree and using the contextual menu. In a similar way, you can transfer objects from [[Propagation Module]] to [[EM.Cube]]'s other modules or vice versa. '''Keep in mind that all the external model files such as STEP, IGES, STL, etc. are first imported to [[EM.Cube]]'s [[CubeCAD]], from which you can transfer them to other modules.''' First select the object, then right click and select '''MoveTo &gt;'''. In the submenu you will see a list of all the [[EM.Cube]] modules that have at least one available group where you can transfer your selected object. You can select multiple objects for transfer. When using the keyboard's '''Shift Key''' or '''Ctrl Key''' for multiple selection, make sure that those keys are held down, when you right click to access the contextual menu.channel capacity:

<math> C == Defining Sources &amp; Observables ==B \log_2 \left( 1 + \frac{S}{N} \right) </math>

Like every other electromagnetic solverwhere B in the bandwidth in Hz, [[EM.Cube]]'s SBR ray tracer requires a source for excitation and one or more observables for generation of simulation C is the channel capacity (maximum data. [[EM.Cube]]'rate) expressed in bits/s new [[Propagation Module]] offers several types of sources and observables for a SBR simulation. You can mix and match different source types and observable types depending on the requirements of your modeling problem. There are two types of sources:

The simplest SBR simulation can be performed using a short dipole source with a specified field sensor plane. In this way, [[EM.Cube]] computes the electric and magnetic fields radiated by your dipole source in the presence of your multipath propagation environment. A &quot;classic&quot; urban propagation scene can be set up using a &quot;Transmitter&quot; source and an array of &quot;Receiver&quot; observables. A transmitter is a point radiator with a user defined radiation pattern. A receiver is a polarization<math> \frac{E_b}{N_0} = \frac{ 2^\eta -matched isotropic point radiator that collects the received rays at its aperture. Using receivers, you can calculate the received power coverage map of your propagation scene. You can also calculate your channel's path loss between the transmitter and all the receivers. 1}{\eta} <br /math>

[[File:PROP18(1).png|thumb|[[Propagation Module]]'s Transmitter dialog with a short dipole radiator selected]]Earlier versions of [[EM.Cube]]'s [[Propagation Module]] used to offer an isotropic radiator with vertical or horizontal polarization as The relationship between the bit error rate and E_b/N₀ depends on the simplest transmitter modulation scheme and detection type(coherent vs. This release of [[EMnon-coherent).Cube]] has abandoned isotropic radiator transmitters because they do not exist physically in a real world. InsteadFor example, the default transmitter radiator type is now a Hertzian dipole. Note that before defining a transmitterfor coherent QPSK modulation, first you have to define a base set to establish the location of the transmitter. Most simulation scenes involve only a single transmitter. Your base set one can be made up of a single point for this purpose. write:

To define a new Transmitter Set, go to the '''Sources''' section of the Navigation Tree, <math> P_b = 0.5 \; \text{erfc} \left( \sqrt{ \frac{E_b}{N_0} } \right click on ) </math> where P_b is the '''Transmitters''' item bit error rate and select '''Insert Transmitter...''' A dialog opens up that contains a default name for erfc(x) is the new Transmitter Set as well as a dropdown list labeled '''Select Base Set'''. In this list you will see all the available base sets already defined in the project workspace. Select the desired base set to associate with the transmitter set. Note that if the base set contains more than one point, then more than one transmitter will be created and contained in your transmitter set. After defining a transmitter set, the base points change their color to the transmitter color, which is red by default.complementary error function:

In the &quot;Radiator&quot; section of the dialog, you have two options to choose from: &quot;Short Dipole&quot; and &quot;User Defined&quot;. The default option is short dipole. A short dipole radiator has a '''Length'''''dl'' expressed in project units, a current '''Amplitude''' in Amperes and a current '''Phase''' in degrees. The '''Direction''' of the dipole is determined by its unit vector that has three X, Y and Z components. By default, a Z<math> \text{erfc}(x) = 1-directed short dipole radiator is assumed. You can change all [[parameters]] of the dipole as you wish. Keep in mind that all the transmitters belonging to the same set have parallel radiators with identical properties.\text{erf}(x) = \frac{2}{\sqrt{\pi}} \int_{x}^{\infty} e^{-t^2} dt </math>

[[File:PROP1=== A Note on EM.png|thumb|[[Propagation Module]]Terrano's Base Set dialog]]In order to tie up transmitters and receivers with CAD objects in the project workspace, [[EM.Cube]] uses point objects to define transmitters and receivers. These point objects represent the base of the location of transmitters and receivers in the computational domain. Hence, they are grouped together as &quot;Base Sets&quot;. You can easily interchange the role of transmitters and receivers in a scene by switching their associated bases. The usefulness of concept of base sets will become apparent later when you place transmitters or receivers on an irregular terrain and adjust their elevation. Native Dipole Radiators ===

To create When you define a new base transmitter set or a new receiver set, right click on EM.Terrano assigns a vertically polarized half-wave dipole radiator to the '''Base Sets''' item set by default. The radiation pattern of Navigation Tree this native dipole radiators is calculated using well-know expressions that are derived based on certain assumptions and select '''Insert Base Setapproximations...''' A dialog for setting up For example, the Base Set properties opens up.far-zone electric field of a vertically-polarized dipole antenna can be expressed as:

Once a base set node has been added to the Navigation Tree<math> E_\phi(\theta, it becomes the active node for new object drawing. Under base sets, you can only draw point objects. All other object creation tools are disabled. A point is initially drawn on the XY plane. Make sure to change the Z-coordinate of your radiator, otherwise, it will fall on the global ground at z = \phi) \approx 0. You can also create arrays of base points under the same base set. This is particularly useful for setting up receiver grids to compute coverage maps. Simply select a point object and click the '''Array Tool''' of '''Tools Toolbar''' or use the keyboard shortcut &quot;A&quot;. Enter values for the X, Y or Z spacing as well as the number of elements along these three directions in the Array Dialog. In most propagation scenes you are interested in 2D horizontal arrays along a fixed Z coordinate (parallel to the XY plane). </math>

where k₀ =2&pi;/&lambda;₀ is the free-space wavenumber, &lambda;₀ is the free-space wavelength, &eta;₀ == Defining Transmitter Sets === 120&pi; &Omega; is the free-space intrinsic impedance, I₀ is the current on the dipole, and L is the length of the dipole.

A short dipole is the closest thing to an omni-directional radiator. The direction or orientation directivity of the short dipole determines its polarization. In many applications, you may rather want to use a directional antenna for your transmitter. You can model a radiating structure using [[EM.Cube]]'s FDTD, Planar, MoM3D or PO modules and generate a 3D radiation pattern data file for it. These data are stored in a specially formatted file with a &quot;'''.RAD'''&quot; extension, which contains columns of spherical &phi; and &theta; angles as well as the real and imaginary parts of the complex-valued far field components '''E_&theta;''' and '''E_&phi;'''. The &theta;- and &phi;-components of the far-zone electric field determine the polarization of is given be the transmitting radiator. expression:

To define a directional transmitter radiator, you need to select the &quot;User Defined&quot; option in the &quot;Radiator&quot; section of the Transmitter Dialog. You can do this either at the time of creating a transmitter set, or afterwards by opening the property dialog of the transmitter set. In the &quot;Custom Pattern <math> D_0 \approx \frac{2}{F_1(k_0L) + F_2(k_0L) + F_3(k_0L)} \left[[Parameters]]&quot;, click the '''Import Pattern''' button to set the path for the radiation data file. This opens up the standard [[Windows]] Open dialog, with the default file type or extension set to &quot;.RAD&quot;. Browse your folders to find the \frac{\text{cos} \left( \frac{k_0 L}{2} \text{cos} \theta \right) - \text{cos} \left( \frac{k_0 L}{2} \right) }{\text{sin}\theta} \right data file. A radiation pattern file usually contains the value of &quot;Total Radiated Power&quot; in its file header. This is used by default for power calculations in the SBR simulation. However, you can check the box labeled &quot;'''Custom Power'''&quot; and enter a value for the transmitter power in Watts. [[EM.Cube]] can also rotate the imported radiation pattern arbitrarily. In this case, you need to specify the '''Rotation''' angles in degrees about the X-, Y- and Z-axes. Note that these rotations are performed sequentially and in order: first a rotation about the X-axis, then a rotation about the Y-axis, and finally a rotation about the Z-axis. ^2 </math>

<math> F_2(x) === Multiple Transmitters vs. Antenna Arrays ===\frac{1}{2} \text{sin}(x) \left[ S_i(2x) - 2S_i(x) \right] </math>

<math> F_3(x) = \frac{1}{2} \text{cos}(x) \left[[EM.Cube\gamma + \text{ln}(x/2) + C_i(2x) - 2C_i(x) \right]]'s SBR simulations are fully coherent and 3D-polarimetric. This means that the phase and polarization of all the rays are maintained and processed during their bounces in the scene. Your propagation scene can have more than one transmitter. During an SBR simulation, all the rays emanating from all the transmitters are traced in the propagation scene. All the received rays at a given receiver location are summed coherently and vectorially. This is based on the principle of linear superposition. All the transmitters belonging to the same transmitter set have the same radiation properties. They are either parallel short dipole radiators with the same current amplitudes and phases, or parallel user defined radiators with identical radiation patterns. As these transmitters are placed at different spatial locations, they effectively form an antenna array with identical elements. The array factor is simply determined by the coordinates of the base points. If you want to have different amplitude or phases, then you need to define different transmitter sets. </math>

where &gamma; === Defining Receiver Sets ===0.5772 is the Euler-Mascheroni constant, and C_i(x) and S_i(x) are the cosine and sine integrals, respectively:

[[File:PROP21<math> S_i(1x).png]] [[File:PROP22.png]]= \int_{0}^{x} \frac{ \text{sin} \tau}{\tau} d\tau </math>

In the case of a half-wave dipole, L =&lambda;₀/2, and D₀ =1.643. Moreover, the input impedance of the dipole antenna is Z_A = Defining Field Sensors === 73 + j42.5 &Omega;. These dipole radiators are connected via 50&Omega; transmission lines to a 50&Omega; source or load. Therefore, there is always a certain level of impedance mismatch that violates the conjugate match condition for maximum power.

<table><tr><td> [[File:PMOM90Dipole radiators.png|thumb|[[Propagation Module]]720px|EM.Terrano's Field Sensor dialognative half-wave dipole transmitter and receiver.]]</td>As an asymptotic electromagnetic field solver, the SBR simulation engine can compute the electric and magnetic field distributions in a specified plane. In order to view these field distributions, you must first define field sensor observables before running the SBR simulation. To do that, right click on the '''Field Sensors''' item in the '''Observables''' section of the Navigation Tree and select '''Insert New Observable...'''. The Field Sensor Dialog opens up. At the top of the dialog and in the section titled '''Sensor Plane Location''', first you need to set the plane of field calculation. In the dropdown box labeled '''Direction''', you have three options X, Y, and Z, representing the&quot;normals&quot; to the XY, YZ and ZX planes, respectively. The default direction is Z, i.e. XY plane parallel to the substrate layers. In the three boxes labeled '''Coordinates''', you set the coordinates of the center of the plane. Then, you specify the '''Size''' of the plane in project units, and finally set the '''Number of Samples''' along the two sides of the sensor plane. The larger the number of samples, the smoother the near field map will appear. </tr></table>

In On the section titled Output Settingsother hand, we you can also select specify a user-defined antenna pattern for the field map type from two options: '''Confetti''' and '''Cone'''. The former produces an intensity plot for field amplitude and phasetransmitter or receiver sets, while the latter generates you import a 3D vector plot. In radiation pattern file that contains all the confetti case, you have an option to check values of E_&theta; and E_&phi; for all the box labeled '''Data Interpolation'''combinations of (&theta;, which creates a smooth and blended (digitally filtered&phi;) mapangles. In Besides the cone casethree native dipole radiators, you can set the size of the vector cones that represent the field direction[[EM. At the end of a sweep simulationCube]] also provides 3D radiation pattern files for three X-, multiple field map are produced Y- and added to the Navigation Tree. You can animate these maps. However, during the sweep only one field type is stored, either the EZ-field or Hpolarized half-fieldwave resonant dipole antennas. You can choose the field type for multiple plots These pattern data were generated using the radio buttons in the section titled '''Field Display a full- Multiple Plots''wave solver like [[EM.Libera]]'s wire MOM solver. The default choice is names of the E-field. radiation pattern files are:

Once you close the Field Sensor dialog, its name is added under the '''Field Sensors''' node of the Navigation Tree* DPL_STD_X. At the end of a SBR simulation, the field sensor nodes in the Navigation Tree become populated by the magnitude and phase plots of the three vectorial components of the electric ('''E''') and magnetic ('''H''') field as well as the total electric and magnetic fields defined in the following manner:RAD* DPL_STD_Y.RAD* DPL_STD_Z.RAD

:<math> and they are located in the folder "\mathbf{|E_{tot}|} = Documents\sqrt{|E_x|^2 + |E_y|^2 + |E_z|^2} </math>EMAG\Models" on your computer. Note that these are full-wave simulation data and do not involve any approximate assumptions. To use these files as an alternative to the native dipole radiators, you need to select the '''User Defined Antenna Pattern''' radio button as the the radiator type in the transmitter or receiver set property dialog.

:<math> \mathbf{|H_{tot}|} = \sqrt{|H_x|^2 + |H_y|^2 + |H_z|^2} </math><!--[[File:PMOM88.png]]-->== A Note on the Rotation of Antenna Radiation Patterns ===

=== Computing Radiation Patterns EM.Terrano's Transmitter Set dialog and Receiver Set dialog both allow you to rotate an imported radiation pattern. In SBR ===that case, you need to specify the '''Rotation''' angles in degrees about the X-, Y- and Z-axes. It is important to note that these rotations are performed sequentially and in the following order: first a rotation about the X-axis, then a rotation about the Y-axis, and finally a rotation about the Z-axis. In addition, all the rotations are performed with respect to the "rotated" local coordinate systems (LCS). In other words, the first rotation with respect to the local X-axis transforms the XYZ LCS to a new primed X^&prime;Y^&prime;Z^&prime; LCS. The second rotation is performed with respect to the new Y^&prime;-axis and transforms the X^&prime;Y^&prime;Z^&prime; LCS to a new double-primed X^{&prime;&prime;}Y^{&prime;&prime;}Z^{&prime;&prime;} LCS. The third rotation is finally performed with respect to the new Z^{&prime;&prime;}-axis. The figures below shows single and double rotations.

Coming Soon<table><tr><td> [[File:PROP22B.png|thumb|300px|The local coordinate system of a linear dipole antenna.]] </td><td> [[File:PROP22C.png|thumb|600px|Rotating the dipole antenna by +90&deg; about the local Y-axis.]] </td></tr></table><table><tr><td> [[File:PROP22D.png|thumb|720px|Rotating the dipole antenna by +90&deg; about the local X-axis and then by -45&deg; by the local Y-axis.]] </td></tr></table>

== Scene Discretization &amp; = Adjustment of Tx/Rx Elevation above a Terrain Surface ===

=== When your transmitters or receivers are located above a flat terrain like the global ground, their Z-coordinates are equal to their height above the ground, as the terrain elevation is fixed and equal to zero everywhere. In many propagation modeling problems, your transmitters and receivers may be located above an irregular terrain with varying elevation across the scene. In that case, you may want to place your transmitters or receivers at a certain height above the underlying ground. The Need For Discretization Of Propagation Scene ===Z-coordinate of a transmitter or receiver is now the sum of the terrain elevation at the base point and the specified height. EM.Terrano gives you the option to adjust the transmitter and receiver sets to the terrain elevation. This is done for individual transmitter sets and individual receiver sets. At the top of the Transmitter Dialog there is a check box labeled &quot;'''Adjust Tx Sets to Terrain Elevation'''&quot;. Similarly, at the top of the Receiver Dialog there is a check box labeled &quot;'''Adjust Rx Sets to Terrain Elevation'''&quot;. These boxes are unchecked by default. As a result, your transmitter sets or receiver sets coincide with their associated base points in the project workspace. If you check these boxes and place a transmitter set or a receiver set above an irregular terrain, the transmitters or receivers are elevated from the location of their associated base points by the amount of terrain elevation as can be seen in the figure below.

In a typical SBR simulation, a ray is traced from the location To better understand why there are two separate sets of points in the source until it hits a scatterer. The [[SBR Method|SBR method]] assumes scene, note that the ray hits either a flat facet of the scatterer or one of its edges. In the case of hitting a flat facet, the specular point array (CAD object) is used to launch new reflected and transmitted rayscreate a uniformly spaced base set. The surface of array object always preserves its grid topology as you move it around the facet is treated as an infinite dielectric medium interfacescene. However, at which the reflection transmitters or receivers associated with this point array object are elevated above the irregular terrain and transmission coefficients are calculatedno longer follow a strictly uniform grid. In If you move the case of hitting an edgebase set from its original position to a new location, new diffracted rays are generated in the scene. Howeverbase points' topology will stay intact, only those who reach a nearby receiver in while the associated transmitters or receivers will be redistributed above the terrain based on their line of sight are ever taken into account. In other words, diffractions are treated locallynew elevations.

<table><tr><td> [[EMImage:PROP MAN8.Cube]]'s [[Propagation Module]] allows you to draw any type of surface or solid CAD objects under impenetrable png|thumb|left|640px|A transmitter (red) and penetrable surface groups. Some of these objects have flat faces such as boxes, pyramids, rectangle or triangle strips, etc. Some others contain curved surfaces or curved boundaries such as cylinders, cones, etc. All the non-flat surfaces have to be discretized in the form of a collection grid of smaller flat facets. [[EM.Cube]] uses receivers (yellow) adjusted above a triangular plateau terrain surface mesh generator to discretize . The underlying base point sets (blue and orange dots) associated with the penetrable adjusted transmitters and impenetrable [[Surface Objects|surface objects]] of your propagation scene. This mesh generator is very similar to receivers on the ones used terrain are also visible in [[EMthe figure.Cube]]'s two other modules: MoM3D and Physical Optics (PO). </td></tr></table>

You can build a variety of surface and [[Solid Objects|solid objects]] using [[== Discretizing the Propagation Scene in EM.Cube]]'s native &quot;Curve&quot; CAD objects like lines, polylines, circles, etc. You can use tools like Extrude, Loft, Strip-Sweep, Pipe-Sweep, etc. to transform curves into surface or [[Solid Objects|solid objects]]. '''However, keep in mind that all the &quot;Curve&quot; CAD objects are ignored by the SBR mesh generator and are therefore not sent to the simulation engine.'''Terrano ==

=== Viewing SBR Mesh Why Do You Need to Discretize the Scene? ===

You can view and examine EM.Terrano's SBR solver uses a method known as Geometrical Optics (GO) in conjunction with the discretized version Uniform Theory of your scene objects as they are sent Diffraction (UTD) to trace the SBR simulation engine. To view rays from their originating point at the mesh, click source to the '''Mesh''' [[File:mesh_toolindividual receiver locations.png]] button of the Simulate Toolbar or select '''Simulate &gt; Discretization &gt; Show Mesh'''Rays may hit obstructing objects on their way and get reflected, diffracted or use the keyboard shortcut '''Ctrl+M'''transmitted. A triangular surface mesh of your physical structure appears in the project workspace. In this case, [[EM.Cube]] enters it mesh view mode. You Terrano's SBR solver can perform view operations like rotate view, pan, zoom, etc. But you cannot select objects, or move them or edit their properties. To get out of the Mesh View only handle diffraction off linear edges and return to [[EMreflection from and transmission through planar interfaces.Cube]]'s Normal View, press When an incident ray hits the '''Esc Key''' surface of the keyboardobstructing object, or click a local planar surface assumption is made at the Mesh button specular point. The assumptions of linear edges and planar facets obviously work in the Simulate Toolbar once again, or go to the Simulate Menu case of a scene with cubic buildings and deselect the '''Discretization &gt;''' '''Show Mesh''' itema flat global ground.

You can adjust the mesh resolution and increase the geometric fidelity of discretization by creating more and finer triangular facets. On the other handIn many practical scenarios, however, you may want to reduce the mesh complexity and send to the SBR engine only a few coarse facets to model your buildings. To adjust the mesh resolutionmay have curved surfaces, open or the Mesh Settings Dialog by clicking the '''Mesh Settings''' [[File:mesh_settingsterrain may be irregular.png]] button EM.Terrano allows you to draw any type of the Simulate Toolbar surface or select '''Simulate &gt; Discretization &gt;''' '''Mesh Settingssolid geometric objects such as cylinders, cones, etc.under impenetrable and penetrable surface groups or penetrable volumes.EM.Terrano'''. This dialog provides s mesh generator creates a single [[parameters]]: '''Edge Length'''.triangular surface mesh of all the objects in your propagation scene, which has is called a default value of 100 project unitsfacet mesh. If you are already in Even the Mesh View Mode and open the Mesh Settings Dialog, you can see the effect walls of changing the edge length cubic buildings are meshed using the '''Apply''' buttontriangular cells. Click OK This enables EM.Terrano to close the dialogproperly discretize composite buildings made of conjoined cubic objects.

Note that unlike Unlike [[EM.Cube]]'s other computational modules that express the default mesh density based on the wavelength, the density or resolution of the SBR EM.Terrano's surface mesh generator does not depend on the operating frequency and is not expressed in project length unitsterms of the wavelength. The default edge length value sole purpose of 100 units might be too large for non-flat objectsEM. You may have Terrano's facet mesh is to use discretize curved and irregular scatterers into flat facets and linear edges. Therefore, geometrical fidelity is the only criterion for the quality of a lower value facet mesh. It is important to capture note that discretizing smooth objects using a triangular surface mesh typically creates a large number of small edges among the curvature facets that are simply mesh artifacts and should not be considered as diffracting edges. For example, each rectangular face of your curved structures adequatelya cubic building is subdivided into four triangles along the two diagonals. The four internal edges lying inside the face are obviously not diffracting edges. A lot of subtleties like these must be taken into account by the SBR solver to run accurate and computationally efficient simulations.

Figure 1: [[Propagation Module]]You can view and examine the discretized version of your scene's objects as they are sent to the SBR simulation engine. You can adjust the mesh resolution and increase the geometric fidelity of discretization by creating more and finer triangular facets. On the other hand, you may want to reduce the mesh complexity and send to the SBR engine only a few coarse facets to model your buildings. The resolution of EM.Terrano's facet mesh generator is controlled by the '''Cell Edge Length''' parameter, which is expressed in project length units. The default mesh cell size of 100 units might be too large for non-flat objects. You may have to set a smaller cell edge length in EM.Terrano's Mesh Settings dialog, along with a lower curvature angle tolerance value to capture the curvature of your curved structures adequately.

In [[EMImage:Info_icon.Cube]], terrain objects are represented by and saved as special &quot;Tessellated&quot; objects with quadrilateral cells. This is true of terrain objects that you create yourself using [[EM.Cubepng|30px]]Click here to learn more about '''s Terrain Generator as well as all the terrain objects that you import from external files to your project. The center of each cell represents the terrain elevation at that point. Tessellated objects are considered as discretized objects by [[EMPreparing_Physical_Structures_for_Electromagnetic_Simulation#Working_with_EM.Cube]] and they are not meshed one more time by the SBR mesh generator. Each quadrilateral cell is divided into two triangular cells before being passed to the SBR simulation engine. Therefore, when using [[EM.Cube27s_Mesh_Generators | Working with Mesh Generator]]'s Terrain Generator to create a new terrain object, you have to pay special attention to the resolution of the terrain object as it determines the total number of terrain facets sent to the simulation engine. A high resolution terrain, although looking better and more realistic, may easily lead to an enormous computational problem''.

You can use [[EMImage:Info_icon.Cubepng|30px]]'s &quot;Polymesh&quot; tool Click here to discretize solid and surface CAD objects. You can manually control learn more about the mesh characteristics properties of polymesh objects including inserting new nodes on faces and edges or deleting existing nodes. In addition, '''[[Glossary_of_EM.Cube%27s_Simulation-Related_Operations#Facet_Mesh | EM.Cube]]Terrano's Solid Facet Mesh Generator and Surface Generator tools create ploymesh solids and surfaces, respectively. Like tessellated object, polymesh objects are also considered as discretized objects by [[EM.Cube]] and they are not meshed again by the SBR mesh generator'''.

Coming Soon..== Running Ray Tracing Simulations in EM.Terrano ==

In [[EM.Cube]], buildings and all other CAD objects are initially created on the XY plane by default. In other words, the Z* 3D Field Solver* SBR Channel Analyzer* Log-coordinate of the local coordinate system (LCS) of all blocks is set to zero until you change them. As long as you use the global ground, all is fine as your buildings are seated on the ground. When your propagation scene has an irregular terrain, you want to place your buildings on the terrain and not buried under it. Buildings in [[EM.Cube]] are not adjusted to the terrain elevation automatically. You need to instruct [[EM.Cube]] to do so.Haul Channel Analyzer* Communication Link Solver* Radar Link Solver

To update the building positions and adjust their elevation to the underlying terrain, right click on the '''Terrain''' item of the Navigation Tree and select '''Adjust Scene Elevation''' from the context menu. All the blocks in the scene The first three simulation types are automatically elevated in the Z direction such that their bases sit on the terraindescribed below. In effect, all the blocks are translated along the global Z axis by proper amounts such that their local Z coordinate equals the Z-elevation For a description of the underlying terrain objectEM. This feature is particularly useful if you change the location of the terrain or import a new terrain after the blocks have been createdTerrano's Radar Simulator, follow this link.

Note: You have to make sure that the resolution of your terrain, its fluctuation scale and building dimensions are all comparable. Otherwise, on === Running a highSingle-resolution, rapidly varying terrain, you will have buildings whose bottoms are in contact with the terrain only at a few points and parts of them hang in the air.Frequency SBR Analysis ===

[[File:prop_adjust1_tnIts main solver is the '''3D SBR Ray Tracer'''.png|400px]] [[File:prop_adjust2_tnOnce you have set up your propagation scene in EM.png|400px]]Terrano and have defined sources/transmitters and observables/receivers for your scene, you are ready to run a SBR ray tracing simulation. You set the simulation mode in EM.Terrano's simulation run dialog. A single-frequency SBR analysis is a single-run simulation and the simplest type of ray tracing simulation in EM.Terrano. It involves the following steps:

Figure: A Scene with Buildings * Set the units of your project and Terrain Before the frequency of operation. Note that the default project unit is '''millimeter'''. Wireless propagation problems usually require meter, mile or kilometer as the project unit.* Create the blocks and After Adjusting Elevationdraw the buildings at the desired locations.* Keep the default ray domain and accept the default global ground or change its material properties.* Define an excitation source and observables for your project.* If you intend to use transmitters and receivers in your scene, first define the required base sets and then define the transmitter and receiver sets based on them.* Run the SBR simulation engine.* Visualize the coverage map and plot other data.

=== Transmitters You can access EM.Terrano's Simulation Run dialog by clicking the '''Run''' [[File:run_icon.png]] button of the '''Simulate Toolbar''' or by selecting '''Simulate &amprarr; Receivers Above An Irregular Terrain ===Run...''' or using the keyboard shortcut {{key|Ctrl+R}}. When you click the {{key|Run}} button, a new window opens up that reports the different stages of the SBR simulation and indicates the progress of each stage. After the SBR simulation is successfully completed, a message pops up and prompts the completion of the process.

In <table><tr><td> [[Image:Terrano L1 Fig16.png|thumb|left|480px|EM.CubeTerrano's simulation run dialog.]], all the transmitters and receivers are tied up with point objects in the project workspace. These point objects are grouped and organized in base sets. When you move the point objects or change their coordinates, all of their associated transmitters or receivers immediately follow them to the new location. For example, you usually define a grid of receivers using a base set that is made up of a uniformly spaced array of points and spread them in your scene. All of these receivers have the same height because their associated base points all have the same Z-coordinate. When your receivers are located above a flat terrain like the global ground, their Z-coordinates are equal to their height above the ground, as the terrain elevation is fixed and equal to zero everywhere. The same is true for transmitters, too. </td></tr></table>

In many propagation modeling problems, your transmitters and receivers may be located above an irregular terrain with varying elevation across the scene. In that case, you may want to place your transmitters or receivers at a certain height above the underlying ground. The Z-coordinate of a transmitter or receiver is now the sum of the terrain elevation at the base point and the specified height. <table><tr><td> [[Image:PROP MAN10.png|thumb|left|550px|EM.CubeTerrano's output message window.]] gives you the option to adjust the transmitter and receiver sets to the terrain elevation. This is done for individual transmitter sets and individual receiver sets. At the top of the Transmitter Dialog there is a check box labeled &quot;'''Adjust Tx Sets to Terrain Elevation'''&quot;. Similarly, at the top of the Receiver Dialog there is a check box labeled &quot;'''Adjust Rx Sets to Terrain Elevation'''&quot;. These boxes are unchecked by default. As a result, your transmitter sets or receiver sets coincide with their associated base points in the project workspace. If you check these boxes and place a transmitter set or a receiver set above an irregular terrain, the transmitters or receivers are elevated from the location of their associated base points by the amount of terrain elevation as can be seen in the figure below. </td></tr></table>

To better understand why there are two separate sets of points in === Changing the scene, note that a point array (CAD object) is used to create a uniformly spaced base set. The array object always preserves its grid topology as you move it around the scene. However, the transmitters or receivers associated with this point array object are elevated above the irregular terrain and no longer follow a strictly uniform grid. If you move the base set from its original position to a new location, the base points' topology will stay intact, while the associated transmitters or receivers will be redistributed above the terrain based on their new elevations.SBR Engine Settings ===

[[File:prop_txrx1_tnThere are a number of SBR simulation settings that can be accessed and changed from the Ray Tracing Engine Settings Dialog.pngTo open this dialog, click the button labeled {{key|400px]] [[File:prop_txrx2_tnSettings}} on the right side of the '''Select Simulation or Solver Type''' drop-down list in the Run Dialog. EM.Terrano's SBR simulation engine allows you to separate the physical effects that are calculated during a ray tracing process. You can selectively enable or disable '''Reflection/Transmission''' and '''Edge Diffraction''' in the "Ray-Block Interactions" section of this dialog. By default, ray reflection and transmission and edge diffraction effects are enabled. Separating these effects sometimes help you better analyze your propagation scene and understand the impact of various blocks in the scene.png|400px]]

FigureEM.Terrano allows a finite number of ray bounces for each original ray emanating from a transmitter. This is very important in situations that may involve resonance effects where rays get trapped among multiple surfaces and may bounce back and forth indefinitely. This is set using the box labeled &quot;'''Max No. Ray Bounces'''&quot;, which has a default value of 10. Note that the maximum number of ray bounces directly affects the computation time as well as the size of output simulation data files. This can become critical for indoor propagation scenes, where most of the rays undergo a large number of reflections. Two other parameters control the diffraction computations: Transmitters '''Max Wedge Angle''' in degrees and receivers adjusted above an uneven terrain '''Min Edge Length''' in project units. The maximum wedge angle is the angle between two conjoined facets that is considered to make them almost flat or coplanar with no diffraction effect. The default value of the maximum wedge angle is 170&deg;. The minimum edge length is size of the common edge between two conjoined facets that is considered as a mesh artifact and their associated base setsnot a real diffracting edge. The default value of the minimum edge length is one project units.

== Running A <table><tr><td> [[Image:PROP MAN11.png|thumb|left|720px|EM.Terrano's SBR Simulation ==simulation engine settings dialog.]] </td></tr></table>

[[EMAs rays travel in the scene and bounce from surfaces, they lose their power, and their amplitudes gradually diminish.Cube]]From a practical point of view, only rays that have power levels above the receiver sensitivity can be effectively received. Therefore, all the rays whose power levels fall below a specified power threshold are discarded. The 's [[Propagation Module]] offers three types ''Ray Power Threshold''' is specified in dBm and has a default value of ray tracing simulations:-150dBm. Keep in mind that the value of this threshold directly affects the accuracy of the simulation results as well as the size of the output data file.

An SBR analysis is EM.Terrano gives a few more options for the simplest ray tracing simulation and involves solution of your propagation problem. For instance, it allows you to exclude the following steps:direct line-of-sight (LOS) rays from the final solution. There is a check box for this purpose labeled "Exclude direct (LOS) rays from the solution", which is unchecked by default. EM.Terrano also allows you to superpose the received rays incoherently. In that case, the powers of individual ray are simply added to compute that total received power. This option in the check box labeled "Superpose rays incoherently" is disabled by default, too.

# Set At the unit end of project scene and a ray tracing simulation, the frequency electric field of operationeach individual ray is computed and reported. Note that [[EM.Cube]]'s By default project unit is millimeter. When working with the [[Propagation Module]], pay attention to the project unit. Radio propagation problems usually require meteractual received ray fields are reported, mile or kilometer as which are independent of the project unit.# Create radiation pattern of the blocks and draw the buildings at the desired locationsreceive antennas.# Keep the default EM.Terrano provides a check box labeled "Normalize ray domain and accept the 's E-field based on receiver pattern", which is unchecked by default global ground or change its material properties.# Define If this box is checked, the base sets (at least one for the transmitter and one for field of each ray is normalized so as to reflect that effect of the receiver).# Define the transmitter and receiver(antenna's) using the available base setsradiation pattern.# Run The received power of each ray is calculated from the SBR simulation engine.# Visualize the coverage map and plot other data.following equation:

[[File:PROP12It can be seen that if the ray's E-field is not normalized, the computed ray power will correspond to that of a polarization matched isotropic receiver.png]]

=== In a 3D SBR Simulation Parameters ===simulation, a transmitter shoots a large number of rays in all directions. The electric fields of these rays are polarimetric and their strength and polarization are determined by the designated radiation pattern of the transmit antenna. The rays travel in the propagation scene and bounce from the ground and buildings or other scatterers or get diffracted at the building edges until they reach the location of the receivers. Each individual ray has its own vectorial electric field and power. The electric fields of the received rays are then superposed coherently and polarimetrically to compute the total field at the receiver locations. The designated radiation pattern of the receivers is then used to compute the total received power by each individual receiver.

There are From a number theoretical point of SBR simulation settings that view, the radiation patterns of the transmit and receive antennas are independent of the propagation channel characteristics. For the given locations of the point transmitters and receivers, one can be accessed assume ideal isotropic radiators at these points and changed from compute the polarimetric transfer function matrix of the propagation channel. This matrix relates the received electric field at each receiver location to the SBR Settings Dialogtransmitted electric field at each transmitter location. To open this dialogIn general, click the button labeled vectorial electric field of each individual ray is expressed in the local standard spherical coordinate system at the transmitter and receiver locations. In other words, the polarimetric channel matrix expresses the '''SettingsE_&theta;''' on the right side of the and '''Select EngineE_&phi;''' dropdown list in field components associated with each ray at the Run Dialog. [[EM.Cube]]'s SBR simulation engine allows you receiver location to separate the physical effects that are calculated during a ray tracing process. You can selectively enable or disable its '''Ray Reflection''', '''Ray TransmissionE_&theta;''' and '''Ray DiffractionE_&phi;'''. By default, all three effects are checked and included in field components at the computationstransmitter location. Separating these effects sometimes help you better analyze your propagation scene Each ray has a delay and understand &theta; and &phi; angles of departure at the impact transmitter location and &theta; and &phi; angles of various blocks in departure at the scenereceiver location.

[[EM.Cube]] requires To perform a finite number polarimatric channel characterization of ray bounces for each original ray emanating from a transmitteryour propagation scene, open EM. This is very important in situations that may involve resonance effects where rays get trapped among certain group of surfaces Terrano's Run Simulation dialog and may bounce back and forth indefinitely. This is set using select '''Channel Analyzer''' from the box drop-down list labeled &quot;'''Max No. Ray BouncesSelect Simulation or Solver Type'''&quot;, which has a default value of 10. Note that At the maximum number end of ray bounces directly affects the computation time as well as the size of output simulation , a large ray database is generated with two data filescalled "sbr_channel_matrix. This can become critical for indoor propagation scenesDAT" and "sbr_ray_path.DAT". The former file contains the delay, where most angles of arrival and departure and complex-valued elements of the channel matrix for all the individual rays undergo a large number that leave each transmitter and arrive at each receiver. The latter file contains the geometric aspects of reflectionseach ray such as hit point coordinates.

As rays travel in the scene and bounce from surfaces, they lose their power and their amplitudes diminish. From a practical point of view, only rays that have power above the receiver sensitivity threshold can be effectively received. Therefore, all the rays whose power fall below a specified power threshold are discarded. === The '''Ray Power Threshold''' is specified in dBm and has a default value of "Near Real-100dBm. Keep in mind that the value of this threshold directly affects the accuracy of the simulation results as well as the size of the output data file.Time" Polarimatrix Solver ===

You After EM.Terrano's channel analyzer generates a ray database that characterizes your propagation channel polarimetrically for all the combinations of transmitter and receiver locations, a ray tracing solution of the propagation problem can also set readily be found in almost real time by incorporating the effects of the radiation patterns of transmit and receive antennas. This is done using the '''Angular ResolutionPolarimatrix Solver''' , which is the third option of the transmitter rays drop-down list labeled '''Select Simulation or Solver Type''' in degreesEM. By default, every transmitter emanates equi-angular ray tubes at a resolution of 1 degreeTerrano's Run Simulation dialog. Lower angular resolutions larger than 1° speed up The results of the Polarimatrix and 3D SBR simulation significantly, but they may compromise the accuracy. Higher angular resolutions less than 1° increase the accuracy solvers must be identical from a theoretical point of the simulating resultsview. However, but they also increase there might be small discrepancies between the computation timetwo solutions due to roundoff errors.

[[File:PROP13Using the Polarimatrix solver can lead to a significant reduction of the total simulation time in sweep simulations that involve a large number of transmitters and receivers.png]]Certain simulation modes of EM.Terrano are intended for the Polarimatrix solver only as will be described in the next section.

Figure 1: [[Propagation Module]]{{Note| In order to use the Polarimatrix solver, you must first generate a ray database of your propagation scene using EM.Terrano's SBR Engine Settings dialogChannel Analyzer.}}

=== The Coverage Map EM.Terrano's Simulation Modes ===

If the associated radiator set is isotropic, so will be the transmitter setEM. By default, an isotropic transmitter has vertical polarization. You can use the '''Polarization''' radio button to select one Terrano provides a number of the two options: '''Vertical''' different simulation modes that involve single or '''Horizontal'''. If the associated radiator set consists of '''Short Dipole''' or '''User Defined''' radiators, it is indicated in the transmitter property dialog. In the case of a short dipole radiator, you can set a value for the dipole current in Amperes. The radiation resistance of a short dipole of length ''dl'' is given bymultiple simulation runs:

:<math> R_r = 80\pi^2 \left( \frac{dl}{\lambda_0} \right)^2 </math>| class="wikitable"|-<!scope="col"| Simulation Mode! scope="col"| Usage! scope="col"| Which Solver?! scope="col"| Frequency ! scope="col"| Restrictions|-| style="width:120px;" | [[#Running a Single-Frequency SBR Analysis | Single-Frequency Analysis]]| style="width:180px;" | Simulates the propagation scene "As Is"| style="width:150px;" | SBR, Channel Analyzer, Polarimatrix, Radar Simulator| style="width:120px;" | Runs at the center frequency fc| style="width:300px;" | None|-| style="width:120px;" | [[FileParametric_Modeling_%26_Simulation_Modes_in_EM.Cube#Running_Frequency_Sweep_Simulations_in_EM.Cube | Frequency Sweep]]| style="width:eqngr6180px;" | Varies the operating frequency of the ray tracer | style="width:150px;" | SBR, Channel Analyzer, Polarimatrix, Radar Simulator| style="width:120px;" | Runs at a specified set of frequency samples| style="width:300px;" | None|-| style="width:120px;" | [[Parametric_Modeling_%26_Simulation_Modes_in_EM.Cube#Running_Parametric_Sweep_Simulations_in_EM.pngCube | Parametric Sweep]]| style="width:180px;" | Varies the value(s) of one or more project variables| style="width:150px;" | SBR| style="width:120px;" | Runs at the center frequency fc| style="width:300px;" | Requires definition of sweep variables, works only with SBR solver as the physical scene may change during the sweep |-| style="width:120px;" | [[#Transmitter_Sweep | Transmitter Sweep]]| style="width:180px;" | Activates two or more transmitters sequentially with only one transmitter broadcasting at each simulation run | style="width:150px;" | Polarimatrix| style="width:120px;" | Runs at the center frequency fc| style="width:300px;" | Requires at least two transmitters in the scene, works only with Polarimatrix solver and requires an existing ray database|->| style="width:120px;" | [[#Rotational_Sweep | Rotational Sweep]]| style="width:180px;" | Rotates the radiation pattern of the transmit antenna(s) sequentially to model beam steering | style="width:150px;" | Polarimatrix| style="width:120px;" | Runs at the center frequency fc| style="width:300px;" | Works only with Polarimatrix solver and requires an existing ray database|-| style="width:120px;" | [[#Mobile_Sweep | Mobile Sweep]]| style="width:180px;" | Considers one pair of active transmitter and receiver at each simulation run to model a mobile communication link| style="width:150px;" | Polarimatrix| style="width:120px;" | Runs at the center frequency fc| style="width:300px;" | Requires the same number of transmitters and receivers, works only with Polarimatrix solver and requires an existing ray database|}

:<math> P_{rad} = \frac{1}{2} R_r |I_0|^2 = 40\pi^2 |I_0|^2 \left( \frac{dl}{\lambda_0} \right)^2 </math><!You set the simulation mode in EM.Terrano's simulation run dialog using the drop-down list labeled '''Simulation Mode'''. A single-[[File:shortdipolefrequency analysis is a single-run simulation.png]]All the other simulation modes in the above list are considered multi-run simulations. In multi->run simulation modes, certain parameters are varied and a collection of simulation data files are generated. At the end of a sweep simulation, you can plot the output parameter results on 2D graphs or you can animate the 3D simulation data from the navigation tree.

For isotropic and user defined radiators you can set the '''Input Power''' and '''Phase''' of a transmitter set in Watts and degrees, respectively{{Note| EM. This can be accessed from the Terrano'''Transmitter Chain''' dialog, which will be described in detail in the next section. The radiation pattern of the associated radiator set is normalized and used in conjunction with the input power value to create a weighted distribution of transmitted rays. In certain cases like hybrid s frequency sweep simulations, you may want to use are very fast because the actual values of the far field to define the transmitter power rather than a normalized radiation pattern. Note that the pattern geometrical optics (.RADray tracing) file contains the value part of total radiated power in its header. In this case, check the box labeled '''&quot;Calculate Power From Radiation Pattern&quot;'''. This simulation is calculated directly from the complex &theta; and &phi; components of the far field data by integrating them over the entire space (4&pi; solid angle). Note that this option is available only when the radiator is of the User Defined type. When this box is checked, the transmitter chain button is grayed out. By default, an isotropic transmitter emanates rays uniformly in all directions at the angular resolution specified by the user. A transmitter with a user defined associated radiator may represent a highly directional radiation pattern with the main beam pointing in a certain direction. You can additionally force and limit the '''Angular Extents''' of rays to a certain solid angle around the transmitter. This is especially useful and computationally efficient when the transmitter is on one side of the scene, and all the scatterers and receivers are on the other side. In this case, there is no need to generate rays in all directions. To limit the angular extents of rays, define the Start and End values for both Theta (&theta;) and Phi (&phi;) angles. The value of the angular resolution of the rays can be changed from the Run Dialog as will be discussed laterfrequency-independent.}}

[[File:prop_run11_tnWhen your propagation scene contains two or more transmitters, whether they all belong to the same transmitter set with the same radiation pattern or to different transmitter sets, EM.png|400px]] [[File:prop_run12_tnTerrano assumes all to be coherent with respect to one another. In other words, synchronous transmitters are always assumed. The rays originating from all these transmitters are superposed coherently and vectorially at each receiver. In a transmitter sweep, on the other hand, EM.Terrano assumes only one transmitter broadcasting at a time. The result of the sweep simulation is a number of received power coverage maps, each corresponding to a transmitter in the scene.png|400px]]

Figure: Received power coverage map: (Left) confetti style, {{Note| EM.Terrano's transmitter sweep works only with the Polarimatrix Solver and (Right) cube stylerequires an existing ray database previously generated using the Channel Analyzer.}}

[[File:prop_run4You can rotate the 3D radiation patterns of both the transmitters and receivers from the property dialog of the parent transmitter set or receiver set. This is done in advance before a SBR simulation starts. You can define one or more of the rotation angles of a transmitter set or a receiver set as sweep variables and perform a parametric sweep simulation. In that case, the entire scene and all of its buildings are discretized at each simulation run and a complete physical SBR ray tracing simulation is carried out. However, we know that the polarimetric characteristics of the propagation channel are independent of the transmitter or receiver antenna patterns or their rotation angles. A rotational sweep allows you to rotate the radiation pattern of the transmitter(s) about one of the three principal axes sequentially. This is equivalent to the steering of the beam of the transmit antenna either mechanically or electronically. The result of the sweep simulation is a number of received power coverage maps, each corresponding to one of the angular samples. To run a rotational sweep, you must specify the rotation angle.png]]

=== The Ray Data Mobile Sweep ===

At the end of In a SBR simulationmobile sweep, each transmitter is paired with a receiver receives a number of raysaccording to their indices in their parent sets. Some receivers may not receive any rays at allAt each simulation run, only one (Tx, Rx) pair is considered to be active in the scene. You can visualize all As a result, the rays received by generated coverage map takes a certain receiver from different meaning implying the active transmitter sequential movement of the scenetransmitter and receiver pair along their corresponding paths. To do thisIn other words, right click the '''Receivers''' item set of point transmitters and the Navigation Tree. From set of point receivers indeed represent the context menu select '''Show Received Rays'''. All the rays received by the currently selected receiver locations of the scene are displayed in the scene. The rays are identified by labels, are ordered by their power a single transmitter and have different colors for better visualization. You can display the rays for only one a single receiver at a different instants of time. The receiver set property dialog has a list of all the individual receivers belonging to It is obvious that set. To display the rays received by another receiver, you have to change the '''Selected Receiver''' in the receiver set's property dialog. If you keep the mouse focus on this dropdown list total number of transmitters and roll your mouse scroll wheel, you can scan the selected total number of receivers and move the rays from one receiver to the next in the listscene must be equal. To remove the visualized rays from the sceneOtherwise, right click the Receivers item of the Navigation Tree again and from the context menu select '''Hide Received Rays'''EM.Terrano will prompt an error message.

[[File:prop_run5_tnEM.pngCube]] provides a '''Mobile Path Wizard''' that facilitates the creation of a transmitter set or a receiver set along a specified path. This path can be an existing nodal curve (polyline or NURBS curve) or an existing line objects. You can also import a sptial Cartesian data file containing the coordinates of the base location points. For more information, refer to [[Glossary_of_EM.Cube%27s_Wizards#Mobile_Path_Wizard |800pxMobile Path Wizard]].

Visualization of received rays at {{Note| EM.Terrano's mobile sweep works only with the location of Polarimatrix Solver and requires an existing ray database previously generated using the selected receiverChannel Analyzer.}}

You can also view the ray [[parameters]] by opening the property dialog of === Investigating Propagation Effects Selectively One at a receiver set. By default, the first receiver of the set is always selected. You can select any other receiver from the drop-down list labeled '''Selected Receiver'''. If you click the button labeled '''Show Ray Data''', a new dialog opens up with a table that contains all the received rays at the selected receiver and their [[parameters]]:Time ===

* Delay is the total time delay that In a typical SBR ray experiences travelling from the transmitter to the receiver after tracing simulation, EM.Terrano includes all the reflectionspropagation effects such as direct (LOS) rays, transmissions ray reflection and diffractions transmission, and is expressed in nanosecondsedge diffractions.* Ray Field is At the end of a SBR simulation, you can visualize the received electric field at power coverage map of your propagation scene, which appears under the receiver location due to a specific ray and is given set item in dBV/mthe navigation tree.* Ray Power is The figure below shows the received power at coverage map of the receiver due to random city scene with a specific ray and is given in dBm.* Angles of Arrival are vertically polarized half-wave dipole transmitter located 10m above the &theta; ground and &phi; angles a large grid of vertically polarized half-wave dipole receivers placed 1.5m above the incoming ray at ground. The legend box shows the local spherical coordinate system limits of the color map between -23dBm as the maximum and -150dB (the default receiversensitivity value) as the minimum.

<table><tr><td> [[Image:UrbanCanyon10.png|thumb|left|640px|The Ray Data Dialog also shows the '''Total Received Power''' in dBm and '''Total Received Field''' in dBV/m due to all the rays received by the receiver. You can sort the rays based on their delay, field, power, etc. To do so, simply click on coverage map of the grey column label in the table to sort the rays in ascending order based on the selected parameterrandom city scene with a dipole transmitter. You can also select any ray by clicking on its '''ID''' and highlighting its row in the ]] </td></tr></table. In that case, the selected rays is highlighted in the Project Workspace and all the other rays become thin (faded).>

Note: The rays are summed Sometime it is helpful to change the scale of the color map to better understand the dynamic range of the coverage map. If you double-click on the legend or right-click on the coverage map's name in the navigation tree and select '''Properties''', the Plot Settings dialog opens up coherently at . Select the '''User-Defined''' item and set the receiverlower and upper bounds of color map as you wish.

<table><tr><td> [[FileImage:prop_run6_tnUrbanCanyon15.png|800pxthumb|left|480px|The plot settings dialog of the coverage map.]] </td></tr></table><table><tr><td> [[Image:UrbanCanyon16.png|thumb|left|640px|The received power coverage map of the random city scene with a user-defined color map scale between -80dBm and -20dBm.]]</td></tr></table>

Figure: Analyzing a selected ray To better understand the various propagation effects, EM.Terrano allows you to enable or disable these effects selectively. This is done from the ray data Ray Tracing Simulation Engine Settings dialogusing the provided check boxes.

Besides visualizing the coverage map and received rays in the <table><tr><td> [[EMImage:UrbanCanyon11.Cubepng|EMthumb|left|640px|The received power coverage map of the random city scene with direct LOS rays only.CUBE]]'s </td></tr><tr><td> [[Propagation Module]], you can also plot the '''Path Loss''' of all the receivers belonging to a receiver set as well as the '''Power Delay Profile''' of individual receiversImage:UrbanCanyon12. To plot these data, go the '''Observables''' section png|thumb|left|640px|The received power coverage map of the Navigation Tree and right click on the '''Receivers''' itemrandom city scene with reflected rays only. From the context menu, select '''Plot Path Loss''' or '''Plot Power Delay Profile''', respectively]] </td></tr><tr><td> [[Image:UrbanCanyon13. png|thumb|left|640px|The path loss data between the active transmitter and all the receivers belonging to a receiver set are plotted on a Cartesian graph. The horizontal axis of this graph represents the index of the receiver. Power Delay Profile is a bar chart that plots the received power coverage map of individual rays received by the currently selected receiver versus their time delay. If there is a line of sight (LOS) between a transmitter and receiver, the LOS ray will have the smallest delay and therefore will appear first in the bar chart. Sometimes you may have several random city scene with diffracted rays arriving at a receiver at the same time, i.e. all with the same delay, but with different power level. These will appear as stacked bars in the chartonly.]] </td></tr></table>

You can also plot the path loss and power delay profile graphs and many others from [[== Working with EM.Cube|EM.CUBE]]Terrano's data manager. You can open data manager by clicking the '''Simulation Data Manager''' [[File:data_manager_icon.png]] button of the '''Compute Toolbar''' or by selecting '''Compute [[File:larrow_tn.png]] Data Manager''' from the menu bar or by right clicking on the '''Data Manager''' item of the Navigation Tree and selecting Open Data Manager... from the contextual menu or by using the keyboard shortcut '''Ctrl+D'''. In the Data manager Dialog, you will see a list of all the data files available for plotting. These include the theta and phi angles of arrival and departure of the selected receiver. You can select any data file by clicking and highlighting its '''ID''' in the table and then clicking the '''Plot''' button.==

=== The Ray Tracing Solvers' Output Simulation Data Files ===

Both the SBR solver and the Polarimatrix solver perform the same type of simulation but in two different ways. The SBR solver discretizes the scene including all the buildings and terrain, shoots a large number of rays from the transmitters and collects the rays at the receivers. The Polarimatrix solver does the same thing using an existing polarimetric ray database that has been previously generated using EM.Terrano's Channel Analyzer. It incorporates the effects of the radiation patterns of the transmit and receive antennas in conjunction with the polarimetric channel characteristics. At the end of an SBR a ray tracing simulation, all the results polarimetric rays emanating from the transmitter(s) or other sources that are written received by the individual receivers are computed, collected, sorted and saved into a main output ASCII data file with files. From the reserved name ray data, the total electric field at the location of SBR_Resultsreceivers as well as the total received power are computed.RTOUTThe individual ray data include the field components of each ray, the ray's elevation and azimuth angles of departure and arrival (departure from the transmitter location and arrival at the receiver location), and time delay of the received ray with respect to the transmitter. This file has If you specify the following format:temperatures, noise figure and transmission line losses in the definition of the receiver sets, the noise power level and signal-to-noise ratio (SNR) at each receiver are also calculated, and so are the E_b/N₀ and bit error rate (BER) for the selected digital modulation scheme.

* Receiver Number* Receiver Base XIn wireless propagation modeling for communication system applications, Y the received power at the receiver location is more important than the field distributions. In order to compute the received power, Z Coordinates* Receiver Heightyou need three pieces of information:

NEW LINE* '''Total Transmitted Power (EIRP)''':This requires knowledge of the baseband signal power, the transmitter chain parameters, the transmission characteristics of the transmission line connecting the transmitter circuit to the transmitting antenna and the radiation characteristics of the transmitting antenna.* '''Channel Path Loss''': This is computed through SBR simulation. * '''Receiver Properties''': This includes the radiation characteristics of the receiving antenna, the transmission characteristics of the transmission line connecting the receiving antenna to the receiver circuit and the receiver chain parameters.

where P_t is the baseband signal power in dBm at the transmitter, G_TC and G_RC are the total transmitter and receiver chain gains in dB, respectively, G_TA and G_RA are the total transmitting and receiving antenna gains in dB, respectively, and PL is the channel path loss in dB. Keep in mind that EM.Terrano is fully polarimetric. The transmitting and receiving antenna characteristics are specified through the imported radiation pattern files, which are part of the definition of the transmitters and receivers. In particular, the polarization mismatch losses are taken into account through the polarimetric SBR ray tracing analysis.  If you specify the noise-related parameters of your receiver set, the signal-to-noise ratios (SNR) is calculated at each receiver location: SNR = P_r - P_n, where P_n is the noise power level in dB. When planning, designing and deploying a communication system between points A and B, the link is considered to be closes and a connection established if the received signal power at the location of the receiver is above the noise power level by a certain threshold. In other words, the SNR at the receiver must be greater than a certain specified minimum SNR level. You specify (SNR)_min ss part of the definition of receiver chain in the Receiver Set dialog. In the "Visualization Options" section of this dialog, you can also check the check box labeled '''Generate Connectivity Map'''. This is a binary-level black-and-white map that displays connected receivers in white and disconnected receivers in black. At the end of an SBR simulation, the computed SNR is displayed in the Receiver Set dialog for the selected receiver. The connectivity map is generated and added to the navigation tree underneath the received power coverage map node.  At the end of an SBR simulation, you can visualize the field maps and receiver power coverage map of your receiver sets. A coverage map shows the total '''Received Power''' by each of the receivers and is visualized as a color-coded intensity plot. Under each receiver set node in the navigation tree, a total of seven field maps together with a received power coverage map are added. The field maps include amplitude and phase plots for the three X, Y, Z field components plus a total electric field plot. To display a field or coverage map, simply click on its entry in the navigation tree. The 3D plot appears in the Main Window overlaid on your propagation scene. A legend box on the right shows the color scale and units (dB). The 3D coverage maps are displayed as horizontal confetti above the receivers. You can change the appearance of the receivers and maps from the property dialog of the receiver set. You can further customize the settings of the 3D field and coverage plots.  <table><tr><td>[[Image:AnnArbor Scene1.png|thumb|left|640px|The downtown Ann Arbor propagation scene.]]</td></tr><tr><td>[[Image:AnnArbor Scene2.png|thumb|left|640px|The electric field distribution map of the Ann Arbor scene with vertical dipole transmitter and receivers.]]</td></tr><tr><td>[[Image:AnnArbor Scene3.png|thumb|left|640px|The received power coverage map of the Ann Arbor scene with vertical dipole transmitter and receivers.]]</td></tr><tr><td>[[Image:AnnArbor Scene4.png|thumb|left| 640px |The connectivity map of the Ann Arbor scene with SNR_min = 3dB with the basic color map option.]]</td></tr><tr><td>[[Image:AnnArbor Scene5.png|thumb|left| 640px |The connectivity map of the Ann Arbor scene with SNR_min = 20dB with the basic color map option.]]</td></tr></table> === Visualizing the Rays in the Scene === At the end of a SBR simulation, each receiver receives a number of rays. Some receivers may not receive any rays at all. You can visualize all the rays received by a certain receiver from the active transmitter of the scene. To do this, right click the '''Receivers''' item of the Navigation Tree. From the context menu select '''Show Received Rays'''. All the rays received by the currently selected receiver of the scene are displayed in the scene. The rays are identified by labels, are ordered by their power and have different colors for better visualization. You can display the rays for only one receiver at a time. The receiver set property dialog has a list of all the individual receivers belonging to that set. To display the rays received by another receiver, you have to change the '''Selected Receiver''' in the receiver set's property dialog. If you keep the mouse focus on this dropdown list and roll your mouse scroll wheel, you can scan the selected receivers and move the rays from one receiver to the next in the list. To remove the visualized rays from the scene, right click the Receivers item of the Navigation Tree again and from the context menu select '''Hide Received Rays'''. You can also view the ray parameters by opening the property dialog of a receiver set. By default, the first receiver of the set is always selected. You can select any other receiver from the drop-down list labeled '''Selected Receiver'''. If you click the button labeled '''Show Ray Data''', a new dialog opens up with a table that contains all the received rays at the selected receiver and their parameters: * Delay is the total time delay that a ray experiences travelling from the transmitter to the receiver after all the reflections, transmissions and diffractions and is expressed in nanoseconds.* Ray NumberField is the received electric field at the receiver location due to a specific ray and is given in dBV/m.* Ray Power is the received power at the receiver due to a specific ray and is given in dBm.* Angles of Arrival are the &theta; and &phi; angles of the incoming ray at the local spherical coordinate system of the receiver. <table><tr><td> [[Image:UrbanCanyon17.png|thumb|left|720px|EM.Terrano's ray data dialog showing a selected ray.]] </td></tr></table> The Ray Data Dialog also shows the '''Total Received Power''' in dBm and '''Total Received Field''' in dBV/m due to all the rays received by the receiver. You can sort the rays based on their delay, field, power, etc. To do so, simply click on the grey column label in the table to sort the rays in ascending order based on the selected parameter. You can also select any ray by clicking on its '''ID''' and highlighting its row in the table. In that case, the selected rays is highlighted in the Project Workspace and all the other rays become thin (faded). {{Note|All the received rays are summed up coherently in a vectorial manner at the receiver location.}} <table><tr><td> [[Image:UrbanCanyon18.png|thumb|left|640px|Visualization of received rays at the location of a selected receiver in the random city scene.]] </td></tr></table> === The Standard Output Data File === At the end of an SBR simulation, EM.Terrano writes a number of ASCII data files to your project folder. The main output data file is called "sbr_results.RTOUT". This file contains all the information about individual receivers and the parameters of each ray that is received by each individual receiver. At the end of an SBR simulation, the results are written into a main output data file with the reserved name of SBR_Results.RTOUT. This file has the following format: Each receiver line has the following information: * Receiver ID* Receiver X, Y, Z coordinates* Total received power in dBm* Total number of received rays Each rays line received by a receiver has the following information: * Ray Index* Delay in nsec

* Delay in nsec* Real(and imaginary parts of the three E<supsub>Vx</supsub>) &amp; Imag(, E^V)* Real(E^H) &amp; Imag(E^H)* Real('''E.e_Ry''') &amp; Imag(''', E.e_Rz''')components* Number of ray hit points * PowerCoordinates of individual hit points

The angles of arrival are the &theta; and &phi; angles of a received ray measured in degrees and are referenced in the local spherical coordinate systems centered at the location of the receiver. The angles of departure for a received ray are the &theta; and &phi; angles of the originating transmitter ray, measured in degrees and referenced in the local spherical coordinate systems centered at the location of the active transmitter, which eventually arrives at the receiver. The total time delay is measured in nanoseconds between t = 0 nsec at the time of launch from the transmitter location till being received at the receiver location. The last four columns show the real and imaginary parts of the received electric fields with vertical and horizontal polarizations, respectively. The complex field values are normalized in a way that when their magnitude is squared, it equals the received ray power. If the active transmitter is an isotropic radiator with either a vertical or horizontal polarization, then the field components corresponding to the other polarization will have zero entries in the output data file.

<table><tr><td> [[FileImage:prop_run8_tn.png|800pxthumb|left|720px|A typical SBR output data file.]]</td></tr></table>

By default, you run a single-frequency simulation The available data files in [[EM.Cube|EM.CUBE]]'s [[Propagation Module]]. You set the operational frequency "2D Data Files" tab of a SBR simulation in the project's '''Frequency Dialog''', which can be accessed in a number of waysData Manger include:

# By clicking the * '''FrequencyPath Loss''' [[File:freq_iconThe channel path loss is defined as PL = P_r - EIRP.png]] button The path loss data are stored in a file called "SBR_receiver_set_name_PATHLOSS.DAT" as a function of the '''Compute Toolbar'''receiver index. The path loss data make sense only if your receiver set has the default isotropic radiator.# By selecting * '''ComputePower Delay Profile''' [[File:larrow_tnThe delays of the individual rays received by the selected receiver with respect to the transmitter are expressed in ns and tabulated together with the power of each ray in the file "SBR_receiver_set_name_DELAY.png]]'''Frequency SettingsDAT"...''' You can plot these data from the Menu BarData Manager as a bar chart called the power delay profile.# Using The bars indeed correspond to the keyboard shortcut difference between the ray power in dBm and the minimum power threshold level in dBm, which makes them a positive quantity. * '''Ctrl+FAngles of Arrival'''.# By double clicking : These are the frequency section (box) Theta and Phi angles of the '''Status Bar'''individual rays received by the selected receiver and saved to the files "SBR_receiver_set_name_ThetaARRIVAL.<br /> ANG" and "SBR_receiver_set_name_PhiARRIVAL.ANG". You can plot them in the Data Manager in polar stem charts.

When you run a frequency or parametric sweep in [[File:prop_freqEM.pngTerrano]] , a tremendous amount of data may be generated. [[File:prop_run10EM.pngTerrano]]only stores the '''Received Power''', '''Path Loss''' and '''SNR''' of the selected receiverin ASCII data files called "PREC_i.DAT", "PL_i.DAT" and "SNR_i.DAT", where is the index of the receiver set in your scene. These quantities are tabulated vs. the sweep variable's samples. You can plot these files in EM.Grid.

(Left) Project[[Image:Info_icon.png|40px]] Click here to learn more about working with data filed and plotting graphs in [[EM.Cube]]'s frequency dialog and (Right) the frequency settings dialog'''[[Defining_Project_Observables_%26_Visualizing_Output_Data#The_Data_Manager | Data Manager]]'''.

You can also select the '''Frequency Sweep''' option in the '''Simulation Mode''' drop-down list of the '''Run Dialog'''<table><tr><td> [[Image:Terrano pathloss. Click the '''Settings...''' button on the right side of this dropdown list to open up the Frequency Settings Dialog. Based on the original values png|thumb|360px|Cartesian graph of the project center frequency and bandwidth, the '''Start Frequency''' and '''End Frequency''' have default valuespath loss. You can also change the '''Number of Samples'''. Once you click the '''Run''' button, ]] </td><td> [[EMImage:Terrano delay.Cubepng|EMthumb|360px|Bar graph of power delay profile.CUBE]] performs a frequency sweep by assigning each of the frequency samples as the current operational frequency and running the SBR simulation engine at that frequency</td></tr><tr><td> [[Image:Terrano ARR phi. All the simulation data at all frequency samples are saved into the output data files including &quot;SBR_results.RTOUT&quot;. After the completion png|thumb|360px|Polar stem graph of a frequency sweep simulation, as many coverage maps as the number Phi angle of frequency samples are generated and added to the Navigation Tree under the Receiver Set's entryarrival. You can click on each of the coverage maps corresponding to each of the frequency samples and visualize it in the project workspace. You can also animate the coverage maps. To do so, right click on the receiver set's name in the Navigation Tree and select ''']] </td><td> [[Animation]]''' from the contextual menuImage:Terrano ARR theta. The coverage maps start to animate by their order on the Navigation Tree. Once the entire list is displayed sequentially, it starts all over again from the beginning png|thumb|360px|Polar stem graph of the listTheta angle of arrival. During the [[animation]], the '''</td></tr><tr><td> [[Animation]] Controls''' dialog appears at the lower right corner of the screenImage:Terrano DEP phi. This dialog has a number png|thumb|360px|Polar stem graph of buttons for pause/resume, step forward/backward, and step to the end/start. The title Phi angle of each coverage map is shown in the box labeled '''Sample''' as it is displayed in the main windowdeparture. You can also change the speed of [[animation]]</td><td> [[Image:Terrano DEP theta. The default frame duration has a value png|thumb|360px|Polar stem graph of 300 (3x100) millisecondsTheta angle of departure. To stop the [[animation]], simply press the keyboard's '''Esc Key'''.</td></tr></table>

Multiple coverage maps on When you designate a "User Defined Antenna Pattern" as the Navigation Tree radiator type of a transmitter set or a receiver set, EM.Terrano copies the imported radiation pattern data file from its original folder to the current project folder. The name of the ".RAD" file is listed under the '''3D Data Files''' tab of the data manager. Sometimes it might be desired to visualize these radiation patterns in your propagation scene at the end actual location of the transmitter or receiver. To do so, you have to define a frequency sweep new '''Radiation Pattern''' observable in the navigation tree. The label of the new observable must be identical to the name of the ".RAD" data file. In addition, the Theta and starting an [[animation]] from Phi angle increments of the new radiation pattern observable (expressed in degrees) must be identical to the Theta and Phi angular resolutions of the imported pattern file. If all these conditions are met, then go to the '''Simulate Menu''' and select the item '''Update All 3D Visualization'''. The contents of the 3D radiation patterns are added to the navigation tree. Click on one of the radiation pattern items in the navigation tree and it will be displayed in the contextual menuscene.

<table><tr><td>[[FileImage:prop_run15_tnUrbanCanyon6.png|thumb|left|640px|The received power coverage map of the random city scene with a highly directional dipole array transmitter.]]</td></tr></table>

By Default, [[AnimationEM.Cube]] controls always visualizes the 3D radiation patterns at the origin of coordinates, i.e. at (0, 0, 0). This is because that radiation pattern data are computed in the standard spherical coordinate system centered at (0, 0, 0). The theta and phi components of the far-zone electric fields are defined with respect to the X, Y and Z axes of this system. When visualizing the 3D radiation pattern data in a propagation scene, it is more intuitive to display the pattern at the location of the transmitter or receiver. The Radiation Pattern dialog allows you to translate the pattern visualization to any arbitrary point in the project workspace. It also allows you to scale up or scale down the pattern visualization with respect to the background scene.

=== Running In the example shown above, the imported pattern data file is called "Dipole_Array1.RAD". Therefore, the label of the radiation pattern observable is chosen to be "Dipole_Array1". The theta and phi angle increments are both 1&deg; in this case. The radiation pattern has been elevated by 10m to be positioned at the location of the transmitter and a Parametric Sweep with SBR ===scaling factor of 0.3 has been used.

<table><tr><td>[[FileImage:prop_run24UrbanCanyon8.png|thumb|300pxleft|EM.CUBE's variable 640px|Setting the pattern parameters in the radiation pattern dialog.]]</td></tr></table><table><tr><td>[[Image:UrbanCanyon7.png|thumb|left|720px|Visualization of the 3D radiation pattern of the directional transmitter in the random city scene.]]</td></tr></table>

[[File:prop_run23There is an important catch to remember here.png|thumb|250px|Dialog When you define a radiation pattern observable for defining your project, EM.Terrano will attempt to compute the overall effective radiation pattern of the entire physical structure. However, in this case, you defined the radiation pattern observable merely for visualization purposes. To stop EM.Terrano from computing the actual radiation pattern of your entire scene, there is a check box in EM.Terrano's Ray Tracer Simulation Engine Settings dialog that is labeled '''Do not compute new variables]]radiation patterns'''. This box is checked by default, which means the actual radiation pattern of your entire scene will not be computed automatically. But you need to remember to uncheck this box if you ever need to compute a new radiation pattern using EM.Terrano's SBR solver as an asymptotic EM solver (see next section).

In <table><tr><td>[[EMImage:UrbanCanyon9.Cubepng|thumb|left|640px|EM.CUBE]], all the CAD object properties as well as certain source, material and mesh [[parameters]] can be assigned as [[variables]]Terrano's Run Simulation dialog. [[Variables]] are defined to control and vary the values of such [[parameters]] either for editing purposes or to run parametric sweep or [[optimization]]. Variable are defined using the '''[[Variables]] Dialog''', which can be accessed in the three ways:</td></tr></table>

# By clicking the '''[[Variables]]''' [[File:variable_icon.png]] button of the '''Compute Toolbar'''.# By selecting '''Compute''' [[File:larrow_tn.png]] '''[[Variables]]...''' from the Menu Bar.# == Using the keyboard shortcut '''Ctrl+B'''EM.Terrano as an Asymptotic Field Solver ==

The [[variables]] dialog is initially emptyLike every other electromagnetic solver, EM. To add a new variable, click the Terrano'''Add''' button to open up the '''Add Variable/Syntax Dialog'''. In this dialog you have to type in a name s SBR ray tracer requires an excitation source and one or more observables for the new variable and choose a typegeneration of simulation data. The default type is '''Uniformly Spaced Samples'''EM. You also need to specify the '''Start''', '''Stop''' Terrano offers several types of sources and '''Step''' values observables for the variablea SBR simulation. In You already learned about the figure below, transmitter set as a variable called &quot;Tx_Height&quot; is defined that varies between 2 source and 10 with equal steps of 2. This means the sample receiver set {2,4,6,8,10}. When you return to the [[variables]] dialog, the syntax of the new variable is shown as 2:10:2an observable. The last number in this syntax is always You can mix and match different source types and observable types depending on the variable step. In this example, this variable is going to be used to control the height requirements of the transmitter in a propagation sceneyour modeling problem.

Next, you have to attach the variable to the CAD object. In this case, the CAD object is the point object that represents the transmitter's radiator. To attach a variable to a CAD object, open the object's property dialog and type The available source types in the name of the variable as the value of a property or parameterEM. In this case, the variable Tx_Height is going to control the Z-Coordinate of the point object. Once the value of the object parameter is replaced by the name of an already defined variable, it is updated with the current value of that variable. In the case of a variable of &quot;Uniformly Spaced Samples&quot; type, the current value is the start value. This value will be incrementally varied during a parametric sweep simulation process. Note that a variable can take a fixed value or a discrete set of values, too. You can always open the [[variables]] dialog and change the value or syntax of any variable. To make a new or modified value effective, click the '''Apply''' button of the [[variables]] dialog. You can test the values by performing a '''Dry Run''' of the selected variable. This runs an [[animation]] of the project workspace as the value of the variable changes and all the related CAD objects Terrano are updated accordingly. Note that you can attach the same variable to more than one CAD object property or to the properties of different objects. You can also define multiple values or syntaxes to the same variable. To do so, open the '''Add Variable/Syntax Dialog''', and instead of typing in a new variable name, choose an existing variable name from the '''Name''' dropdown list. This will add a new value or syntax to the existing syntax(es) of the selected variable. When you return to the [[variables]] dialog, [[variables]] with more than one value or syntax will have a dropdown list in the '''Syntax''' column. You can choose any of these values or syntaxed at any time and make the change effective by clicking the '''Apply''' button.:

{| class="wikitable"|-! scope="col"| Icon! scope="col"| Source Type! scope="col"| Applications! scope="col"| Restrictions|-| style="width:30px;" | [[File:prop_run25transmitter_icon.png]]| style="width:150px;" | [[Glossary of EM.Cube's Materials, Sources, Devices & Other Physical Object Types#Point Transmitter Set | Point Transmitter Set]]| style="width:250px;" | Modeling realsitic antennas & link budget calculations| style="width:250px;" | Requires to be associated with a base location point set|-| style="width:30px;" | [[File:hertz_src_icon.png]]| style="width:150px;" | [[Glossary of EM.Cube's Materials, Sources, Devices & Other Physical Object Types#Hertzian Short Dipole Source | Hertzian Short Dipole]]| style="width:250px;" | Almost omni-directional physical radiator| style="width:250px;" | None, stand-alone source|-| style="width:30px;" | [[File:huyg_src_icon.png]]| style="width:150px;" | [[Glossary of EM.Cube's Materials, Sources, Devices & Other Physical Object Types#Huygens Source | Huygens Source]]| style="width:250px;" | Used for modeling equivalent sources imported from other [[EM.Cube]] modules | style="width:250px;" | None, stand-alone source imported from a Huygens surface data file|}

Replacing Click on each type to learn more about it in the value [[Glossary of a CAD object parameter with a variable nameEM.Cube's Materials, Sources, Devices & Other Physical Object Types]].

To run a parametric sweep, open the '''Run Dialog''' and select the '''Parametric Sweep''' option The available observables types in the '''Simulation Mode''' drop-down list. If you have not defined any [[variablesEM.Terrano]] in the project, the box in the '''are: {| class="wikitable"|-! scope="col"| Icon! scope="col"| Source Type! scope="col"| Applications! scope="col"| Restrictions|-| style="width:30px;" | [[VariablesFile:receiver_icon.png]]''' row before the '''View''' will be red| style="width:150px;" | [[Glossary of EM. You have Cube's Simulation Observables & Graph Types#Point Receiver Set | Point Receiver Set]]| style="width:250px;" | Generating received power coverage maps & link budget calculations| style="width:250px;" | Requires to turn it into green before you can run be associated with a simulation. By clicking the '''View''' button, you can open up the base location point set|-| style="width:30px;" | [[variablesFile:Distr Rx icon.png]] dialog from here. Once you click the '''Run''' button, | style="width:150px;" | [[Glossary of EM.Cube's Simulation Observables & Graph Types#Distributed Receiver Set |EM.CUBEDistributed Receiver Set]] performs | style="width:250px;" | Computing received power at a parametric sweep receiver characterized by incrementally varying the values of all the defined Huygens surface data| style="width:250px;" | None, stand-alone source imported from a Huygens surface data file|-| style="width:30px;" | [[variablesFile:fieldsensor_icon.png]] from their start to stop values at the specified steps and updating all the related CAD objects. After the completion | style="width:150px;" | [[Glossary of a parametric sweep simulation, as many coverage maps as the total number of variable samples are generated and added to the Navigation Tree under the receiver setEM.Cube's entry. You can click on each of the coverage maps Simulation Observables & Graph Types#Near-Field Sensor Observable | Near-Field Sensor]]| style="width:250px;" | Generating electric and visualize it in the project workspace. You can also animate the coverage magnetic field distribution maps sequentially. To do so| style="width:250px;" | None, right click on the receiver set's name in the Navigation Tree and select '''stand-alone observable|-| style="width:30px;" | [[AnimationFile:farfield_icon.png]]| style="width:150px;" | [[Glossary of EM.Cube''' from s Simulation Observables & Graph Types#Far-Field Radiation Pattern Observable | Far-Field Radiation Pattern]]| style="width:250px;" | Computing the contextual menu. To stop effective radiation pattern of a radiator in the presence of a large scattering scene | style="width:250px;" | None, stand-alone observable|-| style="width:30px;" | [[animationFile:huyg_surf_icon.png]], simply press the keyboard| style="width:150px;" | [[Glossary of EM.Cube's '''Esc Key'''Simulation Observables & Graph Types#Huygens Surface Observable | Huygens Surface]]| style="width:250px;" | Collecting tangential field data on a box to be used later as a Huygens source in other [[EM.Cube]] modules| style="width:250px;" | None, stand-alone observable|}

Click on each type to learn more about it in the [[File:prop_run26Glossary of EM.pngCube's Simulation Observables & Graph Types]]. When you define a far-field observable in EM.Terrano, a collection of invisible, isotropic receivers are placed on the surface of a large sphere that encircles your propagation scene and all of its geometric objects. These receivers are placed uniformly on the spherical surface at a spacing that is determined by your specified angular resolutions. In most cases, you need to define angular resolutions of at least 1&deg; or smaller. Note that this is different than the transmitter rays' angular resolution. You may have a large number of transmitted rays but not enough receivers to compute the effective radiation pattern at all azimuth and elevation angles. Also keep in mind that with 1&deg; Theta and Phi angle increments, you will have a total of 181 &times; 361 = 65,341 spherically placed receivers in your scene.

Choosing parametric sweep as the simulation mode in the run dialog. {{Note that one variable has been defined and | Computing radiation patterns using EM.Terrano's SBR solver typically takes much longer computation times than using [[EM.Cube|EM.CUBE]] is ready to run 's other computational modules.}} <table><tr><td> [[Image:SBR pattern.png|thumb|540px|Computed 3D radiation pattern of two vertical short dipole radiators placed 1m apart in the simulationfree space at 1GHz.]] </td></tr></table>

EM.Terrano's coverage maps display the received power at the location of all the receivers. The receivers together from a set/ensemble, which might be uniformly spaced or distributed across the propagation scene or may consist of randomly scattered radiators. Every coverage map shows the '''Mean''' and '''Standard Deviation''' of the scene received power for all the receivers involved. These information are displayed at the end bottom of a parametric sweep where the sweep variable is the transmitter heightcoverage map's legend box and are expressed in dB.

=== Statistical Analysis When you run either a frequency sweep or a parametric sweep simulation in EM.Terrano, you have the option to generate two additional coverage maps: one for the mean of Propagation Scene ===all the individual sample coverage maps and another for their standard deviation. To do so, in the '''Run Dialog''', check the box labeled '''&quot;Create Mean and Standard Deviation received power coverage maps&quot;'''. Note that the mean and standard deviation values displayed on the individual coverage maps correspond to the spatial statistics of the receivers in the scene, while the mean and standard deviation coverage maps show the statistics with respect to the frequency or other sweep variable sets at each point in the site. Also, note that both of the mean and standard deviation coverage maps have their own spatial mean and standard deviation values expressed in dB at the bottom of their legend box.

<table><tr><td> [[EMImage:PROP MAN12.Cubepng|thumb|left|480px|EM.CUBE]]Terrano's coverage maps display simulation run dialog showing frequency sweep as the received power at the location of all the receiverssimulation mode along with statistical analysis. The receivers together from a set]] </ensemble, which might be uniformly spaced or distributed across the propagation scene or may consist of randomly scattered radiators. Every coverage map shows the '''Mean''' and '''Standard Deviation''' of the received power for all the receivers involved. These information are displayed at the bottom of the coverage map's legend box and are expressed in dB.td></tr></table>

In the <table><tr><td> [[Propagation Module]], when you ran a sweep simulation (frequency, transmitter or parametric), you also have the option to generate two additional coverage mapsImage: one for the mean of all the individual sample coverage maps and another for their standard deviationUrbanCanyon4. To do so, in the '''Run Dialog''', check the box labeled '''&quot;Create Mean and Standard Deviation Coverage Maps&quot;'''. Note that the png|thumb|left|640px|The mean and standard deviation values displayed on the individual coverage maps correspond to map at the spatial statistics end of the receivers in the scene, while the mean and standard deviation coverage maps correspond to a frequency, transmitter or variable sets defined for the sweep simulation. Also, note that both of the mean and ]] </td></tr><tr><td> [[Image:UrbanCanyon5.png|thumb|left|640px|The standard deviation coverage maps have their own spatial mean and standard deviation values expressed in dB map at the bottom end of their legend boxa frequency sweep.]] </td></tr></table>

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The standard deviation coverage map at the end of a transmitter sweep[[Image:Tutorial_icon.png|30px]] '''[[EM.Cube#EM.Terrano_Documentation | EM.Terrano Tutorial Gateway]]'''

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