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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-ico.png | link=Building_Geometrical_Constructions_in_CubeCAD]] [[image:fdtd-ico.png | link= An EM.Terrano Primer Tempo]] [[image:static-ico.png | link=EM.Ferma]] [[image:planar-ico.png | link=EM.Picasso]] [[image:metal-ico.png | link=EM.Libera]] [[image:po-ico.png | link=EM.Illumina]]</td><tr></table>[[Image:Tutorial_icon.png|30px]] '''[[EM.Cube#EM.Terrano_Documentation | EM.Terrano Tutorial Gateway]]'''

[[Image:Back_icon.png|30px]] '''[[EM.Cube | Back to EM.Cube Main Page]]'''=== Modeling Wireless Propagation=Product Overview==

Every wireless communication system involves a transmitter that transmits some sort of signal (voice, video, data, etc===EM.), a receiver that receives and detects the transmitted signal, and a channel Terrano 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 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 angles.Nutshell ===

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 toolsEM. The different rays arriving at Terrano is a receiver location create constructive and destructive interference patternsphysics-based, site-specific, wave propagation modeling tool that enables engineers to quickly determine how radio waves propagate in urban, natural or mixed environments. This is known as the multipath effectEM. This together Terrano's simulation engine is equipped with a fully polarimetric, coherent 3D ray tracing solver based on the shadowing effects caused by building obstructions lead to channel fading. The use Shooting-and-Bouncing-Rays (SBR) method, which utilizes geometrical optics (GO) in combination with uniform theory of statistical diffraction (UTD) models for prediction of fading effects is widely popular among communication system designers. These models are either based on measurement data or derived from simplistic analytical frameworks. The statistical models often exhibit considerable errors especially in areas having mixed building sizesedges. In such cases, EM.Terrano lets you analyze and resolve all the rays transmitted from one needs to perform a physics-basedore more signal sources, site-specific analysis which propagate in a real physical channel made up of the propagation environment to accurately identify buildings, terrain and establish other obstructing structures. EM.Terrano finds all the possible signal paths from the transmitter to the rays received by a receiver. This involves an electromagnetic analysis of at a particular location in the scene with all physical site and computes their vectorial field and power levels, time delays, angles of its geometrical arrival and physical detailsdeparture, etc. Using EM.Terrano you can examine the connectivity of a communication link between any two points in a real specific propagation site.

===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 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 Nutshell ===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.

EM[[Image:Info_icon.Terrano is a physics-based, site-specific, wave propagation modeling tool that enables engineers png|30px]] Click here 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 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 learn more signal sources, which propagate in a real physical site made up of buildings, terrain and other obstructing structures. EM.Terrano finds all about the rays received by a receiver at a particular location in the physical site and computes their power levels, time delays, angles '''[[Basic Principles of arrival, etc. Using EM.Terrano you can examine connectivity of a communication link between any two points in a real specific propagation siteSBR Ray Tracing | Basic SBR Theory]]'''.

=== Line-of-Sight vs<table><tr><td> [[Image:Manhattan1. Multipath Propagation Channel ===png|thumb|left|420px|A large urban propagation scene featuring lower Manhattan.]]</td></tr></table>

In a free-space line-of-sight (LOS) communication system, === EM.Terrano as the signal propagates directly from the transmitter to the receiver without encountering any obstacles (scatterers). Free-space line-Propagation Module of-sight channels are ideal scenarios that can typically be used to model aerial or space communication system applicationsEM.Cube ===

Click here to learn more about EM.Terrano is the theory ray tracing '''Propagation Module''' of '''[[EM.Cube]]''', a 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 [[Free-Space Propagation ChannelBuilding_Geometrical_Constructions_in_CubeCAD | CubeCAD]] with all of [[EM.Cube]]'s other computational modules.

With the seamless integration of EM.Terrano with [[Image:multi1_tn.png|thumb|500px|A multipath propagation scene showing all the rays arriving at a particular receiverEM.Cube]]In ground-based 's other modules, you can now model complex antenna systemsin [[EM.Tempo]], the presence of the ground as a very large reflecting surface affects the signal propagation to a large extent[[EM. Along the path from a transmitter to a receiverLibera]], the signal may also encounter many obstacles and scatterers such as buildings, vegetation, etc[[EM. In an urban canyon environment with many buildings of different heights and other scatterersPicasso]] or [[EM.Illumina]], a line of sight between the transmitter and receiver generate antenna radiation patterns that can hardly be established. In such cases, the propagating signals bounce back used to model directional transmitters and forth among receivers at the building surfacestwo ends of your propagation channel. It is these reflected or diffracted signals that are often received and detected by the receiverConversely, you can analyze a propagation scene in EM. Such environments are referred to as “multipath”. The group of Terrano, collect all the rays arriving received at a specific certain receiver location experience different attenuations and different time delays. This gives rise import them as coherent plane wave sources to constructive and destructive interference patterns that cause fast fading[[EM. As a receiver moves locallyTempo]], the receiver power level fluctuates sizably due to these fading effects[[EM.Libera]], [[EM.Picasso]] or [[EM.Illumina]].

Link budget analysis for a multipath channel is a challenging task due to the large size of the computational domains involved[[Image:Info_icon. Typical propagation scenes usually involve length scales on the order of thousands of wavelengths. To calculate the path loss between the transmitter and receiver, one must solve Maxwellpng|30px]] Click here to learn more about 's equations in an extremely large space''[[Getting_Started_with_EM. 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 problemsCube | EM. 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 computational efficiencyCube Modeling Environment]]'''.

=== The Advantages & Limitations of EM.Terrano's SBR Method Solver ===

[[EM.Terrano]] provides 's SBR simulation engine utilizes an asymptotic intelligent ray tracing simulation engine algorithm that is based on a technique known as Shootingthe concept of k-anddimensional trees. A k-Bouncingd tree is a space-Rays (SBR)partitioning data structure for organizing points in a k-dimensional space. In this technique, propagating spherical waves k-d trees are modeled as ray tubes or beams particularly useful for searches that emanate from involve multidimensional search keys such as range searches and nearest neighbor searches. In a sourcetypical large radio propagation scene, travel in space, bounce there might be a large number of rays emanating from obstacles and are collected by the receivertransmitter that may never hit any obstacles. As For example, upward-looking rays propagate away from in an urban propagation scene quickly exit the computational domain. Rays that hit obstacles on their source (transmitter)path, they begin to spread (or diverge) over distance. In on the other wordshand, the cross section or footprint of a ray tube expands as a function of the distance from the source. [[EMgenerate new reflected and transmitted rays.Cube]] uses an accurate equiThe k-angular ray generation scheme to that produces almost identical ray tubes in d tree algorithm traces all directions to satisfy energy these rays systematically in a very fast and power conservation requirementsefficient manner. Another major advantage of k-d trees is the fast processing of multi-transmitters scenes.

When EM.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 three vectorial field components are computed, analyzed and preserved throughout the entire ray hits an obstructing surfacetracing process from the source location to the field observation points. You can visualize the magnitude and phase of all six electric and magnetic field components at any point in the computational domain. In most scenes, the buildings and the ground or terrain can be assumed 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 simple reflection or more transmission coefficient formulas for homogeneous medium interfaces. EM.Terrano calculates the reflection and transmission coefficients of multilayer structures as functions of incident angle, frequency and polarization and uses them at the following phenomena may happen:respective specular points.

# Reflection from 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 locally flat surface# Transmission through the locally flat surface# Uniform Theory of Diffraction (UTD). It is 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 them, a very high operational frequency such that the length scales involved are much larger than the operating wavelength. Under this assumed regime, electromagnetic waves start to behave like optical rays. Virtually all the calculations in SBR are based on far field approximations. In order to maintain a high computational speed for urban propagation problems, EM.Terrano ignores double diffractions. Diffractions from edges give rise to a large number of new secondary rays. The power of diffracted rays drops much faster than reflected rays. In other words, an edge between two conjoined locally flat surfaces-diffracted ray does not diffract again from another edge in EM.Terrano. However, reflected and penetrated rays do get diffracted from edges just as rays emanated directly from the sources do.

<table><tr><td> [[EMImage:Multipath_Rays.Cube]] discretizes png|thumb|left|500px|A multipath urban propagation scene showing 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 rays collected by &quot;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 anglereceiver. ]]</td></tr></table>

A new reflected ray is generated == EM.Terrano Features at the specular point, which starts traveling and bouncing around in the scene. If the obstructing surface is penetrable, a second transmitted ray is generated and added to the scene. If the ray hits the edge of an obstacle, it is diffracted from that edge. This leads to the creation of a cone of new rays, which greatly complicate the computational problem. The Uniform Theory of Diffraction (UTD) is used to calculate the wedge diffraction coefficients at the edges of scattering blocks. Note that reflection, transmission and diffraction coefficients are all dependent on the polarization of the incident plane wave.Glance ==

Click here to learn more about <ul> <li> Buildings/blocks with arbitrary geometries and material properties</li> <li> Buildings/blocks with impenetrable surfaces or penetrable 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, IGES and 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 (DEM) terrain models</li> <li> Python-based random city wizard with randomized building locations, 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 theory principal axes</li> <li> Short Hertzian dipole sources with arbitrary orientation</li> <li> Isotropic receivers or receiver grids for wireless coverage modeling</li> <li> Radiator sets with 3D directional antenna patterns (imported from other modules or external files)</li> <li> Full three-axis rotation of imported antenna patterns</li> <li> Interchangeable radiator-based definition of transmitters and receivers (networks of [[SBR Method]].transceivers)</li></ul>

=== Pros and Cons of EM.Terrano's SBR Solver Wave Propagation Modeling ===

[[EM.Terrano]]'s <ul> <li> Fully 3D polarimetric and coherent Shoot-and-Bounce-Rays (SBR ) simulation engine utilizes an intelligent </li> <li> GTD/UTD diffraction models for diffraction from building edges and terrain</li> <li> Triangular surface mesh generator for discretization of arbitrary block geometries</li> <li> Super-fast geometrical/optical ray tracing algorithm that is based on the concept of k-dimensional trees. A using advanced k-d tree is a space-partitioning data structure 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 organizing points in a k-dimensional space. k-d trees are particularly useful superheterodyne transmitters and receivers</li> <li> 17 digital modulation waveforms for searches that involve multidimensional search keys such as range searches the calculation of E_b/N₀ and nearest neighbor searches. In a typical large radio Bit error rate (BER)</li> <li> Incredibly fast frequency sweeps of the entire propagation scene, there might be in a large number single SBR simulation run</li> <li> Parametric sweeps 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 handelements like building properties, generate new reflected or radiator heights and transmitted rays. The k-d tree algorithm traces all these rays systematically in a very fast and efficient manner. Another major advantage rotation angles</li> <li> Statistical analysis of kthe propagation scene</li> <li> Polarimetric channel characterization for MIMO analysis</li> <li> "Almost real-d trees is time" Polarimatrix solver using an existing ray database</li> <li> "Almost real-time" transmitter sweep using the fast processing of multiPolarimatrix solver</li> <li> "Almost real-transmitters scenes. Unlike time" rotational sweep for modeling beam steering using the previous versions of the SBR Polarimatrix solver which could handle one transmitter at </li> <li> "Almost real-time" mobile sweep for modeling mobile communications between Tx-Rx pairs along a time and would superpose all mobile path using the resulting rays at the end of the simulation, the new SBR shoots rays from all the transmitters at the same time. Polarimatrix solver</li></ul>

[[EM.Terrano]]'s SBR solver performs fully polarimetric and coherent SBR simulations with arbitrary transmitter antenna patterns. The new engine solves directly for the vectorial field components at the receiver locations 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 === Data Generation &quotamp;field&quot; solver. As a result, you can visualize the magnitude and phase of all six electric and magnetic field components at any point in the computational domain. For power calculations at the receiver location, an isotropic, polarization-matched, receiving antenna is assumed. Visualization ===

In most scenes<ul> <li> Standard output parameters for received power, the buildings path loss, SNR, E_b/N₀ and the ground or terrain can be assumed to be made BER at each individual receiver</li> <li> Graphical visualization of homogeneous materials. These are represented by their electrical properties such as permittivity e propagating rays in the scene</li> <li> Received power coverage maps</li> <li> Link connectivity maps (based on minimum required SNR and BER)</li> <li> Color-coded intensity plots of polarimetric electric conductivity s. More complex scenes may involve a multilayer ground or multilayer building walls. In such casesfield distributions</li> <li> Incoming ray data analysis at each receiver including delay, one can no longer use the simple reflection or transmission coefficient formulas for homogeneous medium interfaces. [[EM.Cube]] calculates the reflection angles of arrival and transmission coefficients departure</li> <li> Cartesian plots of multilayer structures as functions path loss along defined paths</li> <li> Power delay profile of incident angle, frequency the selected receiver</li> <li> Polar stem charts of angles of arrival and polarization and uses them at departure of the respective specular points. selected receiver</li></ul>

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 Diffraction (UTD). It is not == Building a &quot;full-wave&quot; technique, and it does not solve Maxwell's equations directly or numerically. SBR makes a number of assumptions, chief among them, a very high operational frequency such that the length scales involved are much larger than the operating wavelength. Under this assumed regime, electromagnetic waves start to behave like optical rays. Virtually all the calculations Propagation Scene in SBR are based on far field approximationsEM. Terrano ==

In order to maintain a high computational speed for urban propagation problems, [[EM.Cube]]'s SBR solver ignores double diffractions. Recall that diffractions from edges give rise to a large number of new secondary rays. === The power Various Elements 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.a Propagation Scene ===

== Anatomy Of A Propagation Scene ==typical propagation scene in EM.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.

A typical more complicated propagation scene usually contains several buildings, walls, or other kinds of scatterers and wave obstructing objects. You model all of these elements by drawing geometric objects in [[the project workspace or by importing external CAD models. EM.Terrano]] consists does not organize the geometric objects of several elementsyour project workspace by their material composition. At a minimumRather, you need a transmitter (Tx) at some location to launch rays it groups the geometric objects into the scene and blocks based on a receiver (Rx) at another location to receive and collect the incoming common type of interaction with incident rays. A transmitter and a receiver together make the simplest propagation scene, representing a free-space line-of-sight (LOS) channel. A transmitter is one of [[EM.Cube]]'s several source Terrano offer the following types, while a receiver is one of [[EM.Cube]]'s several observable types. A simpler source type is a Hertzian dipole. A simpler observable is a field sensor that is used to compute the electric and magnetic fields on a specified plane.object blocks:

An {| 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.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 propagation scene may involve several buildings (modeled as 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 surfaces) surface and an underlying flat ground uses thin wall approximation for generating transmitted rays, used to model hollow buildings with ray penetration, entry and exit |-| style="width:30px;" | [[File:terrain_group_icon.png]]| style="width:150px;" | [[Glossary of 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 irregular terrain curve objects | style="width:300px;" | Behaves exactly like impenetrable surfacebut can change the elevation of all the buildings and transmitters and receivers located above it|-| style="width:30px;" | [[File:penet_vol_group_icon. An indoor propagation scene may involve several walls (modeled as thin penetrable surfaces)png]]| style="width:150px;" | [[Glossary of EM.Cube's Materials, a ceiling Sources, Devices & Other Physical Object Types#Penetrable Volume | Penetrable Volume]]| style="width:200px;" | Ray reflection, ray diffraction, ray transmission and a floor arranged according 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 certain floor plan. You can volumetric material block, also build mixed scenes involving both impenetrable used for creating individual solid walls and penetrable blocks, possibly along with irregular terrain surfaces. Your sources interior building partitions and observables can be placed anywhere panels in the sceneindoor scenes|-| style="width:30px;" | [[File:base_group_icon. Your png]]| 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 can be placed outdoors or indoors|-| style="width:30px;" | [[File:scatterer_group_icon. A complete list png]]| style="width:150px;" | [[Glossary of the various elements of a propagation scene is given in the ''EM.Cube's Materials, Sources, Devices & Other Physical Structure''' section Object Types#Point Scatterer Set | Point Scatterer Set]]| style="width:200px;" | Ray reception and ray scattering| style="width:250px;" | Only point, box and sphere objects| style="width:300px;" | Required for the definition of point scatterers as targets in a radar simulation |-| style="width:30px;" | [[Propagation ModuleFile:Virt_group_icon.png]]| style="width:150px;" | [[Glossary of EM.Cube's Navigation Tree as followsMaterials, 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 |}

Impenetrablesurfaces, penetrable and surfaces, terrain surfaces and penetrable volumes represent all the objects that obstruct the propagation of electromagnetic waves (rays) in the free space. What differentiates them is the types of physical phenomena that are used to model their interaction with the impinging rays. Base points are simply used to define transmitter EM.Terrano discretizes geometric objects into a number of flat facets. The field intensity, phase and receiver locations in power of the scenereflected and transmitted rays depend on the material properties of the obstructing facet. The following sections specular surface of this manual will describe each of these elements in detaila facet can be modeled locally as a simple homogeneous dielectric half-space or as a multilayer medium.In that respect, all the obstructing objects such as buildings, walls, terrain, etc. behave in a similar way:

[[Image:PROP14(1)* They terminate an impinging ray and replace it with one or more new rays.png|thumb|250px|The Navigation Tree * They represent a specular interface between two media of EM.Terrano]]different material compositions for calculating the reflection, transmission or diffraction coefficients.

In a SBR simulation, the propagating rays hit the surface of building structures, walls, terrain (or global ground) and bounce back into Sometimes it is helpful to draw graphical objects as visual clues in the scene (reflection)project workspace. Some rays penetrate thin walls or other penetrable surfaces and continue their path on the other side of the surface (transmission)These non-physical objects must belong to a virtual object group. Virtual objects are not discretized by EM. The field intensityTerrano's mesh generator, phase and power of the reflected and transmitted rays depend on they are not passed onto the material properties input data files of the obstructing surfaceSBR simulation engine. 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:

* They terminate an impinging ray <table><tr><td> [[Image:PROP MAN2.png|thumb|left|720px|An urban propagation scene generated by EM.Terrano's "Random City" and replace it with one or more new rays"Basic Link" wizards.* They represent a specular interface between two media It consists of different material compositions for calculating the reflection25 cubic brick buildings, transmission one transmitter and possibly diffraction coefficientsa large two-dimensional array of receivers.]]</td></tr></table>

[[EM.Cube]] has generalized === Organizing the concept of '''Block''' as any object that obstructs and affects radio wave propagation. Rays hit the facets of a block and bounce off the surface of those facets or penetrate them and continue their propagation. Rays also get diffracted off the edges of these blocks. In [[EM.Cube]]'s [[Propagation Module]], blocks are grouped together Scene by the type of their interaction with rays. [[EM.Cube]] currently offers three types of blocks for use in a propagation scene:Block Groups ===

# '''Impenetrable Surfaces:''' Rays hit the facets of this type of blocks and bounce backIn EM.Terrano, but they do not penetrate all the object. It is assumed that geometric objects associated with the interior of such blocks or various scene elements like buildings , terrain surfaces and base location points are highly absorptive.# '''Penetrable Surfaces:''' These grouped together as blocks represent thin surfaces that are used to model the exterior and interior walls of buildings based on their common type. All the &quot;Thin Wall Approximation&quot;objects listed under a particular group in the navigation tree share the same color, texture and material properties. Rays reflect off Once a new block group has been created in the navigation tree, it becomes the surface "Active" group of penetrable surfaces and diffract off their edgesthe project workspace, which is always displayed in bold letters. They also penetrate such thin surfaces and continue their paths You can draw new objects under the active node. Any block group can be made active by right-clicking on its name in the other side of navigation tree and selecting the wall.# '''Terrain Surfaces:Activate''' These blocks are used to provide one or more impenetrable, ground surfaces for the propagation scene. Rays simply bounce off terrain objects. The global ground acts as a flat super-terrain that covers the bottom item of the entire computational domaincontextual menu.

<table><tr><td> [[Image:PROP MAN1.png|thumb|left|480px|EM.Cube]]Terrano's [[Propagation Modulenavigation tree.]] allows you to define block groups of each of the above three types. 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! scope="col"|Physical Effects! scope="col"|Admissible Object Types|-| Impenetrable Surface| ReflectionIt is recommended that you first create block groups, Diffraction| All Solid &amp; Surface CAD Objects|-| Penetrable Surface| Reflectionand then draw new objects under the active block group. However, if you start a new EM.Terrano project from scratch, Diffractionand start drawing a new object without having previously defined any block groups, Transmission| All Solid &amp; Surface a new default impenetrable surface group is created and added to the navigation tree to hold your new CAD Objects|-| Terrain Surface| Reflection| Tessellated Objects Only|}object. You can always change the properties of a block group later by accessing its property dialog from the contextual menu. You can also delete a block group with all of its objects at any time.

In outdoor propagation scenes such as &quot;Urban Canyons&quot;, you are primarily interested in the wireless coverage in the areas among buildings. You can assume that rays bounce off the exterior walls move any geometric object or a selection of these buildings but do not penetrate them. In other words, you ignore the transmitted rays and assume that they are either absorbed or diffused inside the buildings. This is not an unrealistic assumptionobjects from one block group to another. You can also transfer objects among [[EM.Cube]] offers &quot;Impenetrable Blocks&quot; 's different modules. For example, you often need to model move imported CAD models of terrain or buildings in outdoor propagation scenesfrom CubeCAD to EM. A penetrable block has a color Terrano. To transfer objects, first select them in the project workspace or texture property as well as material properties: permittivity (eselect their names in the navigation tree. Then right-click on them and select <subb>rMove To &rarr; Module Name &rarr; Object Group</subb>) and conductivity (s)from the contextual menu. By defaultFor example, if you want to move a brick building is assumed with selected object to a block group called "Terrain_1" in EM.Terrano, then you have to select the menu item '''Move To &epsilonrarr;_r = 4EM.4 and Terrano &sigmararr; = 0Terrain_1''' as shown in the figure below.001 S/m. Impinging rays are reflected from Note that you can transfer several objects altogether using the facets of impenetrable buildings keyboards's {{key|Ctrl}} or diffracted from their edges{{key|Shift}} keys to make multiple selections.

To define <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 imported terrain model of Mount Whitney shown in EM.Terrano's project workspace under a new impenetrable block terrain group, follow these steps:called "Terrain_1".]]</td></tr></table>

# Right click === Adjustment of Block Elevation on either the '''Impenetrable Underlying Terrain Surfaces''' item of the Navigation Tree and select '''Insert New Block...''' A 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.# 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;_r) 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 [[In EM.Cube]]'s native solid or [[Surface Objects|surface Terrano, buildings and all other geometric objects]] or 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 can import external model files like STEPchange them. Since the global ground is located a z = 0, IGES or STLyour buildings are seated on the ground. You When your propagation scene has an irregular terrain, you would want to place your buildings on the surface of the terrain and not buried under it. This can change be done automatically as part of the properties definition of an impenetrable surfacethe block group. In Open the property dialog of the surface a block group, click on the table that list the properties to select and highlight a row. Then, click check the box labeled '''Add/EditAdjust Block to Terrain Elevation''' button . All the objects belonging to open up that block are automatically elevated in the &quot;Edit Layer&quot; dialogZ direction such that their bases sit on the surface of their underlying terrain. In this dialogeffect, you can change the name LCS of each of these individual objects is translated along the material and its permittivity and electric conductivity. The box labeled &quot;Specify Loss Tangent&quot; is unchecked global Z-axis by default. If you check it, you can specify the '''Loss Tangent''' amount of the material, which, in turn, updates Z-elevation of the value of electric conductivity terrain object at the center frequency location of the project. You can also use [[EM.Cube]]'s Material List, which will be explained laterLCS.

[[File:PROP23{{Note| You have to make sure that the resolution of your terrain, its variation scale and building dimensions are all comparable.png]]Otherwise, on a rapidly varying high-resolution terrain, you will have buildings whose bottoms touch the terrain only at a few points and parts of them hang in the air.}}

Figure: <table><tr><td> [[Propagation Module]]'s &quot;Edit Layer&quot; Image:PROP MAN5.png|thumb|left|480px|The property dialog corresponding to of impenetrable surfacessurface showing the terrain elevation adjustment box checked.]]</td></tr></table>

[[File:PROP15(1)== EM.png|thumb|200px|[[Propagation Module]]Terrano's Penetrable Surface dialog]]Ray Domain & Global Environment ==

A typical indoor propagation scene usually involves an arrangement of walls that represent the interior of === Why Do You Need 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 &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&quot; 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).Finite Computational Domain? ===

To 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 penetrable surface groupobject, follow these steps:the domain box is automatically adjusted and extended to enclose all the objects in the scene.

# Right click on one of To change the '''Penetrable Surfaces''' item in the Navigation Tree and select '''Insert New Block...''' A dialog for setting up the wall properties opens up offering a preloaded material type (Brick) with predefined color and texture.# Specify a name for the surface group and select a color or texture.# The properties of a penetrable surface are identical to those of an impenetrable surfaceray domain settings, plus an additional thickness property.# By default, a brick wall with a thickness of 0.5 units is assumed. You can change the '''Thickness''' of the penetrable surface as well as its '''Permittivity''' &epsilon;_r and '''Electric Conductivity''' &sigma;.# Click the '''OK''' button of the dialog to accept follow the changes and close it.procedure below:

Under a penetrable surface group, you can draw any of * Open the Ray Domain Settings Dialog by clicking the '''Domain''' [[EMFile:image025.Cubejpg]]button of the '''Simulate Toolbar'''s native solid or [[Surface Objects|surface objects]] or you can import external model files like STEP, IGES or STLby selecting '''Menu > Simulate > Computational Domain > Settings. You can change the properties of a penetrable surface group including its default thickness. In the property dialog of the surface group.''', click or by right-clicking on the table that list '''Ray Domain''' item of the properties to select navigation tree and highlight a row. Then, click the selecting '''Add/EditDomain Settings...''' button to open up from the &quot;Edit Layer&quot; dialogcontextual menu, or simply using the keyboard shortcut {{key|Ctrl+A}}. Similar to the case * The size of impenetrable surfaces, from this dialog, you can change the material properties (permittivity and electric conductivity) as well as Ray domain is specified in terms of six '''ThicknessOffset'''parameters along the ±X, which ±Y and ±Z directions. The default value of all these six offset parameters is expressed in the 10 project units. Change these values as you like.* You can also use [[EMchange the color of the domain box using the {{key|Color}} button.Cube]]'s Material List* After changing the settings, which will be explained lateruse the {{key|Apply}} button to make the changes effective while the dialog is still open.

<table><tr><td> [[FileImage:PROP25PROP15.png|thumb|left|480px|EM.Terrano's domain settings dialog.]]</td></tr></table>

You can construct several thin walls Most outdoor and arrange them as rooms. A regular room can be built by placing four vertical wall objects together with an optional horizontal wall indoor propagation scenes include a flat ground at their bottom, which bounces incident rays back into the top for the ceilingscene. Alternatively, you may use [[EM.Cube]]'s hollow box objects or boxes with one or two capped end(s)Terrano provides a global flat ground at z = 0. '''Keep in mind The global ground indeed acts as an impenetrable surface that all blocks the penetrable surfaces belonging to entire computational domain from the z = 0 plane downward. It is displayed as a group have translucent green plane at z = 0 extending downward. The color of the ground plane is always the same wall thickness, which as the color of the ray domain. The global ground is initially set assumed to 0be made of a homogeneous dielectric material with a specified permittivity &epsilon;_r and electric conductivity &sigma;.5 project units by By default, a rocky ground is assumed with &epsilon;_r = 5 and &sigma; = 0. Also005 S/m. You can remove the global ground, note that solid CAD objects belonging to in which case, you will have a penetrable surface group are treated as air-filled hollow structuresfree space scene.To disable the global ground, open up the "Global Ground Settings" dialog, which can be accessed by right clicking on the ''' The thickness 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 penetrable surfaces is implied your scene. You can also change the material properties of the global ground and not visualized when displaying objects in set new values for the project workspacepermittivity and electric conductivity of the impenetrable, half-space, dielectric medium.

=== Computational Domain 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 &ampdeg; Global Ground ===C, and Volumetric Water Content, Sand Content and Clay Content all as percentage.

The SBR simulation engine requires a finite computational domain. All the stray rays that hit the boundaries of this finite domain 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 {{Note|To model a free-space propagation scene with various elements like buildings, walls, terrain, etc., 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 have to enclose all the objects in the scenedisable EM. 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 ways:Terrano's default global ground.}}

# Click the '''Domain''' <table><tr><td> [[FileImage:image025Global environ.jpg]] button of the Simulation Toolbarpng|thumb|left|720px|EM.# Select the '''Simulate''' &gt; '''Computational Domain''' &gt; ''Terrano's Global Environment Settingsdialog...''' item of the Simulate Menu.]]# Right click on the '''Ray Domain''' item of the Navigation Tree and select '''Domain Settings...'''</td># Use the keyboard shortcut '''Ctrl + A'''.</tr></table>

Figure 1: In EM.Terrano, transmitters and receivers are indeed point radiators used for transmitting and receiving signals at different locations of the 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 "Physical Structure" section of the navigation tree. As radiators, transmitters and receivers are defined by a radiator type with a certain far-field radiation pattern. Consistent with [[Propagation ModuleEM.Cube]]'s Domain Settings dialogother computational modules, transmitters are categorizes as an excitation source, while receivers are categorized as a project observable. In other words, a transmitter is used to generate electromagnetic waves that propagate in the physical scene. A receiver, on the other hand, is used to compute the received fields and received signal power or signal-to-noise ratio (SNR). For this reason, transmitters are defined and listed under the "Sources" sections of the navigation tree, while receivers are defined and listed under the "Observables" section.

Most outdoor and indoor propagation scenes include a flat ground at their bottom, which bounces incident rays back into the scene. [[EM.Cube]]'s [[Propagation Module]] 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 three radiator types for the permittivity and electric conductivity of the impenetrable, half-space, dielectric medium. '''Do not forget to disable the global ground if you want to model a free space propagation scene.'''point transmitter sets:

Figure 2: [[Propagation Module]]'s Global Ground Settings dialogEM.Terrano also provides three radiator types for point receiver sets:

[[File:PROP16The default transmitter and receiver radiator types are both vertical (Z-directed) half-wave dipoles.png|thumb|200px|[[Propagation Module]]'s Terrain dialog]]

A terrain surface acts as There are three different ways to define a custom, unlevel transmitter set or irregular ground for your propagation scene. [[EM.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.receiver set:

Terrain *By defining point objects have some important differences or point arrays under physical base location sets in the navigation tree and then associating them with objects of a transmitter or receiver set*Using Python commands emag_tx, emag_rx, emag_tx_array, emag_rx_array, emag_tx_line and emag_rx_line*Using the &quot;Impenetrable Surface&quot; type:"Basic Link" wizard

# While impenetrable blocks can be created using any of [[EM.Cube]]'s solid or surface CAD object creation tools, terrain objects are created either using [[EM.Cube]]'s '''Terrain Generator''' or by importing an external terrain file. # Terrain objects belong to === Defining a special type of CAD objects called &quot;Tessellated Objects&quot;, 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 Point Transmitter Set in the elevation of other objects or transmitters or receivers that are located above them.Formal Way ===

Just Transmitters act as other blocks are grouped by their color, texture and material composition, terrain objects are also grouped sources in a similar fashionpropagation scene. Before you can generate or import A transmitter is a new terrain object, first you have to define point radiator with a terrain group and specify its color/texture and material propertiesfully polarimetric radiation pattern defined over the entire 3D space in the standard spherical coordinate system. To define EM.Terrano gives you three options for the radiator associated with a new terrain group, follow these stepspoint transmitter:

* Right click on the '''Terrain''' item in the Navigation Tree and select '''Insert New Terrain...''' A dialog for setting up the terrain properties opens up offering a of preloaded material type (Rock) with predefined green color and no texture.Half-wave dipole* Specify a name for the terrain group and select a color or texture.Orthogonally polarized isotropic radiators* Similar to other blocks, you have to specify the material properties, Permittivity (&epsilon;_r) and Electric Conductivity (&sigma;), of the terrain group. Rock with &epsilon;_r = 5 and &sigma; = 0.005 S/m is the default material choice for a new terrain.* Click the '''OK''' button of the dialog to accept the changes and close it.User defined antenna pattern

You can change the properties of a terrain surface group from its property dialogBy default, EM. Click on the table Terrano assumes that list the properties to select and highlight your transmitter is a rowvertically polarized (Z-directed) resonant half-wave dipole antenna. Then, click This antenna has an almost omni-directional radiation pattern in all azimuth directions. It also has radiation nulls along the '''Add/Edit''' button to open up axis of the &quot;Edit Layer&quot; dialog, which is identical to the case of impenetrable surfacesdipole. You can also use [[EM.Cube]]'s Material List, which will be explained later. When a new terrain type is created, its node on change the Navigation Tree becomes active. Under this node you can create direction of the dipole and add new terrain objectsorient it along the X or Y axes using the provided drop-down list. When a terrain node The second choice of two orthogonally polarized isotropic radiators is an abstract source that is active used for drawing, all CAD object creation tools are disabled. You have three options for creating a new terrain object, which polarimetric channel characterization as will be described in detail in the next sections of this manual:discussed later.

# Use 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 [[EM.Cube]]'s '''Terrain Generator'''other computational modules, [[EM.# Import an external terrain Tempo]], [[EM.Picasso]], [[EM.Libera]] or [[EM.Illumina]], and generate a 3D radiation pattern data file of for it. The far-field radiation patter data are stored in a specially formatted file with a &quot;'''.TRNRAD'''&quot; typefile extension.# Import an external terrain This file contains columns of spherical &quotphi;and &theta; angles as well as the real and imaginary parts of the complex-valued far-zone electric field components '''.DEME_&theta;'''and '''E_{&quotphi; type}'''. The &theta;- and &phi;-components of the far-zone electric field determine the polarization of the transmitting radiator.

Click here to learn more about [[Using Terrain Generator]]{{Note|By default, EM.Terrano assumes a vertical half-wave dipole radiator for your point transmitter set.}}

[[File:PROP18A transmitter set always needs to be associated with an existing base location set with one or more point objects in the project workspace.png|thumb|250px|[[Propagation Module]]'s Terrain Generator dialog]]Therefore, you cannot define a transmitter for your scene before drawing a point object under a base location set.

You can import two types of terrain in <table><tr><td> [[EM.Cube]]'s [[Propagation Module]]Image:Terrano L1 Fig11. png|thumb|left|480px|The first type is &quot;'''.TRN&quot;''' terrain file, which is [[EM.Cube]]'s native terrain format. It is a basic digital elevation map with a very simple ASCII data file format. The resolution of the terrain map in the X and Y directions is specified in meters as STEPS. The (x, y, z) coordinates of the terrain points are then listed one point per linetransmitter set definition dialog. The other type of terrain format supported by [[EM.Cube]] is the standard '''7.5min DEM''' file format with a '''.DEM''' file extension. </td></tr></table>

To import an external terrain model, first Once you have to create define a terrain group node new transmitter set, its name is added in the Navigation Tree'''Transmitters''' section of the navigation tree. Right click on The color of all the name base points associated with 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 terrain group in property dialog of the Navigation Tree transmitter set and select either modify a number of parameters including the '''Import Terrain...Source Power''' or in Watts and the broadcast signal '''Import DEM File...Phase''' A standard [[Windows]] in degrees. The default transmitter power level is 1W or 30dBm. There is also a check box labeled '''Open DialogUse Custom Input Power''' opens up, with 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;Total Radiated Power&quot; in their file type set header. This quantity is calculated based on the particular excitation mechanism that was used to generate the pattern file in the original [[EM.TRN or Cube]] module.DEM extensionsWhen the "Use Custom Input Power" check box is unchecked, respectivelyEM. You can browse your folders and find Terrano will use the right terrain model total radiated power value of the radiation file to importfor the SBR simulation.

You can also export all {{Note|In order to modify any of the terrain objects in the project workspace as a terrain file with a transmitter set'''.TRN''' file extension. You can even import a DEM terrain model from an external file and then save and export it as a native terrain (.TRN) file. To export the terrains parameters, first you need to select '''File''' &gt; '''Export...''' from [[Propagation Module]]'s '''File Menu'''. The standard [[Windows]] Save Dialog opens up with the default file type set "User Defined Antenna" option, even if you want to '''.TRN'''. Type in a name for keep the vertical half-wave dipole as your new terrain file and click the '''Save''' button to export the terrain dataradiator.}}

<table><tr><td> [[File:prop_manual-12_tnNewTxProp.png|800pxthumb|left|720px|The property dialog of a point transmitter set.]]</td></tr></table>

Figur: An Your transmitter in EM.Teranno is indeed more sophisticated than a simple radiator. It consists of a basic "Transmitter Chain" that contains a voltage source with a series source resistance, and connected via a segment of transmission line to a transmit antenna, which is used to launch the broadcast signal into the free space. The transmitter's property dialog allows you 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 characteristics of the baseband/IF amplifier, mixer and power amplifier (PA) including stage gains and impedance mismatch factors (IMF) as well as the characteristics of the transmission line segment that connects the PA to the antenna. Note that the transmit antenna characteristics are automatically filled using the contents of the imported external terrain modelradiation pattern data file. The transmitter Chain dialog also calculates and reports the "Total Transmitter Chain Gain" based on your input. When you close this 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.

[[File:PROP26.png|thumb|200px|Propagation Module's Penetrable Surface Dialog showing === Defining a three-layer wall composition]]Point Receiver Set in the Formal Way ===

Most of the time, your outdoor Receivers act as observables in a propagation scene consists of simple buildings made of single-layer walls with standard material properties (&epsilon;_r and &sigma;). In the case The objective of a single-layer impenetrable surface, the specular interface SBR simulation is an infinite dielectric half-space, which reflects to calculate the impinging rays. Singlefar-layer penetrable surfaces, on zone electric fields and the other hand, involve finite-thickness dielectric walls, which both reflect and transmit total received power at the incident rayslocation of a receiver. Similarly, most of your indoor propagation scenes involve simple single-layer penetrable walls with You need to define at least one receiver in the specified material properties &epsilon;_r and &sigma;scene before you can run a SBR simulation. A thin wall acts like Similar to a finite-thickness dielectric slab that both reflects and transmits incident rays. In the case of the global ground or terrain objectstransmitter, only ray reflection off the ground surface a receiver is considereda point radiator, too. EM.Terrano gives you three options for the radiator associated with a point receiver set:

In [[EM.Cube]]'s [[Propagation Module]], you can define multilayer surfaces with both reflection and transmission properties. You can define multilayer impenetrable buildings, multilayer penetrable walls, and multilayer terrain, with an arbitrary number of layers having different material compositions. You define a multilayer surface in the property dialog of a block, whether impenetrable, penetrable or terrain. In the section entitled '''Surface Type''', two options are available: '''Standard Material''' or '''* Half-wave dipole* Polarization matched isotropic radiator* User Defined Model'''. For simple multilayer walls, select the '''Standard Material''' option. You can add new layers with arbitrary thickness and material [[parameters]] to the existing layers. To insert a new layer, deselect any items in the layer list, and click the '''Add/Edit''' button to open the &quot;Add Layer&quot; Dialog. Here you can enter a name for the new layer and values for its '''Thickness''', &epsilon;_r and &sigma;. You may also delete any layer by selecting and highlighting it and clicking the '''Delete''' button. You can move layers up or down using the '''Move Up''' and '''Move Down''' buttons and change the layer hierarchy.defined antenna pattern

By default, EM.Terrano assumes that your receiver is a vertically polarized (Z-directed) resonant half-wave dipole antenna. You can also search [[EM.Cube]]'s material database by clicking change the '''Material''' button direction of &quot;Add Layer&quot; the dipole and orient it along the X or &quot;Edit Layer&quot; dialogs. This opens Y axes using the '''Materials''' Dialogprovided drop-down list. Inside the material list select An isotropic radiator has a perfect omni-directional radiation pattern in all azimuth and highlight any row and click the elevation directions. An isotropic radiator doesn'''OK''' button. The selected material will fill out all the fields t exist physically in the &quot;Add Layer&quot; or &quot;Edit Layer&quot; dialogs. Inside the Materials Dialogreal world, you but it can type the few first letters of any material, and it will take you be used simply as a point in space to compute the corresponding row of the listelectric field.

[[File:PROP24You may also define a complicated radiation pattern for your receiver set.png]]In that case, you need to import a radiation pattern data file to EM.Terrano similar to the case of a transmitter set.

Figure: [[{{Note|By default, EM.Cube]]'s material listTerrano assumes a vertical half-wave dipole radiator for your point receiver set.}}

=== Transferring Objects From Or 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. All the receivers belonging to the same receiver set have the same radiator type. A typical propagation scene contains one or few transmitters but usually a large number of receivers. To Other Modules ===generate a wireless coverage map, you need to define an array of points as your base location set.

When you start a new project in [[EMImage:Info_icon.Cubepng|40px]]'s [[Propagation Module]] and draw a solid object like a box in the project workspace without having defined any surface groups, it is assumed Click here to be of the impenetrable surface type. A default impenetrable surface group called Block_1 is automatically added learn how to the Navigation Tree, which holds your newly drawn object. The default group has the material properties of &quot;Brick&quot; (&epsilon;_r = 4.4 and &sigma; = 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 default, the last surface group that was defined is '''Active'''[[Glossary_of_EM. 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 '''ActivateCube%27s_Simulation_Observables_%26_Graph_Types#Point_Receiver_Set | Point Receiver Set]]''' item of the contextual menu.

You can move any object from its current surface group into any other available surface group. First select 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 <table><tr><td> [[Propagation Module]] to [[EMImage:Terrano L1 Fig12.Cube]]'s other modules or vice versapng|thumb|left|480px|The point receiver set definition dialog. '''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.</td></tr></table>

Like every other electromagnetic solver, <table><tr><td> [[EMFile:NewRxProp.Cube]]'s SBR ray tracer requires png|thumb|left|720px|The property dialog of a source for excitation and one or more observables for generation of simulation datapoint receiver set. [[EM.Cube]]'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:</td></tr></table>

* [[#Defining Transmitter SetsIn the Receiver Set dialog, there is a drop-down list labeled '''Selected Element''', which contains a list of all the individual receivers belonging to the receiver set. At the end of an SBR simulation, the button labeled {{key|Transmitter]]* [[#Hertzian Dipole Sources|Hertzian Dipole]]Show Ray Data}} becomes enabled. Clicking this button opens the Ray Data dialog, where you can see a list of all the received rays at the selected receiver and their computed characteristics.

There If 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. The receiver set's property dialog allows you to define the basic receiver chain. Click the {{key|Receiver Chain}} button of the Receiver Set dialog to open the receiver chain dialog. As shown in the figure below, you can specify the characteristics of the 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. Note that the receiving antenna characteristics are automatically filled from using contents of the radiation file. You have to enter values for antenna's '''Brightness Temperature''' as well as the temperature of the transmission line and the receiver's ambient temperature. The effective '''Receiver Bandwidth''' is assumed to be 100MHz, which you can change for the purpose of noise calculations. The Receive Chain dialog calculates and reports the "Noise Power" and "Total Receiver Chain Gain" based on your input. At the end of an SBR simulation, the receiver power and signal-noise ratio (SNR) of the selected receiver are calculated and they are four types reported in the receiver set dialog in dBm and dB, respectively. You can examine the properties of observables:all the individual receivers and all the individual rays received by each receiver in your receiver set using the "Selected Element" drop-down list.

* <table><tr><td> [[#Defining Receiver SetsFile:NewRxChain.png|Receivers]]* [[#Defining Field Sensorsthumb|left|720px|Field SensorEM.Terrano's point receiver chain dialog.]]</td>* Far Fields</tr>* Huygens Surface</table>

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 === Modulation Waveform 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-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. <br /> Detection ===

[[File:PROP18*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 (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 simplest transmitter type. This release of [[EM.Cube]] has abandoned isotropic radiator transmitters because they do not exist physically in a real world. Instead, the default transmitter radiator type is now a Hertzian dipole. Note that before defining a transmitter, 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 can be made up of a single point for this purposeBT = 0. 3)

To define a new Transmitter SetIn the above list, go you need to specify the '''SourcesNo. Levels (M)''' section of for the Navigation TreeMary modulation schemes, right click on from which the '''TransmittersNo. Bits per Symbol''' item and select '''Insert Transmitteris determined...''' A dialog opens up that contains You can also define a default name bandwidth for the new Transmitter Set as well as signal, which has a dropdown list labeled '''Select Base Set'''default value of 100MHz. In this list you will see all Once the available base sets already defined in SNR of the project workspace. Select the desired base set to associate with the transmitter set. Note that if signal is found, given 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 setspecified modulation scheme, the base points change their color to the transmitter colorE_b/N₀ parameter is determined, from which the bit error rate (BER) is red by defaultcalculated.

In The Shannon – Hartley Equation estimates the &quot;Radiator&quot; section of the dialog, you have two options to choose fromchannel capacity: &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-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.

<math> C === Defining Base Point Sets ===B \log_2 \left( 1 + \frac{S}{N} \right) </math>

[[File:PROP1.png|thumb|[[Propagation Module]]'s Base Set dialog]]In order to tie up transmitters and receivers with CAD objects where B in the project workspacebandwidth in Hz, [[EM.Cube]] uses point objects to define transmitters and receivers. These point objects represent C is the base of the location of transmitters and receivers channel capacity (maximum data rate) expressed 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 elevationbits/s.

To create a new base set, right click on the '''Base Sets''' item The spectral efficiency of Navigation Tree and select '''Insert Base Set...''' A dialog for setting up the Base Set properties opens up.channel is defined as

Once a base set node has been added to the Navigation Tree, 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 The quantity E_b/N₀ is initially drawn on the XY plane. Make sure ratio of energy per bit to change the Z-coordinate of your radiator, otherwise, it will fall on the global ground at z = 0noise power spectral density. You can also create arrays of base points under the same base set. This It is particularly useful for setting up receiver grids to compute coverage maps. Simply select a point object measure of SNR per bit and click is calculated from 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).following equation:

<math> \frac{E_b}{N_0} === Defining Transmitter Sets ===\frac{ 2^\eta - 1}{\eta} </math>

A short dipole is the closest thing to an omni-directional radiator. The direction or orientation 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 where &quoteta;'''.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 the transmitting radiatorspectral efficiency.

To define a directional transmitter radiator, you need to select The relationship between the &quot;User Defined&quot; option in bit error rate and E_b/N₀ depends on the &quot;Radiator&quot; section of the Transmitter Dialogmodulation scheme and detection type (coherent vs. You can do this either at the time of creating a transmitter set, or afterwards by opening the property dialog of the transmitter setnon-coherent). In the &quot;Custom Pattern [[Parameters]]&quot;For example, 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 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. Howevercoherent QPSK modulation, you one 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 orderwrite: first a rotation about the X-axis, then a rotation about the Y-axis, and finally a rotation about the Z-axis.

[[File:PROP19<math> P_b = 0.5 \; \text{erfc} \left(1\sqrt{ \frac{E_b}{N_0} } \right).png]] [[File:PROP20 </math> where P_b is the bit error rate and erfc(1x).png]]is the complementary error function:

Figure <math> \text{erfc}(x) = 1: [[Propagation Module]]'s Transmitter dialog with a user defined radiator selected.-\text{erf}(x) = \frac{2}{\sqrt{\pi}} \int_{x}^{\infty} e^{-t^2} dt </math>

=== Multiple Transmitters vsThe '''Minimum Required SNR''' parameter is used to determine link connectivity between each transmitter and receiver pair. If you check the box labeled '''Generate Connectivity Map''' in the receiver set property dialog, a binary map of the propagation scene is generated by EM.Terrano, in which one color represents a closed link and another represent no connection depending on the selected color map type of the graph. EM.Terrano also calculates the '''Max Permissible BER''' corresponding to the specified minimum required SNR and displays it in the receiver set property dialog. Antenna Arrays ===

[[=== A Note on EM.Cube]]Terrano'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.Native Dipole Radiators ===

If that radiators are indeed the elements of an actual antenna array with When you define a half wavelength spacing new transmitter set or soa new receiver set, we recommend that you import EM.Terrano assigns a vertically polarized half-wave dipole radiator to the set by default. The radiation pattern of the array structure instead and replace the whole multi-radiator system with a single point transmitting radiator in your propagation scene. This case this native dipole radiators is usually encountered in MIMO systems, and calculated using an equivalent point transmitter is an acceptable approximation because the total size of the array aperture is usually much smaller than the dimensions of your propagation scene well-know expressions that are derived based on certain assumptions and its representative length scalesapproximations. In that caseFor example, you need to position the equivalent point radiator at the radiation center far-zone electric field of the a vertically-polarized dipole antenna array. This depends on the physical structure of the antenna array. However, keep in mind that any reasonable guess may still provide a good approximation without any significant error in the received ray data. can be expressed as:

Receivers act as observables in a propagation scene. The objective of a SBR simulation is to calculate the far-zone electric fields and the total received power at the location of a receiver. In that sense<math> E_\phi(\theta, receivers indeed act as field observation points. You need to define at least one receiver in the scene before you can run a SBR simulation. You define the receivers of your scene by associating them with the base sets you have already defined in the project workspace. Unlike transmitters that usually one or few, a typical propagation scene may involve a large number of receivers. To generate a wireless coverage map, you need to define an array of points as your base set. \phi) \approx 0 </math>

To define a new Receiver Set, go to the Observables section of where k₀ = 2&pi;/&lambda;₀ is the Navigation Treefree-space wavenumber, right click on the '''Receivers''' item and select '''Insert Receiver...''' A dialog opens up that contains a default name for the new Receiver Set as well as a dropdown list labeled '''Select Radiator Set'''. In this list you will see all the available base sets that you have already define in the project workspace. Select and designate the desired base set as the receiver set. Note that if the base set contains more than one point, all of them are designated as receivers. After defining a receiver set, the points change their color to the receiver color, which &lambda;₀ is yellow by default. The first element of the set is represented by a larger ball of the same color indicating that it is the selected receiver in the scene. The Receiver Set Dialog is also used to access individual receivers of the set for data visualization at the end of a simulation. At the end of an SBR simulationfree-space wavelength, the button labeled &quoteta;Show Ray Data₀ = 120&quotpi; becomes enabled. Clicking this button opens &Omega; is the Ray Data Dialogfree-space intrinsic impedance, where you can see a list of all I₀ is the received rays at current on the selected receiver dipole, and their computed characteristicsL is the length of the dipole.

[[FileThe directivity of the dipole antenna is given be the expression:PROP21(1).png]] [[File:PROP22.png]]

Figure 1: <math> D_0 \approx \frac{2}{F_1(k_0L) + F_2(k_0L) + F_3(k_0L)} \left[[Propagation Module]\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]'s Receiver dialog.^2 </math>

In the section titled Output Settings, you can also select the field map type from two options: '''Confetti''' and '''Cone'''. The former produces an intensity plot for field amplitude and phase, while the latter generates a 3D vector plot. In the confetti case, you have an option to check the box labeled '''Data Interpolation''', which creates a smooth and blended <math> F_2(digitally filteredx) = \frac{1}{2} \text{sin}(x) \left[ S_i(2x) map. In the cone case, you can set the size of the vector cones that represent the field direction. At the end of a sweep simulation, multiple field map are produced and added to the Navigation Tree. You can animate these maps. However, during the sweep only one field type is stored, either the E-field or H-field. You can choose the field type for multiple plots using the radio buttons in the section titled '''Field Display - Multiple Plots'''. The default choice is the E-field. 2S_i(x) \right] </math>

Once you close the Field Sensor dialog, its name is added under the '''Field Sensors''' node of the Navigation Tree. 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 <math> F_3('''E'''x) and magnetic = \frac{1}{2} \text{cos}('''H'''x) field as well as the total electric and magnetic fields defined in the following manner:\left[ \gamma + \text{ln}(x/2) + C_i(2x) - 2C_i(x) \right] </math>

:where &gamma; = 0.5772 is the Euler-Mascheroni constant, and C<mathsub> \mathbf{|H_{tot}|} = \sqrt{|H_x|^2 + |H_y|^2 + |H_z|^2} i</mathsub>(x) and S<!--[[Filesub>i</sub>(x) are the cosine and sine integrals, respectively:PMOM88.png]]-->

<math> S_i(x) == Scene Discretization &amp; Adjustment ==\int_{0}^{x} \frac{ \text{sin} \tau}{\tau} d\tau </math>

In a typical SBR simulation, a ray is traced from the location case of the source until it hits a scattererhalf-wave dipole, L = &lambda;₀/2, and D₀ = 1. The [[SBR Method|SBR method]] assumes that the ray hits either a flat facet of the scatterer or one of its edges643. In the case of hitting a flat facetMoreover, the specular point is used to launch new reflected and transmitted rays. The surface input impedance of the facet dipole antenna is treated as an infinite dielectric medium interface, at which the reflection and transmission coefficients are calculatedZ_A = 73 + j42. In the case of hitting an edge, new diffracted rays 5 &Omega;. These dipole radiators are generated in the sceneconnected via 50&Omega; transmission lines to a 50&Omega; source or load. HoweverTherefore, only those who reach there is always a nearby receiver in their line certain level of sight are ever taken into account. In other words, diffractions are treated locallyimpedance mismatch that violates the conjugate match condition for maximum power.

<table><tr><td> [[File:Dipole radiators.png|thumb|720px|EM.Cube]]Terrano's [[Propagation Module]] allows you to draw any type of surface or solid CAD objects under impenetrable 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 nonnative half-flat surfaces have to be discretized in the form of a collection of smaller flat facets. [[EM.Cube]] uses a triangular surface mesh generator to discretize the penetrable wave dipole transmitter and impenetrable [[Surface Objects|surface objects]] of your propagation scene. This mesh generator is very similar to the ones used in [[EMreceiver.Cube]]'s two other modules: MoM3D and Physical Optics (PO). </td></tr></table>

You can build On the other hand, we you specify a user-defined antenna pattern for the transmitter or receiver sets, you import a variety 3D radiation pattern file that contains all the values of surface E_&theta; and [[Solid Objects|solid objects]] using E_&phi; for all the combinations of (&theta;, &phi;) angles. Besides the three native dipole radiators, [[EM.Cube]]'s native &quot;Curve&quot; CAD objects like lines, polylines, circles, etc. You can use tools like Extrude, Loft, Stripalso provides 3D radiation pattern files for three X-Sweep, PipeY-Sweep, etcand Z-polarized half-wave resonant dipole antennas. to transform curves into surface or These pattern data were generated using a full-wave solver like [[Solid Objects|solid objectsEM.Libera]]'s wire MOM solver. '''However, keep in mind that all The names of the &quot;Curve&quot; CAD objects radiation pattern files are ignored by the SBR mesh generator and are therefore not sent to the simulation engine.''':

You can view and examine they are located in the discretized version of folder "\Documents\EMAG\Models" on your scene objects as they computer. Note that these are sent to the SBR full-wave simulation enginedata and do not involve any approximate assumptions. To view the mesh, click the '''Mesh''' [[File:mesh_tool.png]] button of the Simulate Toolbar or select '''Simulate &gt; Discretization &gt; Show Mesh''', or use these files as an alternative to the keyboard shortcut '''Ctrl+M'''. A triangular surface mesh of your physical structure appears in the project workspace. In this casenative dipole radiators, [[EM.Cube]] enters it mesh view mode. You can perform view operations like rotate view, pan, zoom, etc. But you cannot need to select objects, or move them or edit their properties. To get out of the Mesh View and return to [[EM.Cube]]'s Normal View, press the ''User Defined Antenna Pattern'Esc Key''' of radio button as the keyboard, or click the Mesh button of radiator type in the Simulate Toolbar once again, transmitter or go to the Simulate Menu and deselect the '''Discretization &gt;''' '''Show Mesh''' itemreceiver set property dialog.

You can adjust === A Note on the mesh resolution and increase the geometric fidelity Rotation 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. To adjust the mesh resolution, open the Mesh Settings Dialog by clicking the '''Mesh Settings''' [[File:mesh_settings.png]] button of the Simulate Toolbar or select '''Simulate &gt; Discretization &gt;''' '''Mesh Settings...'''. This dialog provides a single [[parameters]]: '''Edge Length'''., which has a default value of 100 project units. If you are already in the Mesh View Mode and open the Mesh Settings Dialog, you can see the effect of changing the edge length using the '''Apply''' button. Click OK to close the dialog.Antenna Radiation Patterns ===

Note that unlike [[EM.Cube]]Terrano's other computational modules Transmitter Set dialog and Receiver Set dialog both allow you to rotate an imported radiation pattern. In that express the default mesh density based on the wavelengthcase, you need to specify the resolution of '''Rotation''' angles in degrees about the SBR mesh generator X-, Y- and Z-axes. It is expressed important to note that these rotations are performed sequentially and in project length unitsthe following order: first a rotation about the X-axis, then a rotation about the Y-axis, and finally a rotation about the Z-axis. The default edge length value of 100 units might be too large for nonIn 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-flat objectsaxis transforms the XYZ LCS to a new primed X^&prime;Y^&prime;Z^&prime; LCS. You may have The second rotation is performed with respect to the new Y^&prime;-axis and transforms the X^&prime;Y^&prime;Z^&prime; LCS to use a lower value new double-primed X^{&prime;&prime;}Y^{&prime;&prime;}Z^{&prime;&prime;} LCS. The third rotation is finally performed with respect to capture the curvature of your curved structures adequatelynew Z^{&prime;&prime;}-axis. The figures below shows single and double rotations.

<table><tr><td> [[File:prop_manualPROP22B.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-29axis.]] </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>

In [[EM.Cube]], terrain objects To better understand why there are represented by and saved as special &quot;Tessellated&quot; objects with quadrilateral cells. This is true two separate sets of terrain objects points in the scene, note that you a point array (CAD object) is used to create yourself using [[EMa uniformly spaced base set.Cube]]'s Terrain Generator The array object always preserves its grid topology as well as all you move it around the terrain objects that you import from external files to your projectscene. The center of each cell represents However, the terrain elevation at that transmitters or receivers associated with this point. Tessellated objects array object are considered as discretized objects by [[EM.Cube]] elevated above the irregular terrain and they are not meshed one more time by the SBR mesh generatorno longer follow a strictly uniform grid. Each quadrilateral cell is divided into two triangular cells before being passed to If you move the SBR simulation engine. Therefore, when using [[EM.Cube]]'s Terrain Generator base set from its original position to create a new terrain objectlocation, you have to pay special attention to the resolution of base points' topology will stay intact, while the terrain object as it determines associated transmitters or receivers will be redistributed above 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 problembased on their new elevations.

You can use <table><tr><td> [[EMImage:PROP MAN8.Cube]]'s &quot;Polymesh&quot; tool to discretize solid png|thumb|left|640px|A transmitter (red) and a grid of receivers (yellow) adjusted above a plateau terrain surface CAD objects. You can manually control The underlying base point sets (blue and orange dots) associated with the mesh characteristics of polymesh objects including inserting new nodes adjusted transmitters and receivers on faces and edges or deleting existing nodes. In addition, [[EM.Cube]]'s Solid Generator and Surface Generator tools create ploymesh solids and surfaces, respectively. Like tessellated object, polymesh objects the terrain are also considered as discretized objects by [[EMvisible in the figure.Cube]] and they are not meshed again by the SBR mesh generator. </td></tr></table>

=== SBR Mesh Rules &amp; Considerations =Discretizing the Propagation Scene in EM.Terrano ==

In [[EM.Cube]]many practical scenarios, however, your buildings and all other CAD objects are initially created on may have curved surfaces, or the XY plane by defaultterrain may be irregular. In other words, the Z-coordinate EM.Terrano allows you to draw any type of the local coordinate system (LCS) of all blocks is set to zero until you change them. As long surface or solid geometric objects such as you use the global groundcylinders, cones, etc. under impenetrable and penetrable surface groups or penetrable volumes. EM.Terrano's mesh generator creates a triangular surface mesh of all is fine as your buildings are seated on the ground. When objects in your propagation scene has an irregular terrain, you want to place your which is called a facet mesh. Even the walls of cubic buildings on the terrain and not buried under it. Buildings in [[EM.Cube]] are not adjusted to the terrain elevation automaticallymeshed using triangular cells. You need to instruct [[This enables EM.Cube]] Terrano to do soproperly discretize composite buildings made of conjoined cubic objects.

To update the building positions and adjust their elevation to the underlying terrainUnlike [[EM.Cube]]'s other computational modules, right click on the '''Terrain''' item density or resolution of the Navigation Tree and select ''EM.Terrano'Adjust Scene Elevation''' from s surface mesh does not depend on the context menu. All the blocks operating frequency and is not expressed in terms of the scene are automatically elevated in the Z direction such that their bases sit on the terrainwavelength. In effectThe sole purpose of EM.Terrano's facet mesh is to discretize curved and irregular scatterers into flat facets and linear edges. Therefore, all geometrical fidelity is the blocks are translated along only criterion for the global Z axis by proper amounts such quality of a facet mesh. It is important to note that their local Z coordinate equals the Z-elevation discretizing smooth objects using a triangular surface mesh typically creates a large number of small edges among the underlying terrain objectfacets that are simply mesh artifacts and should not be considered as diffracting edges. This feature For example, each rectangular face of a cubic building is particularly useful if you change subdivided into four triangles along the location 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 terrain or import a new terrain after the blocks have been createdSBR solver to run accurate and computationally efficient simulations.

Note: You have to make sure that === Generating the resolution of your terrain, its fluctuation scale and building dimensions are all comparable. Otherwise, on a high-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.Facet Mesh ===

[[File:prop_adjust1_tnYou can view and examine the discretized version of your scene's objects as they are sent to the SBR simulation engine.png|400px]] [[File:prop_adjust2_tnYou 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.png|400px]]

Figure<table><tr><td> [[Image: A Scene with Buildings and Terrain Before and After Adjusting Elevationprop_manual-29.png|thumb|left|480px|EM.Terrano's mesh settings dialog.]] </td></tr></table>

In [[EMImage:Info_icon.Cubepng|30px]], 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 Click here to learn more about the new location. For example, you usually define a grid properties of receivers using a base set that is made up of a uniformly spaced array of points and spread them in your scene'''[[Glossary_of_EM. All of these receivers have the same height because their associated base points all have the same ZCube%27s_Simulation-coordinateRelated_Operations#Facet_Mesh | EM. 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, tooTerrano's Facet Mesh Generator]]'''.

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<table><tr><td> [[Image:UrbanCanyon2. png|thumb|left|640px|The Z-coordinate facet mesh of a transmitter or receiver is now the sum of buildings in the terrain elevation at the base point and the specified height. [[urban propagation scene generated by EM.CubeTerrano's Random City wizard with a cell edge length of 100m.]] gives you the option to adjust the transmitter and receiver sets to the terrain elevation</td></tr><tr><td> [[Image:UrbanCanyon3. This is done for individual transmitter sets and individual receiver sets. At the top png|thumb|left|640px|The facet mesh of the Transmitter Dialog there is a check box labeled &quot;'''Adjust Tx Sets to Terrain Elevation'''&quot;. Similarly, at buildings in the top of the Receiver Dialog there is a check box labeled &quot;'''Adjust Rx Sets to Terrain Elevation'''&quot;. These boxes are unchecked urban propagation scene generated by defaultEM. As a result, your transmitter sets or receiver sets coincide Terrano's Random City wizard 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 cell edge length of their associated base points by the amount of terrain elevation as can be seen in the figure below10m. ]] </td></tr></table>

To better understand why there are two separate sets of points == Running Ray Tracing Simulations in 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 elevationsEM.Terrano ==

[[File:prop_txrx1_tnEM.png|400px]] [[FileTerrano provides a number of different simulation or solver types:prop_txrx2_tn.png|400px]]

An SBR analysis * Set the units of your project and the frequency of operation. Note that the default project unit is '''millimeter'''. Wireless propagation problems usually require meter, mile or kilometer as the simplest project unit.* Create the blocks and draw the buildings at the desired locations.* Keep the default ray tracing simulation domain and involves accept the following steps: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.

# Set the unit of project scene and the frequency of operation. Note that [[You can access EM.Cube]]Terrano's default project unit is millimeter. When working with Simulation Run dialog by clicking the '''Run''' [[Propagation ModuleFile:run_icon.png]], pay attention to button of the project unit. Radio propagation problems usually require meter, mile '''Simulate Toolbar''' or kilometer as the project unitby selecting '''Simulate &rarr; Run.# Create the blocks and draw the buildings at the desired locations.# Keep the default ray domain and accept the default global ground .''' or change its material propertiesusing the keyboard shortcut {{key|Ctrl+R}}.# Define When you click the base sets (at least one for {{key|Run}} button, a new window opens up that reports the transmitter and one for different stages of the receiver).# Define the transmitter SBR simulation and receiver(s) using indicates the available base setsprogress of each stage.# Run After the SBR simulation engine.# Visualize the coverage map is successfully completed, a message pops up and plot other dataprompts the completion of the process.

You can access the <table><tr><td> [[Propagation Module]]Image:Terrano L1 Fig16.png|thumb|left|480px|EM.Terrano's simulation run dialog by clicking the '''Run''' [[File:run_icon.png]] button of the '''Simulate Toolbar''' or by selecting '''Simulate &gt; Run...''' or using the keyboard shortcut '''Ctrl+R'''. When you click the '''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.</td></tr></table>

<table><tr><td> [[FileImage:PROP12PROP MAN10.png|thumb|left|550px|EM.Terrano's output message window.]]</td></tr></table>

=== There are a number of SBR simulation settings that can be accessed and changed from the Ray Tracing Engine Settings Dialog. To open this dialog, click the button labeled {{key|Settings}} on the right side of the '''Select Simulation Parameters ===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.

There are EM.Terrano allows a finite number of SBR simulation settings ray bounces for each original ray emanating from a transmitter. This is very important in situations that can be accessed may involve resonance effects where rays get trapped among multiple surfaces and changed from the SBR Settings Dialogmay bounce back and forth indefinitely. To open this dialog, click This is set using the button box labeled &quot;'''SettingsMax No. Ray Bounces''' on &quot;, which has a default value of 10. Note that the right side maximum number of ray bounces directly affects the '''Select Engine''' dropdown list in computation time as well as the Run Dialog. [[EMsize of output simulation data files.Cube]]'s SBR simulation engine allows you to separate This can become critical for indoor propagation scenes, where most of the physical effects that are calculated during rays undergo a ray tracing processlarge number of reflections. You can selectively enable or disable Two other parameters control the diffraction computations: '''Ray Reflection''', '''Ray TransmissionMax Wedge Angle''' in degrees and '''Ray DiffractionMin Edge Length'''in project units. By 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, all three effects are checked and included in value of the computationsmaximum wedge angle is 170&deg;. Separating these effects sometimes help you better analyze your propagation scene and understand The minimum edge length is size of the impact common edge between two conjoined facets that is considered as a mesh artifact and not a real diffracting edge. The default value of various blocks in the sceneminimum edge length is one project units.

<table><tr><td> [[Image:PROP MAN11.png|thumb|left|720px|EM.Cube]] requires 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 certain group of surfaces and may bounce back and forth indefinitely. This is set using the box labeled &quot;Terrano'''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 s SBR simulation data filesengine settings dialog. This can become critical for indoor propagation scenes, where most of the rays undergo a large number of reflections. ]] </td></tr></table>

As rays travel in the scene and bounce from surfaces, they lose their power , and their amplitudes gradually diminish. From a practical point of view, only rays that have power levels above the receiver sensitivity threshold can be effectively received. Therefore, all the rays whose power levels fall below a specified power threshold are discarded. The '''Ray Power Threshold''' is specified in dBm and has a default value of -100dBm150dBm. 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.

You can also set the '''Ray Angular Resolution''' of the transmitter rays in degrees. By default, every transmitter emanates equi-angular ray tubes at a resolution of 1 degree. Lower angular resolutions larger than 1° speed up the SBR simulation significantly, but they may compromise the accuracy. Higher angular resolutions less than 1° increase the accuracy of the simulating results, but they also increase the computation time. The SBR Engine Settings dialog also displays the '''Recommended Ray Angular Resolution''' in degrees in a grayed-out box. This number is calculated based on the overall extents of your computational domain as well as the SBR mesh resolution. To see this value, you have to generate the SBR mesh first. Keeping the angular resolution of your project above this threshold value makes sure that the small mesh facets at very large distances from the source would not miss any impinging ray tubes during the simulation.

[[File:PROP13EM.Terrano gives a few more options for the ray tracing solution of your propagation problem. For instance, it allows you to exclude the 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.png]]

Figure 1: [[Propagation Module]]At the end of a ray tracing simulation, the electric field of each individual ray is computed and reported. By default, the actual received ray fields are reported, which are independent of the radiation pattern of the receive antennas. EM.Terrano provides a check box labeled "Normalize ray's SBR Engine Settings dialogE-field based on receiver pattern", which is unchecked by default.If this box is checked, the field of each ray is normalized so as to reflect that effect of the receiver antenna's radiation pattern. The received power of each ray is calculated from the following equation:

<math> P_{ray} === The Coverage Map ===\frac{ | \mathbf{E_{norm}} |^2 }{2\eta_0} \frac{\lambda_0^2}{4\pi} </math>

If It can be seen that if the associated radiator set ray's E-field is isotropicnot normalized, so the computed ray power will be the transmitter set. By default, an isotropic transmitter has vertical polarization. You can use the '''Polarization''' radio button correspond to select one of the two options: '''Vertical''' 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 that of a short dipole radiator, you can set a value for the dipole current in Amperespolarization matched isotropic receiver. The radiation resistance of a short dipole of length ''dl'' is given by:

:<math> R_r = 80\pi^2 \left( \frac{dl}{\lambda_0} \right)^2 </math><!--[[File:eqngr6.png]]-->== Polarimetric Channel Analysis ===

In a 3D SBR simulation, a transmitter shoots a large number of rays in all directions. The radiated 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 a short dipole carrying a current I₀ 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 given used to compute the total received power by:each individual receiver.

:From a theoretical point of 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 assume ideal isotropic radiators at these points and compute the polarimetric transfer function matrix of the propagation channel. This matrix relates the received electric field at each receiver location to the transmitted electric field at each transmitter location. In general, the 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 '''E<mathsub> P_{rad} = \frac{1}{2} R_r |I_0|^2 = 40\pi^2 |I_0|^2 \left( \frac{dl}{\lambda_0} \right)^2 &theta;</mathsub>''' and '''E<!--[[File:shortdipole.png]]--sub>&phi;</sub>''' field components associated with each ray at the receiver location to its '''E_&theta;''' and '''E_&phi;''' field components at the transmitter location. Each ray has a delay and &theta; and &phi; angles of departure at the transmitter location and &theta; and &phi; angles of departure at the receiver location.

For isotropic and user defined radiators you can set the '''Input Power''To perform a polarimatric channel characterization of your propagation scene, open EM.Terrano' s Run Simulation dialog and select '''PhaseChannel Analyzer''' of a transmitter set in Watts and degrees, respectively. This can be accessed from the drop-down list labeled '''Transmitter ChainSelect Simulation or Solver Type''' dialog, which will be described in detail in . At the next section. The radiation pattern end of the associated radiator set simulation, a large ray database is normalized and used in conjunction generated with the input power value to create a weighted distribution of transmitted raystwo data files called "sbr_channel_matrix. In certain cases like hybrid simulations, you may want to use the actual values of the far field to define the transmitter power rather than a normalized radiation patternDAT" and "sbr_ray_path. Note that the pattern (DAT".RAD) The former file contains the value of total radiated power in its header. In this casedelay, check the box labeled '''&quot;Calculate Power From Radiation Pattern&quot;'''. This is calculated directly from the complex &theta; and &phi; components angles 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 arrival and limit the '''Angular Extents''' of rays to a certain solid angle around the transmitter. This is especially useful departure and computationally efficient when the transmitter is on one side complex-valued elements of the scene, and channel matrix for all the scatterers and receivers are on the other side. In this case, there is no need to generate individual rays in all directions. To limit the angular extents of rays, define the Start that leave each transmitter and End values for both Theta (&theta;) and Phi (&phi;) anglesarrive at each receiver. The value of latter file contains the angular resolution geometric aspects of the rays can be changed from the Run Dialog each ray such as will be discussed laterhit point coordinates.

In a regular SBR simulation, you have a transmitter and one or more arrays of receivers in your scene. At the end of the simulation, you can visualize the coverage map of the transmitter over the receiver sets. A coverage map shows the total '''Received Power''' by each of the receivers and is visualized as a color-coded intensity plot. You can visualize the coverage maps of individual receiver sets. At the end of a SBR simulation, each Received Power Coverage Map is listed under the receiver set's name in the Navigation Tree. To display a coverage map, simply click on its entry in the Navigation Tree. === The coverage map plot appears in the Main Window overlaid on the scene. A legend box on the right shows the color scale and units (dB). The 3-D coverage maps are displayed as horizontal confetti above the receivers. If the receivers are packed close to each other, you will see a continuous confetti map. If the receivers are far apart, you will see individual colored squares. You can also visualize coverage maps as colored 3"Near Real-D cubes. This may be useful when you set up your receivers in a vertical arrangement or the scene has a highly uneven terrain. To change the type of coverage map visualization, open the receiver set's property dialog and select the desired option for '''Coverage Map: Confetti''' or '''Cube''' in the '''&quot;Visualization Options&quot;''' section of the dialog.Time" Polarimatrix Solver ===

[[File:prop_run11_tnAfter EM.png|400px]] [[File:prop_run12_tnTerrano'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 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 '''Polarimatrix Solver''', which is the third option of the drop-down list labeled '''Select Simulation or Solver Type''' in EM.Terrano's Run Simulation dialog. The results of the Polarimatrix and 3D SBR solvers must be identical from a theoretical point of view. However, there might be small discrepancies between the two solutions due to roundoff errors.png|400px]]

Figure: Received power coverage map: (Left) confetti style, Using 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 (Right) cube stylereceivers.Certain simulation modes of EM.Terrano are intended for the Polarimatrix solver only as will be described in the next section.

You can change the settings of the coverage map by right clicking on its entry in the Navigation Tree and selecting '''Properties...''' or by double-clicking on the legend box. {{Note| In order to use the Output Plot Settings dialogPolarimatrix solver, you can choose from one must first generate a ray database of three Color Map options: '''Default''', '''Rainbow''' and '''Grayscale'''your propagation scene using EM. The visualization plot uses default values for the color scale. In the section titled &quot;Limits&quot;, you can choose the radio button labeled Terrano'''User Defined'''. Then, you have to enter new values for the '''Lower''' and '''Upper''' Limits of the plot. You can also show or hide the Legend Box or change its '''Background''' and '''Foreground''' colors by clicking the buttons provided for this purposes Channel Analyzer.}}

[[File:prop_run4=== EM.png]]Terrano's Simulation Modes ===

{| class="wikitable"|-! scope="col"| Simulation Mode! scope= The Ray Data "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;" | [[Parametric_Modeling_%26_Simulation_Modes_in_EM.Cube#Running_Frequency_Sweep_Simulations_in_EM.Cube | Frequency Sweep]]| style="width:180px;" | 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.Cube | 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|}

At the end of a SBR simulation, Click on 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 above 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'''learn more about each simulation mode.

[[File:prop_run5_tnYou set the simulation mode in EM.Terrano's simulation run dialog using the drop-down list labeled '''Simulation Mode'''. A single-frequency analysis is a single-run simulation. 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.png|800px]]

Visualization of received rays at {{Note| EM.Terrano's frequency sweep simulations are very fast because the location geometrical optics (ray tracing) part of the selected receiversimulation is frequency-independent.}}

* Delay is When your propagation scene contains two or more transmitters, whether they all belong to the total time delay that a ray experiences travelling from same transmitter set with the same radiation pattern or to different transmitter sets, EM.Terrano assumes all to the 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 after all . In a transmitter sweep, on the reflectionsother hand, transmissions and diffractions and is expressed in nanosecondsEM.* Ray Field is the received electric field Terrano assumes only one transmitter broadcasting at the receiver location due to a specific ray and is given in dBV/mtime.* Ray Power is The result of the sweep simulation is a number of received power at the receiver due coverage maps, each corresponding to a specific ray and is given transmitter in dBm.* Angles of Arrival are the &theta; and &phi; angles of the incoming ray at the local spherical coordinate system of the receiverscene.

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{{Note| EM. 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 Terrano'''ID''' and highlighting its row in s transmitter sweep works only with the table. In that case, the selected rays is highlighted in the Project Workspace Polarimatrix Solver and all requires an existing ray database previously generated using the other rays become thin (faded)Channel Analyzer.}}

[[File:prop_run6_tnYou 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|800px]]

Figure: Analyzing a selected ray from {{Note| EM.Terrano's rotational sweep works only with the Polarimatrix Solver and requires an existing ray data dialogdatabase previously generated using the Channel Analyzer.}}

=== Plotting Other Simulation Results Mobile Sweep ===

Besides visualizing the coverage map and received rays In a mobile sweep, each transmitter is paired with a receiver according to their indices in the [[EMtheir parent sets.Cube|EM.CUBE]]'s [[Propagation Module]]At each simulation run, you can also plot the '''Path Loss''' of all the receivers belonging only one (Tx, Rx) pair is considered to a receiver set as well as be active in the '''Power Delay Profile''' of individual receiversscene. To plot these dataAs a result, go the '''Observables''' section generated coverage map takes a different meaning implying the sequential movement of the Navigation Tree transmitter and right click on the '''Receivers''' itemreceiver pair along their corresponding paths. From the context menuIn other words, select '''Plot Path Loss''' or '''Plot Power Delay Profile''', respectively. The path loss data between the active transmitter set of point transmitters and all the receivers belonging to a receiver set are plotted on a Cartesian graph. The horizontal axis of this graph represents point receivers indeed represent the index locations of the a single transmitter and a single receiverat different instants of time. Power Delay Profile It is a bar chart obvious that plots the power total number of individual rays received by the currently selected receiver versus their time delay. If there is a line transmitters and total number of sight (LOS) between a transmitter and receiver, the LOS ray will have the smallest delay and therefore will appear first receivers in the bar chartscene must be equal. Sometimes you may have several rays arriving at a receiver at the same timeOtherwise, iEM.e. all with the same delay, but with different power level. These Terrano will appear as stacked bars in the chartprompt an error message.

You can also plot the path loss and power delay profile graphs and many others from [[EM.Cube|EM.CUBE]]provides a 's data manager. You can open data manager by clicking the ''Mobile Path Wizard'Data Manager''' [[File:data_manager_icon.png]] button that facilitates the creation of the '''Compute Toolbar''' a transmitter set or by selecting '''Compute [[File:larrow_tna receiver set along a specified path.png]] Data Manager''' from the menu bar This path can be an existing nodal curve (polyline or by right clicking on the '''Data Manager''' item of the Navigation Tree and selecting Open Data Manager... from the contextual menu NURBS curve) or by using the keyboard shortcut '''Ctrl+D'''an existing line objects. In the Data manager Dialog, you will see You can also import a list of all the sptial Cartesian data files available for plotting. These include file containing the theta and phi angles of arrival and departure coordinates of the selected receiverbase location points. You can select any data file by clicking and highlighting its '''ID''' in the table and then clicking the '''Plot''' buttonFor more information, refer to [[Glossary_of_EM.Cube%27s_Wizards#Mobile_Path_Wizard | Mobile Path Wizard]].

At the end of an SBR simulation, the results are written into === Investigating Propagation Effects Selectively One at a main output data file with the reserved name of SBR_Results.RTOUT. This file has the following format:Time ===

Number <table><tr><td> [[Image:UrbanCanyon15.png|thumb|left|480px|The plot settings dialog of Raysthe 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>

<table><tr><td> [[Image:UrbanCanyon14.png|thumb|left|640px|EM.Terrano's simulation run dialog showing the check boxes for controlling various propagation effects.]] </td></tr></table> <table><tr><td> [[Image:UrbanCanyon11.png|thumb|left|640px|The received power coverage map of the random city scene with direct LOS rays only.]] </td></tr><tr><td> [[Image:UrbanCanyon12.png|thumb|left|640px|The received power coverage map of the random city scene with reflected rays only.]] </td></tr><tr><td> [[Image:UrbanCanyon13.png|thumb|left|640px|The received power coverage map of the random city scene with diffracted rays only.]] </td></tr></table> == Working with EM.Terrano's Simulation Data == === The Ray Tracing Solvers' Output Simulation Data === 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 a ray tracing simulation, all the polarimetric rays emanating from the transmitter(s) or other sources that are received by the individual receivers are computed, collected, sorted and saved into ASCII data files. From the ray data, the total electric field at the location of receivers as well as the total received power are computed. The 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. If you specify the 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. === Visualizing Field & Received Power Coverage Maps === In wireless propagation modeling for communication system applications, the received power at the receiver location is more important than the field distributions. In order to compute the received power, you need three pieces of information: * '''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. In a simple link scenario, the received power P_r in dBm is found from the following equation: <math> P_r [dBm] = P_t [dBm] + G_{TC} + G_{TA} - PL + G_{RA} + G_{RC} </math> 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 NumberData''', 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 Field 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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