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

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

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

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

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

Every wireless communication system involves a transmitter that transmits some sort of signal (voice, video, data, etc[[Image:Info_icon.), a receiver that receives and detects the transmitted signal, and a channel in which the signal is transmitted into the air and travels from the location of the transmitter png|30px]] Click here to learn more about the location '''[[Basic Principles 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 anglesSBR Ray Tracing | Basic SBR Theory]]'''.

The different rays arriving at a receiver location create constructive and destructive interference patterns. This is known as the multipath effect. This together with the shadowing effects caused by building obstructions lead to channel fading. In many wireless applications, the total received power by the receiver is all that matters. In some others, the angle of arrival of the rays as well as their polarization are of immense interest. A fully polarimetric, coherent ray tracer like <table><tr><td> [[EMImage:Manhattan1.png|thumb|left|420px|A large urban propagation scene featuring lower Manhattan.Cube]]'s Shooting-and-Bouncing-Rays (SBR) solver lets you compute and resolve all the rays received by a receiver including their power levels, time delays and angles of arrival.</td></tr></table>

=== Line-of-Sight vsEM. Multipath Terrano as the Propagation Channel Module of EM.Cube ===

In a free-space line-EM.Terrano is the ray tracing '''Propagation Module''' of-sight (LOS) communication system'''[[EM.Cube]]''', the signal propagates directly from the transmitter to the receiver without encountering any obstacles (scatterers)a comprehensive, integrated, modular electromagnetic modeling environment. Free-space line-EM.Terrano shares the visual interface, 3D parametric CAD modeler, data visualization tools, and many more utilities and features collectively known as [[Building_Geometrical_Constructions_in_CubeCAD | CubeCAD]] with all of-sight channels are ideal scenarios that can typically be used to model aerial or space communication system applications[[EM.Cube]]'s other computational modules.

Click here With the seamless integration of EM.Terrano with [[EM.Cube]]'s other modules, you can now model complex antenna systems in [[EM.Tempo]], [[EM.Libera]], [[EM.Picasso]] or [[EM.Illumina]], and generate antenna radiation patterns that can be used to learn more about model directional transmitters and receivers at the theory two ends of your propagation channel. Conversely, you can analyze a propagation scene in EM.Terrano, collect all the rays received at a certain receiver location and import them as coherent plane wave sources to [[EM.Tempo]], [[EM.Libera]], [[EM.Picasso]] or [[Free-Space Propagation ChannelEM.Illumina]].

[[Image:multi1_tnInfo_icon.png|thumb|400px|A multipath propagation scene showing all the rays arriving at a particular receiver.30px]]In ground-based systems, the presence of the ground as a very large reflecting surface affects the signal propagation Click here to a large extentlearn more about '''[[Getting_Started_with_EM. Along the path from a transmitter to a receiver, the signal may also encounter many obstacles and scatterers such as buildings, vegetation, etcCube | EM. In an urban canyon environment with many buildings of different heights and other scatterers, a line of sight between the transmitter and receiver can hardly be established. In such cases, the propagating signals bounce back and forth among the building surfaces. It is these reflected or diffracted signals that are often received and detected by the receiver. Such environments are referred to as “multipath”. The group of rays arriving at a specific receiver location experience different attenuations and different time delays. This gives rise to constructive and destructive interference patterns that cause fast fading. As a receiver moves locally, the receiver power level fluctuates sizably due to these fading effectsCube Modeling Environment]]'''.

The use === Advantages & Limitations of statistical 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 sizes. In such cases, one needs to perform a physics-based, site-specific analysis of the propagation environment to accurately identify and establish all the possible signal paths from the transmitter to the receiver. This involves an electromagnetic analysis of the scene with all of its geometrical and physical detailsEM. Terrano's SBR Solver ===

Link budget analysis for a multipath channel is a challenging task due to the large size of the computational domains involvedEM. Typical propagation scenes usually involve length scales Terrano's SBR simulation engine utilizes an intelligent ray tracing algorithm that is based on the order concept of thousands of wavelengthsk-dimensional trees. To calculate the path loss between the transmitter and receiver, one must solve Maxwell's equations A k-d tree is a space-partitioning data structure for organizing points in an extremely large a k-dimensional space. Fullk-wave numerical techniques like the Finite Difference Time Domain (FDTD) method, which require a fine discretization of the computational domain, d trees are therefore impractical particularly useful for solving large-scale propagation problems. The practical solution is to use asymptotic techniques searches that involve multidimensional search keys such as SBR, which utilize analytical techniques over range searches and nearest neighbor searches. In a typical large distances rather than radio propagation scene, there might be a brute force discretization large number of rays emanating from the transmitter that may never hit any obstacles. For example, upward-looking rays in an urban propagation scene quickly exit the entire computational domain. Such asymptotic techniquesRays that hit obstacles on their path, of courseon the other hand, have to compromise modeling accuracy for practical computation feasibilitygenerate new reflected and transmitted rays. The k-d tree algorithm traces all these rays systematically in a very fast and efficient manner. Another major advantage of k-d trees is the fast processing of multi-transmitters scenes.

=== The It is very important to keep in mind that SBR Method ===is an asymptotic electromagnetic analysis technique that is based on Geometrical Optics (GO) and the 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-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]]'s [[Propagation Module]] provides an asymptotic ray tracing simulation engine that is based on a technique known as Shooting-and-Bouncing-Rays (SBR). In this technique, propagating spherical waves are modeled as ray tubes or beams that emanate from a source, travel in space, bounce from obstacles and are png|thumb|left|500px|A multipath urban propagation scene showing all the rays collected by the a receiver. As rays propagate away from their source (transmitter), they begin to spread (or diverge) over distance. In other words, the cross section or footprint of a ray tube expands as a function of the distance from the source. [[EM.Cube]] uses an accurate equi-angular ray generation scheme to that produces almost identical ray tubes in all directions to satisfy energy and power conservation requirements.</td></tr></table>

When == EM.Terrano Features at a ray hits an obstructing surface, one or more of the following phenomena may happen:Glance ==

[[EM.Cube]] discretizes all the objects of the scene into flat triangular facets. Obviously, rectangular <ul> <li> Buildings/blocks with arbitrary geometries and cubic objects preserve their geometric shapes through this discretization. Objects material properties</li> <li> Buildings/blocks with curved impenetrable surfaces such as cylinders, cones or spherespenetrable 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, are approximated by &quot;polymesh&quot; representations. The geometric fidelity 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 the resulting mesh depends on the specified mesh edge length. When a ray hits a triangular facetdigital elevation map (DEM) terrain models</li> <li> Python-based random city wizard with randomized building locations, the propagating spherical wave is approximated as a plane wave at the specular point. The reflection extents and transmission coefficients orientations</li> <li> Python-based wizards for generation of the surface are calculated at the operational frequency parameterized multi-story office buildings and at several terrain scene types</li> <li> Standard half-wave dipole transmitters and receivers oriented along the particular ray incident angle. 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 transceivers)</li></ul>

A receiver may receive a large number of rays: direct line<ul> <li> Fully 3D polarimetric and coherent Shoot-ofand-sight rays Bounce-Rays (SBR) simulation engine</li> <li> GTD/UTD diffraction models for diffraction from the transmitter, rays reflected or diffracted off the ground or building edges and terrain, rays reflected or diffracted from buildings or rays transmitted through buildings. Each received </li> <li> Triangular surface mesh generator for discretization of arbitrary block geometries</li> <li> Super-fast geometrical/optical ray tracing using advanced k-d tree algorithms</li> <li> Intelligent ray is characterized by its power, delay tracing with user defined angular extents and angles of arrivalresolution</li> <li> Ray reflection, which are the spherical coordinate angles &theta; edge diffraction and &phi; of the incoming ray. The actual signal received transmission through multilayer walls and detected by material volumes</li> <li> Communication link analysis for superheterodyne transmitters and receivers</li> <li> 17 digital modulation waveforms for the receiver is the superposition calculation of all these rays with different power levels E_b/N₀ and different time delays. Most Bit error rate (BER)</li> <li> Incredibly fast frequency sweeps of the time, you will be interested entire propagation scene in the coverage map a single SBR simulation run</li> <li> Parametric sweeps of an areascene elements like building properties, which shows how much power is received by a grid or radiator heights and rotation angles</li> <li> Statistical analysis of receivers spread over the area from propagation scene</li> <li> Polarimetric channel characterization for MIMO analysis</li> <li> "Almost real-time" Polarimatrix solver using an existing ray database</li> <li> "Almost real-time" transmitter sweep using the Polarimatrix solver</li> <li> "Almost real-time" rotational sweep for modeling beam steering using the Polarimatrix solver</li> <li> "Almost real-time" mobile sweep for modeling mobile communications between Tx-Rx pairs along a given fixed transmitter.mobile path using the Polarimatrix solver</li></ul>

[[EM.Cube]]'s SBR simulation engine can be used as == Building a versatile and powerful asymptotic electromagnetic (EM) solver. If you compare [[EM.Cube]]'s [[Propagation Module]] with its other computational modules, you will notice a lot of similarities. While other modules group objects primarily by their material properties, [[Propagation Module]] categorizes the types of obstructing surfaces. Besides sharing the same ray-surface interaction mechanisms, all the objects belonging to a surface group also share the same material properties. [[Propagation Module]] offers similar source types and similar observable types as the other computational modules. For instance, the Hertzian dipole sources used Scene in a SBR simulation are identical to those offered in PO, MoM3D and Planar modules. The plane wave sources are identical across all computational modules. [[Propagation Module]]'s sensor field planes, far field observables (either radiation patterns or RCS) and Huygens surfaces are all fully compatible with [[EM.Cube]]'s other computational modules.Terrano ==

As an asymptotic EM solver, the SBR engine can be used to model large-scale electromagnetic radiation and scattering problems. An example of this kind is radiation of simple or complex antennas in the presence of large scattering platforms. You have to keep in mind that by using an asymptotic technique in place === The Various Elements of a full-wave method, you trade computational speed and lower memory requirements for modeling accuracy. In particular, the [[SBR Method|SBR method]] cannot take into account the electromagnetic coupling effects among nearby radiators or scatterers. However, when your scene spans thousands of wavelengths, an SBR simulation might often prove to be your sole practical solution. Propagation Scene ===

=== Pros A 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 Cons 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's SBR Solver ===, a transmitter represents a point source, while a receiver represents a point observable. Both a transmitter and a receiver are associated with point objects, which are one of the many types of geometric objects you can draw in the project workspace. Your scene might involve more than one transmitter and possibly a large grid of receivers.

[[EM.Terrano]]'s SBR simulation engine utilizes an intelligent ray tracing algorithm that is based on the concept of k-dimensional trees. A k-d tree is a space-partitioning data structure for organizing points in a k-dimensional space. k-d trees are particularly useful for searches that involve multidimensional search keys such as range searches and nearest neighbor searches. In a typical large radio more complicated propagation sceneusually contains several buildings, there might be a large number of rays emanating from the transmitter that may never hit any obstacles. For examplewalls, upward-looking rays in an urban propagation scene quickly exit the computational domain. Rays that hit obstacles on their path, on the or other hand, generate new reflected kinds of scatterers and transmitted rayswave obstructing objects. The k-d tree algorithm traces You model all of these rays systematically elements by drawing geometric objects in a very fast and efficient mannerthe project workspace or by importing external CAD models. Another major advantage of k-d trees is EM.Terrano does not organize the fast processing geometric objects of multi-transmitters scenesyour project workspace by their material composition. Unlike Rather, it groups the previous versions geometric objects into blocks based on a common type of the SBR solver which could handle one transmitter at a time and would superpose all the resulting interaction with incident rays at . EM.Terrano offer the end following types of the simulation, the new SBR shoots rays from all the transmitters at the same time. object blocks:

{| 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.TerranoCube's Materials, Sources, Devices & Other Physical Object Types#Impenetrable Surface | Impenetrable Surface]]| style="width:200px;" | Ray reflection, ray diffraction| style="width:250px;" | All solid & surface geometric objects, no curve objects| style="width:300px;" | Basic building group for outdoor scenes|-| style="width:30px;" | [[File:penet_surf_group_icon.png]]| style="width:150px;" | [[Glossary of EM.Cube's SBR solver performs fully polarimetric Materials, Sources, Devices & Other Physical Object Types#Penetrable Surface | Penetrable Surface]]| style="width:200px;" | Ray reflection, ray diffraction, ray transmission in free space| style="width:250px;" | All solid & surface geometric objects, no curve objects| style="width:300px;" | Behaves similar to impenetrable surface and coherent SBR simulations uses thin wall approximation for generating transmitted rays, used to model hollow buildings with arbitrary transmitter antenna patternsray penetration, entry and exit |-| style="width:30px;" | [[File:terrain_group_icon. The new engine solves directly for the vectorial field components at the receiver locations or field observation pointspng]]| style="width:150px;" | [[Glossary of EM. This is far more rigorous than 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 curve objects | style="width:300px;" | Behaves exactly like impenetrable surface but can change the previous versions elevation of all the SBR solver which primarily utilized ray power calculations based on the two vertical buildings and horizontal polarizationstransmitters and receivers located above it|-| style="width:30px;" | [[File:penet_vol_group_icon. In other words, png]]| style="width:150px;" | [[Glossary of EM.Cube]]'s new SBR engine is a truly asymptotic Materials, Sources, Devices &quotOther Physical Object Types#Penetrable Volume | Penetrable Volume]]| style="width:200px;field&quot" | Ray reflection, ray diffraction, ray transmission and ray attenuation inside homogeneous material media| style="width:250px; solver. As " | All solid geometric objects, no surface or curve objects| style="width:300px;" | Used to model wave propagation inside a resultvolumetric material block, you can visualize also used for creating individual solid walls and interior building partitions and panels in indoor scenes|-| style="width:30px;" | [[File:base_group_icon.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 magnitude definition of transmitters and phase receivers|-| style="width:30px;" | [[File:scatterer_group_icon.png]]| style="width:150px;" | [[Glossary of all six electric EM.Cube's Materials, Sources, Devices & Other Physical Object Types#Point Scatterer Set | Point Scatterer Set]]| style="width:200px;" | Ray reception and magnetic field components at any ray scattering| style="width:250px;" | Only point in , box and sphere objects| style="width:300px;" | Required for the computational domaindefinition of point scatterers as targets in a radar simulation |-| style="width:30px;" | [[File:Virt_group_icon. For power calculations at the receiver locationpng]]| style="width:150px;" | [[Glossary of EM.Cube's Materials, an isotropicSources, polarizationDevices & 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-matched, receiving antenna is assumed. physical items |}

In most scenes, the buildings and the ground or terrain can be assumed Click on each type to be made of homogeneous materials. These are represented by their electrical properties such as permittivity e and electric conductivity s. More complex scenes may involve a multilayer ground or multilayer building walls. In such cases, one can no longer use learn more about it in the simple reflection or transmission coefficient formulas for homogeneous medium interfaces. [[Glossary of EM.Cube's Materials, Sources, Devices & Other Physical Object Types]] calculates the reflection and transmission coefficients of multilayer structures as functions of incident angle, frequency and polarization and uses them at the respective specular points.

It is very important to keep in mind that SBR is an asymptotic electromagnetic analysis technique that is based on Geometrical Optics (GO) Impenetrable surfaces, penetrable surfaces, terrain surfaces and penetrable volumes represent all the Uniform Theory objects that obstruct the propagation of Diffraction electromagnetic waves (UTDrays)in the free space. It What differentiates them is not a &quot;full-wave&quot; technique, and it does not solve Maxwell's equations directly or numericallythe types of physical phenomena that are used to model their interaction with the impinging rays. EM. SBR makes Terrano discretizes geometric objects into a number of assumptionsflat facets. The field intensity, chief among them, a very high operational frequency such that phase and power of the length scales involved are much larger than reflected and transmitted rays depend on the operating wavelengthmaterial properties of the obstructing facet. Under this assumed regime, electromagnetic waves start to behave like optical raysThe specular surface of a facet can be modeled locally as a simple homogeneous dielectric half-space or as a multilayer medium. Virtually In that respect, all the calculations in SBR are based on far field approximationsobstructing objects such as buildings, walls, terrain, etc. behave in a similar way:

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 * They terminate an impinging ray and replace it with one or more new secondary rays. The power * They represent a specular interface between two media of diffracted rays drops much faster than reflected rays. [[EM.Cube]] ignores diffracted rays that are not detected by any receiver. In other wordsdifferent material compositions for calculating the reflection, 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 dotransmission or diffraction coefficients.

An [[EM.Cube]] propagation scene typically consists of several elements. At a minimum, you need a transmitter (Tx) at some location Sometimes it is helpful to launch rays into draw graphical objects as visual clues in the scene and a receiver (Rx) at another location project workspace. These non-physical objects must belong 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) channelvirtual object group. A transmitter is one of [[Virtual objects are not discretized by EM.Cube]]Terrano's several source typesmesh generator, while a receiver is one and they are not passed onto the input data files 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 planeSBR simulation engine.

<table><tr><td> [[Image:PROP MAN2.png|thumb|left|720px|An outdoor urban propagation scene may involve several buildings (modeled as impenetrable surfaces) generated by EM.Terrano's "Random City" and an underlying flat ground or irregular terrain surface"Basic Link" wizards. An indoor propagation scene may involve several walls (modeled as thin penetrable surfaces)It consists of 25 cubic brick buildings, a ceiling one transmitter and a floor arranged according to a certain floor plan. You can also build mixed scenes involving both impenetrable and penetrable blocks, possibly along with irregular terrain surfaces. Your sources and observables can be placed anywhere in the scene. Your transmitters and large two-dimensional array of receivers can be placed outdoors or indoors. A complete list of the various elements of a propagation scene is given in the '''Physical Structure''' section of [[Propagation Module]]'s Navigation Tree as follows:</td></tr></table>

ImpenetrableIn EM.Terrano, all the geometric objects associated with the various scene elements like buildings, penetrable and terrain surfaces all obstruct and base location points are grouped together as blocks based on their common type. All the propagation of electromagnetic waves (rays) objects listed under a particular group in the free spacenavigation tree share the same color, texture and material properties. What differentiates them is Once a new block group has been created in the types navigation tree, it becomes the "Active" group of physical phenomena that are used to model their interaction with the impinging rays. Base points are simply used to define transmitter and receiver locations project workspace, which is always displayed in bold letters. You can draw new objects under the sceneactive node. The following sections of this manual will describe each of these elements Any block group can be made active by right-clicking on its name in detailthe navigation tree and selecting the '''Activate''' item of the contextual menu.

<table><tr><td> [[FileImage:PROP14(1)PROP MAN1.png|thumb|left|480px|EM.Terrano's navigation tree.]]</td></tr></table>

Figure 1: The Navigation Tree of [[It is recommended that you first create block groups, and then draw new objects under the active block group. However, if you start a new EM.Cube]]'s [[Propagation Module]]Terrano project from scratch, and start drawing a new object without having previously defined any block groups, a new default impenetrable surface group is created and added to the navigation tree to hold your new CAD 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.

* They terminate an impinging ray and replace it with one You can move any geometric object or more new rays.* They represent a specular interface between two media selection of objects from one block group to another. You can also transfer objects among [[EM.Cube]]'s different material compositions for calculating the reflectionmodules. For example, transmission you often need to move imported CAD models of terrain or buildings from CubeCAD to EM.Terrano. To transfer objects, first select them in the project workspace or select their names in the navigation tree. Then right-click on them and possibly diffraction coefficientsselect <b>Move To &rarr; Module Name &rarr; Object Group</b> from the contextual menu. For example, if you want to move a selected object to a block group called "Terrain_1" in EM.Terrano, then you have to select the menu item '''Move To &rarr; EM.Terrano &rarr; Terrain_1''' as shown in the figure below. Note that you can transfer several objects altogether using the keyboards's {{key|Ctrl}} or {{key|Shift}} keys to make multiple selections.

<table><tr><td> [[EMImage:PROP MAN3.Cube]] has generalized png|thumb|left|720px|Moving the concept terrain model of '''Block''' as any object that obstructs and affects radio wave propagationMount Whitney originally imported from an external digital elevation map (DEM) file to EM. Rays hit the facets of a block and bounce off the surface of those facets or penetrate them and continue their propagationTerrano. Rays also get diffracted off the edges of these blocks. In ]]</td></tr><tr><td>[[Image:PROP MAN4.png|thumb|left|720px|The imported terrain model of Mount Whitney shown in EM.Cube]]Terrano's [[Propagation Module]], blocks are grouped together by the type of their interaction with raysproject workspace under a terrain group called "Terrain_1". [[EM.Cube]] currently offers three types of blocks for use in a propagation scene:</td></tr></table>

# '''Impenetrable Surfaces:''' Rays hit the facets === Adjustment of this type of blocks and bounce back, but they do not penetrate the object. It is assumed that the interior of such blocks or buildings are highly absorptive.# '''Penetrable Surfaces:''' These blocks represent thin surfaces that are used to model the exterior and interior walls of buildings based Block Elevation on the &quot;Thin Wall Approximation&quot;. Rays reflect off the surface of penetrable surfaces and diffract off their edges. They also penetrate such thin surfaces and continue their paths on the other side of the wall.# '''Underlying Terrain Surfaces:''' 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 of the entire computational domain. ===

[[In EM.Cube]]'s [[Propagation Module]] allows you to define block groups Terrano, buildings and all other geometric objects are initially drawn on the XY plane. In other words, the Z-coordinates of each the local coordinate system (LCS) of all blocks are set to zero until you change them. Since the above three typesglobal ground is located a z = 0, your buildings are seated on the ground. Each block group When your propagation scene has an irregular terrain, you would want to place your buildings on the same color or texture and its members share surface of the same material properties: permittivity &epsilon;_r terrain and conductivity &sigma;not buried under it. Also, all This can be done automatically as part of the penetrable surfaces belonging to definition of the same block group have the same wall thickness. You can define many different Open the property dialog of a block groups with certain properties group and underneath each introduce many member check the box labeled '''Adjust Block to Terrain Elevation'''. All the objects with different geometrical shapes and dimensionsbelonging to that block are automatically elevated in the Z direction such that their bases sit on the surface of their underlying terrain. The table below summarizes In effect, the characteristics LCS of each block type:of these individual objects is translated along the global Z-axis by the amount of the Z-elevation of the terrain object at the location of the LCS.

{{Note| class="wikitable"|-! scope="col"| Block Type! scope="col"|Physical Effects! scope="col"|Admissible Object Types|-| Impenetrable Surface| ReflectionYou have to make sure that the resolution of your terrain, Diffraction| All Solid &amp; Surface CAD Objects|its variation scale and building dimensions are all comparable. Otherwise, on a rapidly varying high-| Penetrable Surface| Reflectionresolution terrain, Diffraction, Transmission| All Solid &amp; Surface CAD Objects|-| Terrain Surface| Reflection| Tessellated Objects Only|you will have buildings whose bottoms touch the terrain only at a few points and parts of them hang in the air.}}

<table><tr><td> [[FileImage:PROP14(2)PROP MAN6.png|thumb|200pxleft|[[Propagation Module360px|A set of buildings on an undulating terrain without elevation adjustment.]]'s Impenetrable Surface dialog</td><td>[[Image:PROP MAN7.png|thumb|left|360px|The set of buildings on the undulating terrain after elevation adjustment.]] </td></tr></table>

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 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 assumption. [[== EM.Cube]] offers &quot;Impenetrable Blocks&quot; to model buildings in outdoor propagation scenes. A penetrable block has a color or texture property as well as material properties: permittivity (e_r) and conductivity (Terrano's). By default, a brick building is assumed with Ray Domain &epsilon;_r Global Environment = 4.4 and &sigma; = 0.001 S/m. Impinging rays are reflected from the facets of impenetrable buildings or diffracted from their edges.

To define === Why Do You Need a new impenetrable block group, follow these steps:Finite Computational Domain? ===

# Right click on either The SBR simulation engine requires a finite computational domain for ray termination. All the '''Impenetrable Surfaces''' item 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 Navigation Tree and select '''Insert New Blockscene...''' A dialog for setting up the block properties opens up offering When you define a preloaded material type (Brick) propagation scene with predefined color and texturevarious elements like buildings, walls, terrain, etc.# Specify , a name for the block group dynamic domain is automatically established and select displayed as a color or texture.# The electromagnetic model green wireframe box that determines ray-block interaction is selected under '''Specular Interface Type'''surrounds the entire scene. Two options are available: '''Standard Material''' or '''User Defined Model'''. The former Every time you create a new object, the domain box is the default choice automatically adjusted and requires material properties, '''Permittivity''' (&epsilon;_r) and '''Electric Conductivity''' (&sigma;), which are set extended to &quot;Brick&quot; by default. No magnetic properties are allowed for blocks.# Click enclose all the '''OK''' button of objects in the dialog to accept the changes and close itscene.

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

* Open the Ray Domain Settings Dialog by clicking the '''Domain''' [[File:PROP23image025.pngjpg]]button of the '''Simulate Toolbar''', or by selecting '''Menu > Simulate > Computational Domain > Settings...''', or by right-clicking on the '''Ray Domain''' item of the navigation tree and selecting '''Domain Settings...''' from the contextual menu, or simply using the keyboard shortcut {{key|Ctrl+A}}.* The size of the Ray domain is specified in terms of six '''Offset''' parameters along the ±X, ±Y and ±Z directions. The default value of all these six offset parameters is 10 project units. Change these values as you like.* You can also change the color of the domain box using the {{key|Color}} button.* After changing the settings, use the {{key|Apply}} button to make the changes effective while the dialog is still open.

Figure: <table><tr><td> [[Propagation Module]]Image:PROP15.png|thumb|left|480px|EM.Terrano's &quot;Edit Layer&quot; domain settings dialog corresponding to impenetrable surfaces.]]</td></tr></table>

=== Penetrable Surfaces For Indoor Scenes Understanding the Global Ground ===

[[File:PROP15Most outdoor and indoor propagation scenes include a flat ground at their bottom, which bounces incident rays back into the scene. EM.Terrano provides a global flat ground at z = 0. The global ground indeed acts as an impenetrable surface that blocks the entire computational domain from the z = 0 plane downward. It is displayed as a translucent green plane at z = 0 extending downward. The color of the ground plane is always the same as the color of the ray domain. The global ground is assumed to be made of a homogeneous dielectric material with a specified permittivity &epsilon;_r and electric conductivity &sigma;. By default, a rocky ground is assumed with &epsilon;_r = 5 and &sigma; = 0.005 S/m. You can remove the global ground, in which case, you will have a free space scene. To disable the global ground, open up the "Global Ground Settings" dialog, which can be accessed by right clicking on the '''Global Ground''' item in the Navigation Tree and selecting '''Global Ground Settings... '''Remove the check mark from the box labeled '''&quot;Include Half-Space Ground (1z&lt;0).png|thumb|200px|[[Propagation Module]]&quot;'s Penetrable Surface dialog]]'' to disable the global ground. This will also remove the green translucent plane from the bottom of your scene. You can also change the material properties of the global ground and set new values for the permittivity and electric conductivity of the impenetrable, half-space, dielectric medium.

A typical indoor propagation scene usually involves an arrangement of walls that represent the interior of a building. The transmitters and receivers are then placed in the spaces among such walls. From the point of view of [[Alternatively, you can use EM.Cube]]Terrano's SBR simulator, walls act like thin penetrable surfaces. [[EM.Cube]] uses the &quot;Thin Wall Approximation&quot; '''Empirical Soil Model''' to model penetrable surfaces. It assumes that rays simply penetrate a wall and exit at define the same specular point on the opposite side material properties of the wall. In other words, rays are not displaced by the walls, nor do they get trapped inside the walls (no internal reflection)global ground. This is equivalent to assuming model requires a zero thickness for penetrable surfaces for the purpose number of geometrical ray tracing, while the finite thickness of the parameters: Temperature in &quotdeg;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 C, and other structures. You can define many penetrable surface groups with arbitrary thicknesses and material properties (colorVolumetric Water Content, texture, permittivity Sand Content and electric conductivity)Clay Content all as percentage.

{{Note|To define model a new penetrable surface groupfree-space propagation scene, follow these steps:you have to disable EM.Terrano's default global ground.}}

# Right click on one of the '''Penetrable Surfaces''' item in the Navigation Tree and select '''Insert New Block<table><tr><td> [[Image:Global environ.png|thumb|left|720px|EM..''Terrano' A s Global Environment Settings 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.</td># The properties of a penetrable surface are identical to those of an impenetrable surface, 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;<sub/tr>r</subtable> and '''Electric Conductivity''' &sigma;.# Click the '''OK''' button of the dialog to accept the changes and close it.

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

Figure 2: 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 &quot;Edit Layer&quot; dialog corresponding other 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 penetrable surfacesgenerate 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.

You can construct several thin walls and arrange them as roomsEM. A regular room can be built by placing four vertical wall objects together with an optional horizontal wall at the top Terrano provides three radiator types for the ceiling. Alternatively, you may use [[EM.Cube]]'s hollow box objects or boxes with one or two capped end(s). '''Keep in mind that all the penetrable surfaces belonging to a group have the same wall thickness, which is initially set to 0.5 project units by default. Also, note that solid CAD objects belonging to a penetrable surface group are treated as air-filled hollow structures.''' The thickness of penetrable surfaces is implied and not visualized when displaying objects in the project workspace.point transmitter sets:

The SBR simulation engine requires a finite computational domainEM. 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 Terrano also provides three radiator types for point 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 wireframe box with green lines that surrounds the entire scene. Every time you create a new object, the domain is automatically adjusted and extended to enclose all the objects in the scene. You can change the size and color of the domain box through the Ray Domain Settings Dialog, which can be accessed in one of the following three wayssets:

# Click the '''Domain''' [[File:image025.jpg]] button Half-wave dipole oriented along one of the Simulation Toolbar.three principal axes# Select the '''Simulate''' &gt; '''Computational Domain''' &gt; '''Settings...''' item of the Simulate Menu.Polarization-matched isotropic radiator# Right click on the '''Ray Domain''' item of the Navigation Tree and select '''Domain Settings...'''# Use the keyboard shortcut '''Ctrl + A'''.User defined (arbitrary) antenna with imported far-field radiation pattern

The size of the Ray domain is specified in terms of six '''Offset''' [[parameters]] along the ±X, ±Y default transmitter and ±Z directions. The default value of all these six offset [[parameters]] is 10 project units. You can change them arbitrarily. After changing these values, use the '''Apply''' button to make the changes effective while the dialog is still openreceiver radiator types are both vertical (Z-directed) half-wave dipoles.

[[FileThere are three different ways to define a transmitter set or a receiver set:PROP15.png]]

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]] 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 = Defining a translucent green plane at z = 0 extending downward. The color of Point Transmitter Set in 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 Formal Way == 5 and &sigma; = 0.005 S/m. You can remove the global ground, in which case, you will have a free space scene. To disable the global ground, open up the Global Ground Settings Dialog, which can be accessed by right clicking on the '''Global Ground''' item in the Navigation Tree and selecting '''Global Ground Settings... '''Remove the check mark from the box labeled '''&quot;Include Half-Space Ground (z&lt;0)&quot;''' to disable the global ground. This will also remove the green translucent plane from the bottom of your scene. You can also change the material properties of the global ground and set new values for the permittivity and electric conductivity of the impenetrable, half-space, dielectric medium. '''Do not forget to disable the global ground if you want to model a free space propagation scene.'''

[[File:PROP4Transmitters act as sources in a propagation scene.png]]A transmitter is a point radiator with a fully polarimetric radiation pattern defined over the entire 3D space in the standard spherical coordinate system. EM.Terrano gives you three options for the radiator associated with a point transmitter:

=== Terrain Surfaces vsBy default, EM. Global Ground ===Terrano assumes that your transmitter is a vertically polarized (Z-directed) resonant half-wave dipole antenna. This antenna has an almost omni-directional radiation pattern in all azimuth directions. It also has radiation nulls along the axis of the dipole. You can change the direction of the dipole and orient it along the X or Y axes using the provided drop-down list. The second choice of two orthogonally polarized isotropic radiators is an abstract source that is used for polarimetric channel characterization as will be discussed later.

[[File:PROP16You can override the default radiator option and select any other kind of antenna with a more complicated radiation pattern.png|thumb|200px|For this purpose, you have to import a radiation pattern data file to EM.Terrano. You can model any radiating structure using [[Propagation ModuleEM.Cube]]'s Terrain dialogother computational modules, [[EM.Tempo]], [[EM.Picasso]], [[EM.Libera]] or [[EM.Illumina]], and generate a 3D radiation pattern data file for it. The far-field radiation patter data are stored in a specially formatted file with a &quot;'''.RAD'''&quot; file extension. This file contains columns of spherical &phi; and &theta; angles as well as the real and imaginary parts of the complex-valued far-zone electric field components '''E_&theta;''' and '''E_&phi;'''. The &theta;- and &phi;-components of the far-zone electric field determine the polarization of the transmitting radiator.

A terrain surface acts as a custom{{Note|By default, unlevel or irregular ground for your propagation scene. [[EM.Cube]]'s default global ground blocks the z &lt; 0 Terrano assumes a vertical 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 groundwave dipole radiator for your point transmitter set.}}

Terrain objects have some important differences A transmitter set always needs to be associated with an existing base location set with one or more point objects of in the &quot;Impenetrable Surface&quot; type:project workspace. Therefore, you cannot define a transmitter for your scene before drawing a point object under a base location set.

# While impenetrable blocks can be created using any of [[EMImage:Info_icon.Cubepng|40px]]Click here to learn how to define a '''s solid or surface CAD object creation tools, terrain objects are created either using [[EMGlossary_of_EM.Cube%27s_Materials,_Sources,_Devices_%26_Other_Physical_Object_Types#Point_Transmitter_Set | Point Transmitter Set]]'s '''Terrain Generator''' or by importing an external terrain file. # Terrain objects belong to 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 the elevation of other objects or transmitters or receivers that are located above them.

Just as other blocks are grouped by their color, texture and material composition, terrain objects are also grouped in a similar fashion<table><tr><td> [[Image:Terrano L1 Fig11. Before you can generate or import a new terrain object, first you have to define a terrain group and specify its color/texture and material propertiespng|thumb|left|480px|The point transmitter set definition dialog. To define a new terrain group, follow these steps:]] </td></tr></table>

* Right click on Once you define a new transmitter set, its name is added in the '''TerrainTransmitters''' item in section of the Navigation Tree navigation tree. The color of all the base points associated with the newly defined transmitter set changes, and select an additional little ball with the transmitter color (red by default) appears at the location of each associated base point. You can open the property dialog of the transmitter set and modify a number of parameters including the '''Insert New Terrain...Source Power''' A dialog for setting up the terrain properties opens up offering a of preloaded material type (Rock) with predefined green color in Watts and no texture.* Specify a name for the terrain group and select a color broadcast signal '''Phase''' in degrees. The default transmitter power level is 1W or texture30dBm.* Similar to other blocksThere is also a check box labeled '''Use Custom Input Power''', which is checked by default. In that case, the power and phase boxes are enabled and you have to specify can change the material properties, Permittivity (&epsilon;_r) default 1W power and Electric Conductivity (0&sigmadeg;), of the terrain groupphase values as you wish. Rock with [[EM.Cube]]'s ".RAD" radiation pattern files usually contain the value of &epsilonquot;_r = 5 and Total Radiated Power&sigmaquot; = 0in their file header.005 S/m This quantity is calculated based on the default material choice for a new terrainparticular excitation mechanism that was used to generate the pattern file in the original [[EM.Cube]] module.* Click When the '''OK''' button "Use Custom Input Power" check box is unchecked, EM.Terrano will use the total radiated power value of the dialog to accept radiation file for the changes and close itSBR simulation.

You can change the properties {{Note|In order to modify any of a terrain surface group from its property dialog. Click on the table that list the properties transmitter set's parameters, first you need to select and highlight a row. Then, click the '''Add/Edit''' button to open up the &quot;Edit Layer&quot; dialog"User Defined Antenna" option, which is identical even if you want to keep the case of impenetrable surfacesvertical half-wave dipole as your radiator. You can also use [[EM.Cube]]'s Material List, which will be explained later. When a new terrain type is created, its node on the Navigation Tree becomes active. Under this node you can create and add new terrain objects. When a terrain node is active for drawing, all CAD object creation tools are disabled. You have three options for creating a new terrain object, which will be described in detail in the next sections of this manual:}}

# Use <table><tr><td> [[EMFile:NewTxProp.png|thumb|left|720px|The property dialog of a point transmitter set.Cube]]'s '''Terrain Generator'''.# Import an external terrain file of &quot;'''.TRN'''&quot; type.</td># Import an external terrain file of &quot;'''.DEM'''&quot; type.</tr></table>

{{Note| If you do not modify the default parameters of the transmitter chain, a 50-&Omega; conjugate match condition is assumed and the power delivered to the antenna will be -3dB lower than your specified baseband power.}} <table><tr><td> [[File:PROP18NewTxChain.png|thumb|250pxleft|[[Propagation Module]]720px|EM.Terrano's Terrain Generator point transmitter chain dialog.]]</td></tr></table>

[[EM.Cube]] provides === Defining a convenient and powerful Terrain Generator for creating a variety of terrain [[Surface Objects|surface objects]]. [[EM.Cube]]'s Terrain Generator looks very similar to [[CubeCAD]]'s Surface Generator. However, whereas Point Receiver Set in the Surface Generator creates a generic or polymesh surface object, Terrain Generator always creates another special type of object known as a '''Tessellated Object'''. A terrain object is much simpler than [[EM.Cube]]'s polymesh objects and is usually made up of triangular or quadrilateral facets. As such, terrain objects have limited editing capabilities. For example, you can cut, copy, paste, translate or rotate terrain objects. But operations like scaling, mirroring, grouping (composite), arraying, exploding, linking or Boolean operations do not work on terrain objects.Formal Way ===

To create a new terrain object using Terrain Generator, first you need to define a terrain group Receivers act as observables in the Navigation Treea propagation scene. Right click on the name The objective of a SBR simulation is to calculate the terrain node far-zone electric fields and select '''Terrain Generator...''' from the contextual menu. This opens up total received power at the Terrain Generator Dialoglocation of a receiver. Using Terrain Generator, You need to define at least one receiver in the scene before you can build run a single terrain surface or an array of surfaces patched togetherSBR simulation. Some of Similar to a transmitter, a receiver is a point radiator, too. EM.Terrano gives you three options for the available terrain models includeradiator associated with a point receiver set:

# Flat Plane# Hill (Elliptic Quadratic)# Mountain (Elliptic Cone)# 1-D and 2-D Cliff# Gaussian Hump# Undulated Sinusoid# Undulated Sinc# Super* Half-quadratic Plateauwave dipole# Custom Function* Polarization matched isotropic radiator# XY Grid Data* User defined antenna pattern

In all of the above modelsBy default, you can set the height of the surface object to an any desired valueEM.Terrano assumes that your receiver is a vertically polarized (Z-directed) resonant half-wave dipole antenna. You set can change the lateral extents direction of the surface dipole and its resolution orient it along the X and or Y directions in axes using the boxes labeled '''Range Start''', '''Range Stop''' and '''Range Step'''provided drop-down list. The step values along the X An isotropic radiator has a perfect omni-directional radiation pattern in all azimuth and Y elevation directions are a measure of surface smoothness: . An isotropic radiator doesn't exist physically in the smaller the step valuesreal world, but it can be used simply as a point in space to compute the higher the resolution and the smoother the resulting terrain objectelectric field.

Some surface types have an additional shape factor called '''Alpha''' that is identical to the alpha parameter in the surface generator. For example, You may also define a Gaussian Hump is defined as exp(-r²/(2a²)), where r is the polar radiuscomplicated radiation pattern for your receiver set. For a Super-quadratic HumpIn that case, the input parameter a defines the degree of the super-quadratic surface. you need to import a = 2 corresponds radiation pattern data file to an ellipsoidEM. Larger values of a get close Terrano similar to a rectangular base with rounded corners. An undulated sinusoidal surface is defined by cos(pax/D_x)*cos(pay/D_y), and an undulated sinc is defined by D_x*D_y*sin(pax/D_x)*sin(pay/D_x)/(2pxy), where D_x and D_y are the X and Y dimensions, respectively. Terrain Generator creates case of a unit cell based on the specified surface type. From the same dialog, you can also produce an array arrangement of such unit cells. Simply enter any number of elements along the X and Y directions in the boxes labeled '''Array'''transmitter set.

[[File:PROP19.png{{Note|800px]] By default, EM.Terrano assumes a vertical half-wave dipole radiator for your point receiver set.}}

Figure: 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 4 × 4 typical propagation scene contains one or few transmitters but usually a large number of receivers. To generate a wireless coverage map, you need to define an array of hill terrain objectspoints as your base location set.

You can define any arbitrary surface by entering an equation of the two [[variablesImage:Info_icon.png|40px]] x and y as z = f(x,y). In this case, you have Click here to select the learn how to define a '''Custom Function''' option in the dropdown list labeled '''Model'''. You should enter your equation as any mathematical expression in the box labeled '''Function f(x,y)'''. You can use any of EM[[Glossary_of_EM.Cube%27s_Simulation_Observables_%26_Graph_Types#Point_Receiver_Set | Point Receiver Set]]'s mathematical functions listed in the '''Function Dialog''' or combine several of them. Note that after selecting the custom function option, the height of the surface is determined by your equation, and the '''Height''' box is disabled. You can also introduce random noise and create a rough terrain. You can do this by setting a nonzero value for '''Noise''', which represent the RMS peak-to-valley amplitude of the surface roughness. The figures below show two custom terrain surfaces modeled by the equation z = (x.y)/20 defined over the range [0, 10] in both X and Y directions. Random noise has been added to both surfaces, with the noise amplitude being 0.2 and 0.5 for the left and right figures, respectively.

<table><tr><td> [[FileImage:PROP21Terrano L1 Fig12.png|400px]] [[File:PROP20thumb|left|480px|The point receiver set definition dialog.png|400px]]</td></tr></table>

Figure: Two noisy custom terrain surfaces both Once you define a new receiver set, its name is added to the '''Receivers''' section of the navigation tree. The color of all the base points associated with the newly defined as z = (x.y)/20: (Left) RMS noise amplitude = 0.2receiver set changes, and an additional little ball with the receiver color (rightyellow by default) RMS noise amplitude = 0appears at the location of each associated base point.5You can open the property dialog of the receiver set and modify a number of parameters.

Every time you create a new terrain object using Terrain GeneratorIn the Receiver Set dialog, an ASCII data file named &quot;GeneratedTerrain&quot; with there is a &quot;drop-down list labeled '''.TRNSelected Element'''&quot; file extension is created and placed in your project folder. This is [[EM.Cube]]'s simple native terrain file format that basically lists all the (x, y, z) coordinates which contains a list of all the generated surface points on a horizontalindividual receivers belonging to the receiver set. At the end of an SBR simulation, rectangular XY gridthe button labeled {{key|Show Ray Data}} becomes enabled. Terrain Generator simply takes your custom function definition or one Clicking this button opens the Ray Data dialog, where you can see a list of all the received rays at the selected catalog surface types receiver and generates the digital elevation data on the specified gridtheir computed characteristics.

Another type If you choose the "user defined antenna" option for your receiver set, it indeed consists of terrain model a basic "Receiver Chain" that contains a receive antenna connected via a segment of transmission line to the terrain generator provides low-noise amplifier (LNA) that is terminated in a matched load. The receiver set'''XY Grid Data'''s property dialog allows you to define the basic receiver chain. In this caseClick the {{key|Receiver Chain}} button of the Receiver Set dialog to open the receiver chain dialog. As shown in the figure below, you define a rectangular XY grid with a uniform grid cell size along can specify the X characteristics of the LNA such as its gain and Y directions and manually define noise figure in dB as well as the Z-elevation for each grid point. This is similar characteristics of the transmission line segment that connects the antenna to the surface generator's &quot;2D Uniform Grid&quot; model type in [[CubeCAD]]LNA. Based on your input Note that the receiving antenna characteristics are automatically filled from using contents of the radiation file. You have to enter values for antenna's ''Range Start''', '''Range StopBrightness Temperature''' as well as the temperature of the transmission line and the receiver's ambient temperature. The effective ''Range Step'Receiver Bandwidth'' along X and Y' is assumed to be 100MHz, a 2D grid is set up and displayed in a table at which you can change for the bottom purpose of the terrain generator noise calculations. The Receive Chain dialogcalculates and reports the "Noise Power" and "Total Receiver Chain Gain" based on your input. By defaultAt the end of an SBR simulation, all the Zreceiver power and signal-elevations noise ratio (SNR) of the selected receiver are calculated and they are reported in the receiver set to zero initiallydialog in dBm and dB, respectively. You can click on each table cell and overwrite it with a new value. At examine the end, click the '''Create''' button properties of all the dialog to add individual receivers and all the new gridindividual rays received by each receiver in your receiver set using the "Selected Element" drop-based terrain object to the Navigation Treedown list.

<table><tr><td> [[File:terrain10_tnNewRxChain.png|thumb|left|720px|EM.Terrano's point receiver chain dialog.]]</td></tr></table>

You can import two types of terrain in [[EM*OOK*M-ary ASK*Coherent BFSK*Coherent QFSK*Coherent M-ary FSK*Non-Coherent BFSK*Non-Coherent QFSK*Non-Coherent M-ary FSK*BPSK*QPSK*Offset QPSK*M-ary PSK*DBPSK*pi/4 Gray-Coded DQPSK*M-ary QAM*MSK*GMSK (BT = 0.Cube]]'s [[Propagation Module]]. 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, z3) coordinates of the terrain points are then listed one point per line. The other type of terrain format supported by [[EM.Cube]] is the standard '''7.5min DEM''' file format with a '''.DEM''' file extension.

To import an external terrain modelIn the above list, first you have need to create a terrain group node in specify the Navigation Tree. Right click on the name of the terrain group in the Navigation Tree and select either '''Import Terrain..No.Levels (M)''' or for the Mary modulation schemes, from which the '''Import DEM File..No.Bits per Symbol''' A standard [[Windows]] '''Open Dialog''' opens up, with the file type set to .TRN or .DEM extensions, respectivelyis determined. You can browse your folders and find also define a bandwidth for the right terrain model file to importsignal, which has a default value of 100MHz. Once the SNR of the signal is found, given the specified modulation scheme, the E_b/N₀ parameter is determined, from which the bit error rate (BER) is calculated.

You can also export all the terrain objects in the project workspace as a terrain file with a '''.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 terrain, select '''File''' &gt; '''Export...''' from [[Propagation Module]]'s '''File Menu'''. The standard [[Windows]] Save Dialog opens up with the default file type set to '''.TRN'''. Type in a name for your new terrain file and click the '''Save''' button to export Shannon – Hartley Equation estimates the terrain data.channel capacity:

Figur: An imported external terrain modelwhere B in the bandwidth in Hz, and C is the channel capacity (maximum data rate) expressed in bits/s.

Most of the time, your outdoor propagation scene consists of simple buildings made of single-layer walls with standard material properties (&epsilon;The quantity E_rb and &sigma;). In the case of a single-layer impenetrable surface, the specular interface is an infinite dielectric half-space, which reflects the impinging rays. Single-layer penetrable surfaces, on the other hand, involve finite-thickness dielectric walls, which both reflect and transmit the incident rays. Similarly, most of your indoor propagation scenes involve simple single-layer penetrable walls with the specified material properties &epsilon;/N_r0 and &sigma;is the ratio of energy per bit to noise power spectral density. A thin wall acts like It is a finite-thickness dielectric slab that both reflects measure of SNR per bit and transmits incident rays. In is calculated from the case of the global ground or terrain objects, only ray reflection off the ground surface is considered.following equation:

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 '''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;<submath>r\frac{E_b}{N_0} = \frac{ 2^\eta - 1}{\eta} </submath> 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.

You can also search [[EM.Cube]]'s material database by clicking the '''Material''' button of where &quoteta;Add Layer&quot; or &quot;Edit Layer&quot; dialogs. This opens the '''Materials''' Dialog. Inside the material list select and highlight any row and click the '''OK''' button. The selected material will fill out all the fields in the &quot;Add Layer&quot; or &quot;Edit Layer&quot; dialogs. Inside the Materials Dialog, you can type the few first letters of any material, and it will take you to the corresponding row of is the listspectral efficiency.

[[File:PROP24The relationship between the bit error rate and E_b/N₀ depends on the modulation scheme and detection type (coherent vs.png]]non-coherent). For example, for coherent QPSK modulation, one can write:

Figure<math> P_b = 0.5 \; \text{erfc} \left( \sqrt{ \frac{E_b}{N_0} } \right) </math> where P_b is the bit error rate and erfc(x) is the complementary error function: [[EM.Cube]]'s material list.

<math> \text{erfc}(x) =1-\text{erf}(x) == Transferring Objects From Or To Other Modules ===\frac{2}{\sqrt{\pi}} \int_{x}^{\infty} e^{-t^2} dt </math>

When you start a new project in [[EM.Cube]]The '''Minimum Required SNR'''s [[Propagation Module]] and draw a solid object like a box in the project workspace without having defined any surface groups, it parameter is assumed used to be of the impenetrable surface type. A default impenetrable surface group called Block_1 is automatically added 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 determine link connectivity between each transmitter and &sigma; = 0receiver pair.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 If you can define a new surface type with different properties. By default, check the last surface group that was defined is box labeled '''ActiveGenerate Connectivity Map'''. The current active surface group is always listed in bold letters in the Navigation Tree. When you draw receiver set property dialog, a new object, it binary map of the propagation scene is always inserted under the current active surface groupgenerated by EM. Any surface group can be activated by right clicking its name Terrano, in the Navigation Tree which one color represents a closed link and selecting another represent no connection depending on the selected color map type of the graph. EM.Terrano also calculates the '''ActivateMax Permissible BER''' item of corresponding to the specified minimum required SNR and displays it in the contextual menureceiver set property dialog.

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

Like every other electromagnetic solver<math> E_\theta(\theta, \phi) \approx j\eta_0 I_0 \frac{e^{-jk_0 r}}{2\pi r} \left[[EM.Cube]]'s SBR ray tracer requires a source for excitation and one or more observables for generation of simulation data. [[EM.Cube]]'s new [[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] 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: </math>

There are four types where k₀ = 2&pi;/&lambda;₀ is the free-space wavenumber, &lambda;₀ is the free-space wavelength, &eta;₀ = 120&pi; &Omega; is the free-space intrinsic impedance, I₀ is the current on the dipole, and L is the length of observables:the dipole.

The simplest SBR simulation can be performed using a short dipole source with a specified field sensor plane. In this way, [<math> D_0 \approx \frac{2}{F_1(k_0L) + F_2(k_0L) + F_3(k_0L)} \left[EM.Cube]] computes the electric and magnetic fields radiated by your dipole source in the presence of your multipath propagation environment. A &quot;classic&quot; urban propagation scene can be set up using a &quot;Transmitter&quot; source and an array of &quot;Receiver&quot; observables. A transmitter is a point radiator with a user defined radiation pattern. A receiver is a polarization\frac{\text{cos} \left( \frac{k_0 L}{2} \text{cos} \theta \right) -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. \text{cos} \left( \frac{k_0 L}{2} \right) }{\text{sin}\theta} \right]^2 <br /math>

[[File:PROP18<math> F_1(1x).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 purpose. = \gamma + \text{ln}(x) - C_i(x) </math>

To define a new Transmitter Set, go to the '''Sources''' section of the Navigation Tree, <math> F_2(x) = \frac{1}{2} \text{sin}(x) \left[ S_i(2x) - 2S_i(x) \right click on the '''Transmitters''' item and select '''Insert Transmitter...''' A dialog opens up that contains a default name for the new Transmitter Set as well as a dropdown list labeled '''Select Base Set'''. In this list you will see all the available base sets already defined in the project workspace. Select the desired base set to associate with the transmitter set. Note that if the base set contains more than one point, then more than one transmitter will be created and contained in your transmitter set. After defining a transmitter set, the base points change their color to the transmitter color, which is red by default.] </math>

In the &quot;Radiator&quot; section of the dialog, you have two options to choose from: &quot;Short Dipole&quot; and &quot;User Defined&quot;. The default option is short dipole. A short dipole radiator has a '''Length'''''dl'' expressed in project units, a current '''Amplitude''' in Amperes and a current '''Phase''' in degrees. The '''Direction''' of the dipole is determined by its unit vector that has three X, Y and Z components. By default, a Z<math> F_3(x) = \frac{1}{2} \text{cos}(x) \left[ \gamma + \text{ln}(x/2) + C_i(2x) -directed short dipole radiator is assumed. You can change all [[parameters]2C_i(x) \right] 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>

[[File:PROP1where &gamma; = 0.png|thumb|[[Propagation Module]]'s Base Set dialog]]In order to tie up transmitters and receivers with CAD objects in 5772 is the project workspaceEuler-Mascheroni constant, [[EM.Cube]] uses point objects to define transmitters and receivers. These point objects represent the base of the location of transmitters C_i(x) and receivers in the computational domain. Hence, they S_i(x) are grouped together as &quot;Base Sets&quot;. You can easily interchange the role of transmitters cosine and receivers in a scene by switching their associated bases. The usefulness of concept of base sets will become apparent later when you place transmitters or receivers on an irregular terrain and adjust their elevation. sine integrals, respectively:

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 is initially drawn on the XY plane. Make sure to change the Z-coordinate of your radiator, otherwise, it will fall on the global ground at z = 0. You can also create arrays of base points under the same base set. This is particularly useful for setting up receiver grids to compute coverage maps. Simply select a point object and click the '''Array Tool''' of '''Tools Toolbar''' or use the keyboard shortcut &quot;A&quot;. Enter values for the X, Y or Z spacing as well as the number of elements along these three directions in the Array Dialog. In most propagation scenes you are interested in 2D horizontal arrays along a fixed Z coordinate <math> S_i(parallel to the XY planex).= \int_{0}^{x} \frac{ \text{sin} \tau}{\tau} d\tau </math>

A short dipole is In the closest thing to an omnicase of a half-directional radiator. The direction or orientation of the short wave 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 L = &quotlambda;'''.RAD'''&quot; extension₀/2, which contains columns of spherical &phi; and &theta; angles as well as the real and imaginary parts of the complex-valued far field components '''ED_&theta;0''' and '''E= 1.643. Moreover, the input impedance of the dipole antenna is Z_&phi;A'''= 73 + j42. The 5 &thetaOmega;- and . These dipole radiators are connected via 50&Omega; transmission lines to a 50&phiOmega;-components source or load. Therefore, there is always a certain level of impedance mismatch that violates the far-zone electric field determine the polarization of the transmitting radiatorconjugate match condition for maximum power.

To define a directional transmitter radiator, you need to select the &quot;User Defined&quot; option in the &quot;Radiator&quot; section of the Transmitter Dialog. You can do this either at the time of creating a transmitter set, or afterwards by opening the property dialog of the transmitter set. In the &quot;Custom Pattern <table><tr><td> [[Parameters]]&quot;, click the '''Import Pattern''' button to set the path for the radiation data fileFile:Dipole radiators. 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 simulationpng|thumb|720px|EM. However, you can check the box labeled &quot;Terrano'''Custom Power'''&quot; s native half-wave dipole transmitter and enter a value for the transmitter power in Watts. [[EMreceiver.Cube]] can also rotate the imported radiation pattern arbitrarily. In this case, you need to specify the '''Rotation''' angles in degrees about the X-, Y- and Z-axes. Note that these rotations are performed sequentially and in order: first a rotation about the X-axis, then a rotation about the Y-axis, and finally a rotation about the Z-axis. </td></tr></table>

[[File:PROP19On the other hand, we you specify a user-defined antenna pattern for the transmitter or receiver sets, you import a 3D radiation pattern file that contains all the values of E_&theta; and E_&phi; for all the combinations of (1&theta;, &phi;)angles.pngBesides the three native dipole radiators, [[EM.Cube]] also provides 3D radiation pattern files for three X-, Y- and Z-polarized half-wave resonant dipole antennas. These pattern data were generated using a full-wave solver like [[File:PROP20(1)EM.pngLibera]]'s wire MOM solver. The names of the radiation pattern files are:

Figure 1: [[Propagation Module]]'s Transmitter dialog with a user defined radiator selected* DPL_STD_X.RAD* DPL_STD_Y.RAD* DPL_STD_Z.RAD

=== Multiple Transmitters vsand they are located in the folder "\Documents\EMAG\Models" on your computer. Note that these are full-wave simulation data and do not involve any approximate assumptions. To use these files as an alternative to the native dipole radiators, you need to select the '''User Defined Antenna Arrays ===Pattern''' radio button as the the radiator type in the transmitter or receiver set property dialog.

[[EM.Cube]]'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 === A Note on the principle Rotation 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.Antenna Radiation Patterns ===

If that radiators are indeed the elements of EM.Terrano's Transmitter Set dialog and Receiver Set dialog both allow you to rotate an actual antenna array with a half wavelength spacing or so, we recommend imported radiation pattern. In that case, you import need to specify the radiation pattern of '''Rotation''' angles in degrees about the array structure instead X-, Y- and replace the whole multiZ-radiator system with a single point transmitting radiator in your propagation sceneaxes. This case It is usually encountered in MIMO systems, important to note that these rotations are performed sequentially and using an equivalent point transmitter is an acceptable approximation because in the total size of following order: first a rotation about the array aperture is usually much smaller than X-axis, then a rotation about the dimensions of your propagation scene Y-axis, and its representative length scalesfinally a rotation about the Z-axis. In that caseaddition, you need all the rotations are performed with respect to position the equivalent point radiator at "rotated" local coordinate systems (LCS). In other words, the radiation center of first rotation with respect to the antenna arraylocal X-axis transforms the XYZ LCS to a new primed X^&prime;Y^&prime;Z^&prime; LCS. This depends on The second rotation is performed with respect to the physical structure of new Y^&prime;-axis and transforms the antenna array. However, keep in mind that any reasonable guess may still provide X^&prime;Y^&prime;Z^&prime; LCS to a good approximation without any significant error in new double-primed X^{&prime;&prime;}Y^{&prime;&prime;}Z^{&prime;&prime;} LCS. The third rotation is finally performed with respect to the received ray datanew Z^{&prime;&prime;}-axis. The figures below shows single and double rotations.

Receivers act as observables in a propagation scene. The objective === Adjustment of Tx/Rx Elevation above 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, 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. Terrain Surface ===

To define When your transmitters or receivers are located above a new Receiver Setflat terrain like the global ground, go their Z-coordinates are equal to their height above the Observables section of the Navigation Treeground, right click on as the '''Receivers''' item terrain elevation is fixed and select '''Insert Receiverequal to zero everywhere...''' A dialog opens up that contains a default name for In many propagation modeling problems, your transmitters and receivers may be located above an irregular terrain with varying elevation across the new Receiver Set as well as a dropdown list labeled '''Select Radiator Set'''scene. In this list you will see all the available base sets that case, you have already define in may want to place your transmitters or receivers at a certain height above the project workspaceunderlying ground. Select and designate The Z-coordinate of a transmitter or receiver is now the desired base set as sum of the receiver set. Note that if terrain elevation at the base set contains more than one point, all of them are designated as receiversand the specified height. After defining a receiver set, EM.Terrano gives you the points change their color option to adjust the transmitter and receiver color, which sets to the terrain elevation. This is yellow by defaultdone for individual transmitter sets and individual receiver sets. The first element of At the set is represented by a larger ball top of the same color indicating that it is the selected receiver in the scene. The Receiver Set Transmitter Dialog there is also used a check box labeled &quot;'''Adjust Tx Sets to access individual receivers of the set for data visualization Terrain Elevation'''&quot;. Similarly, at the end top of a simulation. At the end of an SBR simulation, the button Receiver Dialog there is a check box labeled &quot;Show Ray Data'''Adjust Rx Sets to Terrain Elevation'''&quot; becomes enabled. Clicking this button opens the Ray Data DialogThese boxes are unchecked by default. As a result, where your transmitter sets or receiver sets coincide with their associated base points in the project workspace. If you can see check these boxes and place a list of all transmitter set or a receiver set above an irregular terrain, the received rays at transmitters or receivers are elevated from the selected receiver and location of their computed characteristicsassociated base points by the amount of terrain elevation as can be seen in the figure below.

[[File:PROP21To better understand why there are two separate sets of points in the scene, note that a point array (1CAD object)is used to create a uniformly spaced base set.png]] [[File:PROP22The array object always preserves its grid topology as you move it around the scene. However, the transmitters or receivers associated with this point array object are elevated above the irregular terrain and no longer follow a strictly uniform grid. If you move the base set from its original position to a new location, the base points' topology will stay intact, while the associated transmitters or receivers will be redistributed above the terrain based on their new elevations.png]]

Figure 1: <table><tr><td> [[Propagation ModuleImage:PROP MAN8.png|thumb|left|640px|A transmitter (red) and a grid of receivers (yellow) adjusted above a plateau terrain surface. The underlying base point sets (blue and orange dots) associated with the adjusted transmitters and receivers on the terrain are also visible in the figure.]]'s Receiver dialog.</td></tr></table>

=== Defining Field Sensors =Discretizing the Propagation Scene in EM.Terrano ==

[[File:PMOM90.png|thumb|[[Propagation Module]]'s Field Sensor dialog]]As an asymptotic electromagnetic field solver, the SBR simulation engine can compute the electric and magnetic field distributions in a specified plane. In order === Why Do You Need to view these field distributions, you must first define field sensor observables before running the SBR simulation. To do that, right click on the '''Field Sensors''' item in the '''Observables''' section of the Navigation Tree and select '''Insert New Observable...'''. The Field Sensor Dialog opens up. At the top of the dialog and in the section titled '''Sensor Plane Location''', first you need to set the plane of field calculation. In the dropdown box labeled '''Direction''', you have three options X, Y, and Z, representing the&quot;normals&quot; to the XY, YZ and ZX planes, respectively. The default direction is Z, i.e. XY plane parallel to the substrate layers. In the three boxes labeled '''Coordinates''', you set the coordinates of the center of the plane. Then, you specify the '''Size''' of the plane in project units, and finally set the '''Number of Samples''' along the two sides of the sensor plane. The larger the number of samples, the smoother Discretize the near field map will appear. Scene? ===

In the section titled Output Settings, you can also select the field map type from two options: '''Confetti''' and '''Cone'''EM. 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 Terrano'''Data Interpolation''', which creates s SBR solver uses a smooth and blended method known as Geometrical Optics (digitally filteredGO) map. In in conjunction with the cone case, you can set the size Uniform Theory of Diffraction (UTD) to trace the vector cones that represent rays from their originating point at the field direction. At the end of a sweep simulation, multiple field map are produced and added source to the Navigation Treeindividual receiver locations. You can animate these maps. HoweverRays may hit obstructing objects on their way and get reflected, during the sweep only one field type is stored, either the E-field diffracted or H-fieldtransmitted. You EM.Terrano's SBR solver can choose only handle diffraction off linear edges and reflection from and transmission through planar interfaces. When an incident ray hits the field type for multiple plots using surface of the radio buttons in obstructing object, a local planar surface assumption is made at the section titled '''Field Display - Multiple Plots'''specular point. The default choice is assumptions of linear edges and planar facets obviously work in the E-fieldcase of a scene with cubic buildings and a flat global ground.

Once In many practical scenarios, however, your buildings may have curved surfaces, or the terrain may be irregular. EM.Terrano allows you close the Field Sensor dialogto draw any type of surface or solid geometric objects such as cylinders, its name is added cones, etc. under the impenetrable and penetrable surface groups or penetrable volumes. EM.Terrano'''Field Sensors''' node s mesh generator creates a triangular surface mesh of all the Navigation Treeobjects in your propagation scene, which is called a facet mesh. At Even the end walls of a SBR simulation, the field sensor nodes in the Navigation Tree become populated by the magnitude and phase plots cubic buildings are meshed using triangular cells. This enables EM.Terrano to properly discretize composite buildings made of the three vectorial components of the electric ('''E''') and magnetic ('''H''') field as well as the total electric and magnetic fields defined in the following manner:conjoined cubic objects.

:<math> \mathbf{|H_{tot}|} = \sqrt{|H_x|^2 + |H_y|^2 + |H_z|^2} </math><!--[[File:PMOM88.png]]-->== Generating the Facet Mesh ===

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

Coming Soon<table><tr><td> [[Image:prop_manual-29.png|thumb|left|480px|EM.Terrano's mesh settings dialog.]] </td></tr></table>

In a typical SBR simulation, a ray is traced from the location of the source until it hits a scatterer. The <table><tr><td> [[SBR MethodImage:UrbanCanyon2.png|thumb|left|SBR method]] assumes that the ray hits either a flat 640px|The facet mesh of the scatterer or one of its edgesbuildings in the urban propagation scene generated by EM. In the case Terrano's Random City wizard with a cell edge length of hitting a flat facet, the specular point is used to launch new reflected and transmitted rays100m. ]] </td></tr><tr><td> [[Image:UrbanCanyon3.png|thumb|left|640px|The surface facet mesh of the facet is treated as an infinite dielectric medium interface, at which the reflection and transmission coefficients are calculated. In the case of hitting an edge, new diffracted rays are generated buildings in the urban propagation scenegenerated by EM. However, only those who reach Terrano's Random City wizard with a nearby receiver in their line cell edge length of sight are ever taken into account. In other words, diffractions are treated locally10m.]] </td></tr></table>

[[EM.Cube]]'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 non-flat surfaces have to be discretized == Running Ray Tracing Simulations in the form of a collection of smaller flat facets. [[EM.Cube]] uses a triangular surface mesh generator to discretize the penetrable and impenetrable [[Surface Objects|surface objects]] of your propagation scene. This mesh generator is very similar to the ones used in [[EM.Cube]]'s two other modules: MoM3D and Physical Optics (PO). Terrano ==

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

=== Viewing * 3D Field Solver* SBR Mesh ===Channel Analyzer* Log-Haul Channel Analyzer* Communication Link Solver* Radar Link Solver

You can view and examine the discretized version of your scene objects as they The first three simulation types are sent to the SBR simulation enginedescribed below. To view the mesh, click the '''Mesh''' [[File:mesh_tool.png]] button For a description of the Simulate Toolbar or select '''Simulate &gt; Discretization &gt; Show Mesh''', or use the keyboard shortcut '''Ctrl+M'''. A triangular surface mesh of your physical structure appears in the project workspace. In this case, [[EM.Cube]] enters it mesh view mode. You can perform view operations like rotate view, pan, zoom, etc. But you cannot select objects, or move them or edit their properties. To get out of the Mesh View and return to [[EM.Cube]]Terrano's Normal ViewRadar Simulator, press the '''Esc Key''' of the keyboard, or click the Mesh button of the Simulate Toolbar once again, or go to the Simulate Menu and deselect the '''Discretization &gt;''' '''Show Mesh''' itemfollow this link.

You can adjust the mesh resolution and increase the geometric fidelity of discretization by creating more and finer triangular facets. On the other hand, you may want to reduce the mesh complexity and send to the === Running a Single-Frequency 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.Analysis ===

Note that unlike [[EM.Cube]]'s other computational modules that express the default mesh density based on the wavelength, the resolution of Its main solver is the '''3D SBR mesh generator is expressed Ray Tracer'''. Once you have set up your propagation scene in project length unitsEM. The default edge length value of 100 units might be too large Terrano and have defined sources/transmitters and observables/receivers for non-flat objectsyour scene, you are ready to run a SBR ray tracing simulation. You may have to use set the simulation mode in EM.Terrano's simulation run dialog. A single-frequency SBR analysis is a lower value to capture single-run simulation and the curvature simplest type of your curved structures adequatelyray tracing simulation in EM. Terrano. It involves the following steps:

[[File:prop_manual-29* 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 project unit.* 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 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.png]]

Figure 1: You can access EM.Terrano's Simulation Run dialog by clicking the '''Run''' [[Propagation ModuleFile:run_icon.png]]button of the 's Mesh Settings dialog''Simulate Toolbar''' or by selecting '''Simulate &rarr; Run...''' or using the keyboard shortcut {{key|Ctrl+R}}. When you click the {{key|Run}} button, a new window opens up that reports the different stages of the SBR simulation and indicates the progress of each stage. After the SBR simulation is successfully completed, a message pops up and prompts the completion of the process.

In <table><tr><td> [[EMImage:PROP MAN10.Cube]], terrain objects are represented by and saved as special &quot;Tessellated&quot; objects with quadrilateral cells. This is true of terrain objects that you create yourself using [[png|thumb|left|550px|EM.Cube]]Terrano's Terrain Generator as well as all the terrain objects that you import from external files to your projectoutput message window. The center of each cell represents the terrain elevation at that point. Tessellated objects are considered as discretized objects by [[EM.Cube]] and they are not meshed one more time by the SBR mesh generator. Each quadrilateral cell is divided into two triangular cells before being passed to the SBR simulation engine. Therefore, when using [[EM.Cube]]'s Terrain Generator to create a new terrain object, you have to pay special attention to the resolution of the terrain object as it determines the total number of terrain facets sent to the simulation engine. A high resolution terrain, although looking better and more realistic, may easily lead to an enormous computational problem.</td></tr></table>

You can use [[EM.Cube]]'s &quot;Polymesh&quot; tool to discretize solid and surface CAD objects. You can manually control the mesh characteristics of polymesh objects including inserting new nodes 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 are also considered as discretized objects by [[EM.Cube]] and they are not meshed again by === Changing the SBR mesh generator. Engine Settings ===

=== There are a number of SBR Mesh Rules &amp; Considerations ===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 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.

Coming SoonEM.Terrano allows a finite number of ray bounces for each original ray emanating from a transmitter.This is very important in situations that may involve resonance effects where rays get trapped among multiple surfaces and may bounce back and forth indefinitely.This is set using the box labeled &quot;'''Max No. Ray Bounces'''&quot;, which has a default value of 10. Note that the maximum number of ray bounces directly affects the computation time as well as the size of output simulation data files. This can become critical for indoor propagation scenes, where most of the rays undergo a large number of reflections. Two other parameters control the diffraction computations: '''Max Wedge Angle''' in degrees and '''Min Edge Length''' in project units. The maximum wedge angle is the angle between two conjoined facets that is considered to make them almost flat or coplanar with no diffraction effect. The default value of the maximum wedge angle is 170&deg;. The minimum edge length is size of the common edge between two conjoined facets that is considered as a mesh artifact and not a real diffracting edge. The default value of the minimum edge length is one project units.

In [[EMAs rays travel in the scene and bounce from surfaces, they lose their power, and their amplitudes gradually diminish.Cube]]From a practical point of view, only rays that have power levels above the receiver sensitivity can be effectively received. Therefore, buildings and all other CAD objects the rays whose power levels fall below a specified power threshold are initially created on the XY plane by discarded. The '''Ray Power Threshold''' is specified in dBm and has a defaultvalue of -150dBm. In other words, Keep in mind that the Z-coordinate value of this threshold directly affects the local coordinate system (LCS) accuracy of all blocks is set to zero until you change them. As long as you use the global ground, all is fine simulation results as well as your buildings are seated on the ground. When your propagation scene has an irregular terrain, you want to place your buildings on size of the terrain and not buried under it. Buildings in [[EM.Cube]] are not adjusted to the terrain elevation automatically. You need to instruct [[EM.Cube]] to do sooutput data file.

To update the building positions and adjust their elevation to the underlying terrain, right click on You can also set the '''TerrainRay Angular Resolution''' item of the Navigation Tree and select 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 '''Adjust Scene ElevationRecommended Ray Angular Resolution''' from the context menu. All the blocks in the scene are automatically elevated degrees in the Z direction such that their bases sit a grayed-out box. This number is calculated based on the terrain. In effect, all the blocks are translated along the global Z axis by proper amounts such that their local Z coordinate equals the Z-elevation overall extents of your computational domain as well as the underlying terrain objectSBR mesh resolution. This feature is particularly useful if To see this value, you change have to generate the location SBR mesh first. Keeping the angular resolution of your project above this threshold value makes sure that the terrain or import a new terrain after small mesh facets at very large distances from the blocks have been createdsource would not miss any impinging ray tubes during the simulation.

Note: You have to make sure that EM.Terrano gives a few more options for the resolution ray tracing solution of your terrain, its fluctuation scale and building dimensions are all comparablepropagation problem. OtherwiseFor instance, on a highit allows you to exclude the direct line-resolution, rapidly varying terrainof-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 will have buildings whose bottoms are in contact with to superpose the terrain only at a few points and parts received rays incoherently. In that case, the powers of them hang individual ray are simply added to compute that total received power. This option in the aircheck box labeled "Superpose rays incoherently" is disabled by default, too.

[[File:prop_adjust1_tnAt the end of a ray tracing simulation, the electric field of each individual ray is computed and reported.png|400px]] [[File:prop_adjust2_tnBy default, the actual received ray fields are reported, which are independent of the radiation pattern of the receive antennas.png|400px]]EM.Terrano provides a check box labeled "Normalize ray's E-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:

In many propagation modeling problemsa 3D SBR simulation, 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 groundtransmitter shoots a large number of rays in all directions. The Z-coordinate electric fields of a transmitter or receiver is now these rays are polarimetric and their strength and polarization are determined by the sum designated radiation pattern of the terrain elevation at transmit antenna. The rays travel in the base point propagation scene and bounce from the specified height. [[EM.Cube]] gives you ground and buildings or other scatterers or get diffracted at the option to adjust building edges until they reach the transmitter and receiver sets to location of the terrain elevationreceivers. This is done for Each individual transmitter sets ray has its own vectorial electric field and individual receiver setspower. At the top The electric fields of the Transmitter Dialog there is a check box labeled &quot;'''Adjust Tx Sets received rays are then superposed coherently and polarimetrically to Terrain Elevation'''&quot;. Similarly, compute the total field at the top receiver locations. The designated radiation pattern of the Receiver Dialog there receivers is a check box labeled &quot;'''Adjust Rx Sets then used to Terrain Elevation'''&quot;. These boxes are unchecked compute the total received power by default. As a result, your transmitter sets or each individual receiver sets coincide with their associated base points in the project workspace. If you check these boxes and place a transmitter set or a receiver set above an irregular terrain, the transmitters or receivers are elevated from the location of their associated base points by the amount of terrain elevation as can be seen in the figure below.

To better understand why there From a theoretical point of view, the radiation patterns of the transmit and receive antennas are two separate sets independent of points in the scene, note that a point array (CAD object) is used to create a uniformly spaced base setpropagation channel characteristics. The array object always preserves its grid topology as you move it around For the scene. However, given locations of the point transmitters or and receivers associated with this point array object are elevated above the irregular terrain , one can assume ideal isotropic radiators at these points and no longer follow a strictly uniform gridcompute the polarimetric transfer function matrix of the propagation channel. If you move This matrix relates the base set from its original position received electric field at each receiver location to a new the transmitted electric field at each transmitter location. In general, the base points' topology will stay intactvectorial electric field of each individual ray is expressed in the local standard spherical coordinate system at the transmitter and receiver locations. In other words, while the polarimetric channel matrix expresses the '''E_&theta;''' and '''E_&phi;''' field components associated transmitters or receivers will be redistributed above with each ray at the terrain based on their new elevationsreceiver 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.

[[File:prop_txrx1_tnTo perform a polarimatric channel characterization of your propagation scene, open EM.png|400px]] [[File:prop_txrx2_tnTerrano's Run Simulation dialog and select '''Channel Analyzer''' from the drop-down list labeled '''Select Simulation or Solver Type'''. At the end of the simulation, a large ray database is generated with two data files called "sbr_channel_matrix.DAT" and "sbr_ray_path.DAT". The former file contains the delay, angles of arrival and departure and complex-valued elements of the channel matrix for all the individual rays that leave each transmitter and arrive at each receiver. The latter file contains the geometric aspects of each ray such as hit point coordinates.png|400px]]

== Running A SBR After EM.Terrano's channel analyzer generates a ray database that characterizes your propagation channel polarimetrically for all the combinations of transmitter and receiver locations, a ray tracing solution of the propagation problem can 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.

[[EM.Cube]]'s [[Propagation Module]] offers three types Using the Polarimatrix solver can lead to a significant reduction of ray tracing the total simulation time in sweep simulations:that involve a large number of transmitters and receivers. Certain simulation modes of EM.Terrano are intended for the Polarimatrix solver only as will be described in the next section.

# Set the unit EM.Terrano provides a number of project scene and the frequency of operation. Note different simulation modes that [[EM.Cube]]'s default project unit is millimeter. When working with the [[Propagation Module]], pay attention to the project unit. Radio propagation problems usually require meter, mile involve single or kilometer as the project unit.# 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 properties.# Define the base sets (at least one for the transmitter and one for the receiver).# Define the transmitter and receiver(s) using the available base sets.# Run the SBR multiple simulation engine.# Visualize the coverage map and plot other data.runs:

You can access the {| class="wikitable"|-! scope="col"| Simulation Mode! scope="col"| Usage! scope="col"| Which Solver?! scope="col"| Frequency ! scope="col"| Restrictions|-| style="width:120px;" | [[Propagation Module#Running a Single-Frequency SBR Analysis | Single-Frequency Analysis]]'s run dialog by clicking | style="width:180px;" | Simulates the '''Run''' 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;" | [[File:run_iconParametric_Modeling_%26_Simulation_Modes_in_EM.pngCube#Running_Frequency_Sweep_Simulations_in_EM.Cube | Frequency Sweep]] button | style="width:180px;" | Varies the operating frequency of the '''Simulate Toolbar''' or by selecting '''Simulate &gtray tracer | style="width:150px; Run" | 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 using more project variables| style="width:150px;" | SBR| style="width:120px;" | Runs at the keyboard shortcut '''Ctrl+R'''. When you click the '''Run''' buttoncenter frequency fc| style="width:300px;" | Requires definition of sweep variables, a new window opens up that reports works only with SBR solver as the different stages of physical scene may change during the SBR 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 indicates requires an existing ray database|-| style="width:120px;" | [[#Rotational_Sweep | Rotational Sweep]]| style="width:180px;" | Rotates the progress radiation pattern of each stage. After the SBR 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 is successfully completed, run to model a message pops up and prompts mobile communication link| style="width:150px;" | Polarimatrix| style="width:120px;" | Runs at the completion of center frequency fc| style="width:300px;" | Requires the process.same number of transmitters and receivers, works only with Polarimatrix solver and requires an existing ray database|}

[[File:PROP12Click on each item in the above list to learn more about each simulation mode.png]]

Figure 1: [[Propagation Module]]You set the simulation mode in EM.Terrano's Simulation Run simulation run dialogusing 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.

[[When your propagation scene contains two or more transmitters, whether they all belong to the same transmitter set with the same radiation pattern or to different transmitter sets, EM.Cube]] requires a finite number of ray bounces for each original ray emanating from a transmitterTerrano assumes all to be coherent with respect to one another. This is very important in situations that may involve resonance effects where In other words, synchronous transmitters are always assumed. The rays get trapped among certain group of surfaces and may bounce back originating from all these transmitters are superposed coherently and forth indefinitelyvectorially at each receiver. This is set using In a transmitter sweep, on the box labeled &quot;'''Max No. Ray Bounces'''&quot;other hand, which has a default value of 10EM. Note that the maximum number of ray bounces directly affects the computation Terrano assumes only one transmitter broadcasting at a time as well as the size of output simulation data files. This can become critical for indoor propagation scenes, where most The result of the rays undergo sweep simulation is a large number of reflectionsreceived power coverage maps, each corresponding to a transmitter in the scene.

As rays travel in the scene and bounce from surfaces, they lose their power and their amplitudes diminish{{Note| EM. From a practical point of view, Terrano's transmitter sweep works only rays that have power above with the receiver sensitivity threshold can be effectively received. Therefore, all the rays whose power fall below a specified power threshold are discarded. The '''Ray Power Threshold''' is specified in dBm Polarimatrix Solver and has a default value of -100dBm. Keep in mind that the value of this threshold directly affects the accuracy of the simulation results as well as the size of requires an existing ray database previously generated using the output data fileChannel Analyzer.}}

[[File:PROP13You 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]]

Figure 1: [[Propagation Module]]{{Note| EM.Terrano's SBR Engine Settings dialogrotational sweep works only with the Polarimatrix Solver and requires an existing ray database previously generated using the Channel Analyzer.}}

=== The Coverage Map Mobile Sweep ===

If the associated radiator set is isotropicIn a mobile sweep, so will be the each transmitter setis paired with a receiver according to their indices in their parent sets. By defaultAt each simulation run, an isotropic transmitter has vertical polarization. You can use the '''Polarization''' radio button to select only one of (Tx, Rx) pair is considered to be active in the two options: '''Vertical''' or '''Horizontal'''scene. If As a result, the associated radiator set consists generated coverage map takes a different meaning implying the sequential movement of '''Short Dipole''' or '''User Defined''' radiators, it is indicated in the transmitter property dialogand receiver pair along their corresponding paths. In other words, the case set of a short dipole radiator, you can point transmitters and the set a value for of point receivers indeed represent the dipole current in Amperes. The radiation resistance locations of a short dipole single transmitter and a single receiver at different instants of length ''dl'' time. It is given by:obvious that the total number of transmitters and total number of receivers in the scene must be equal. Otherwise, EM.Terrano will prompt an error message.

:<math> R_r = 80\pi^2 \left[[EM.Cube]] provides a '''Mobile Path Wizard''' that facilitates the creation of a transmitter set or a receiver set along a specified path. This path can be an existing nodal curve ( \frac{dl}{\lambda_0} \rightpolyline or NURBS curve)^2 </math><!--or an existing line objects. You can also import a sptial Cartesian data file containing the coordinates of the base location points. For more information, refer to [[File:eqngr6Glossary_of_EM.pngCube%27s_Wizards#Mobile_Path_Wizard | Mobile Path Wizard]]-->.

:<math> P_{rad} = \frac{1}{2} R_r |I_0|^2 = 40\pi^2 |I_0|^2 \left( \frac{dl}{\lambda_0} \right)^2 </math><!--[[File:shortdipole.png]]-->= Investigating Propagation Effects Selectively One at a Time ===

For isotropic and user defined radiators you can set the '''Input Power''' and '''Phase''' of In a transmitter set in Watts and degreestypical SBR ray tracing simulation, respectivelyEM. This can be accessed from Terrano includes all the '''Transmitter Chain''' dialogpropagation effects such as direct (LOS) rays, which will be described in detail in ray reflection and transmission, and edge diffractions. At the next section. The radiation pattern end of the associated radiator set is normalized and used in conjunction with the input power value to create a weighted distribution of transmitted rays. In certain cases like hybrid simulationsSBR simulation, you may want to use can visualize the actual values of the far field to define the transmitter received power rather than a normalized radiation pattern. Note that the pattern (.RAD) file contains the value coverage map of total radiated power in its header. In this caseyour propagation scene, check which appears under the box labeled '''&quot;Calculate Power From Radiation Pattern&quot;'''. This is calculated directly from receiver set item in the complex &theta; and &phi; components of the far field data by integrating them over the entire space (4&pi; solid angle)navigation tree. Note that this option is available only when The figure below shows the radiator is received power coverage map 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 random city scene with a user defined associated radiator may represent a highly directional radiation pattern with vertically polarized half-wave dipole transmitter located 10m above the main beam pointing in a certain direction. You can additionally force ground and limit the '''Angular Extents''' of rays to a certain solid angle around the transmitter. This is especially useful and computationally efficient when the transmitter is on one side large grid of the scene, and all the scatterers and vertically polarized half-wave dipole receivers are on placed 1.5m above the other sideground. In this case, there is no need to generate rays in all directions. To limit The legend box shows the angular extents limits of rays, define the Start color map between -23dBm as the maximum and End values for both Theta -150dB (&theta;the default receiver sensitivity value) and Phi (&phi;) angles. The value of as the angular resolution of the rays can be changed from the Run Dialog as will be discussed laterminimum.

In a regular SBR simulation, you have a transmitter and one or more arrays of receivers in your scene<table><tr><td> [[Image:UrbanCanyon10. At the end of the simulation, you can visualize the png|thumb|left|640px|The received power 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 random city 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 with 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-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 dialogdipole transmitter.]] </td></tr></table>

[[File:prop_run11_tnSometime it is helpful to change the scale of the color map to better understand the dynamic range of the coverage map.png|400px]] [[File:prop_run12_tnIf you double-click on the legend or right-click on the coverage map's name in the navigation tree and select '''Properties''', the Plot Settings dialog opens up. Select the '''User-Defined''' item and set the lower and upper bounds of color map as you wish.png|400px]]

Figure<table><tr><td> [[Image: Received power UrbanCanyon15.png|thumb|left|480px|The plot settings dialog of the coverage map.]] </td></tr></table><table><tr><td> [[Image: (Left) confetti style, 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 (Right) cube style-20dBm.]] </td></tr></table>

You can change To better understand the settings of the coverage map by right clicking on its entry in the Navigation Tree and selecting '''Propertiesvarious propagation effects, EM...''' Terrano allows you to enable or by double-clicking on the legend boxdisable these effects selectively. In This is done from the Output Plot Ray Tracing Simulation Engine Settings dialog, you can choose from one of three Color Map options: '''Default''', '''Rainbow''' and '''Grayscale'''. The visualization plot uses default values for the color scale. In the section titled &quot;Limits&quot;, you can choose the radio button labeled '''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 using the buttons provided for this purposecheck boxes.

<table><tr><td> [[FileImage:prop_run4UrbanCanyon14.png|thumb|left|640px|EM.Terrano's simulation run dialog showing the check boxes for controlling various propagation effects.]]</td></tr></table>

=== The Ray Working with EM.Terrano's Simulation Data ===

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''Ray Tracing Solvers'.Output Simulation Data ===

[[File:prop_run5_tnBoth 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.png|800px]]

You can also view In wireless propagation modeling for communication system applications, the ray [[parameters]] by opening received power at the property dialog of a receiver set. By default, the first receiver of the set location is always selected. You can select any other receiver from more important than the drop-down list labeled '''Selected Receiver'''field distributions. If you click In order to compute the button labeled '''Show Ray Data'''received power, a new dialog opens up with a table that contains all the received rays at the selected receiver and their [[parameters]]you need three pieces of information:

* Delay is '''Total Transmitted Power (EIRP)''': This requires knowledge of the total time delay that a ray experiences travelling from baseband signal power, the transmitter chain parameters, the transmission characteristics of the transmission line connecting the transmitter circuit to the receiver after all the reflections, transmissions transmitting antenna and diffractions and is expressed in nanoseconds.* Ray Field is the received electric field at radiation characteristics of the receiver location due to a specific ray and is given in dBV/mtransmitting antenna.* Ray Power is the received power at the receiver due to a specific ray and '''Channel Path Loss''': This is given in dBmcomputed through SBR simulation.* Angles '''Receiver Properties''': This includes the radiation characteristics of Arrival are the &theta; and &phi; angles receiving antenna, the transmission characteristics of the incoming ray at transmission line connecting the local spherical coordinate system of receiving antenna to the receiver circuit and the receiverchain parameters.

The Ray Data Dialog also shows In a simple link scenario, 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 P_r 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 dBm is highlighted in the Project Workspace and all found from the other rays become thin (faded).following equation:

[[File:prop_run6_tnwhere 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.png|800px]]

FigureIf you specify the noise-related parameters of your receiver set, the signal-to-noise ratios (SNR) is calculated at each receiver location: Analyzing SNR = P_r - P_n, where P_n is the noise power level in dB. When planning, designing and deploying a selected ray from communication system between points A and B, the ray data 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.

Besides visualizing the coverage map and received rays in the <table><tr><td>[[EMImage:AnnArbor Scene1.Cubepng|EMthumb|left|640px|The downtown Ann Arbor propagation scene.CUBE]]'s </td></tr><tr><td>[[Propagation Module]], you can also plot the '''Path Loss''' of all the receivers belonging to a receiver set as well as the '''Power Delay Profile''' of individual receiversImage:AnnArbor Scene2. To plot these data, go the '''Observables''' section png|thumb|left|640px|The electric field distribution map of the Navigation Tree Ann Arbor scene with vertical dipole transmitter and right click on the '''Receivers''' itemreceivers. From the context menu, select '''Plot Path Loss''' or '''Plot Power Delay Profile''', respectively]]</td></tr><tr><td>[[Image:AnnArbor Scene3. png|thumb|left|640px|The path loss data between received power coverage map of the active Ann Arbor scene with vertical dipole transmitter and all the receivers belonging to a receiver set are plotted on a Cartesian graph. ]]</td></tr><tr><td>[[Image:AnnArbor Scene4.png|thumb|left| 640px |The horizontal axis connectivity map of this graph represents the index of Ann Arbor scene with SNR_min = 3dB with the receiverbasic color map option. Power Delay Profile is a bar chart that plots the power of individual rays received by the currently selected receiver versus their time delay]]</td></tr><tr><td>[[Image:AnnArbor Scene5. If there is a line png|thumb|left| 640px |The connectivity map of sight (LOS) between a transmitter and receiver, the LOS ray will have the smallest delay and therefore will appear first in the bar chart. Sometimes you may have several rays arriving at a receiver at the same time, i.e. all Ann Arbor scene with the same delay, but SNR_min = 20dB with different power level. These will appear as stacked bars in the chartbasic color map option.]]</td></tr></table>

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

At You can also view the end ray parameters by opening the property dialog of an SBR simulationa receiver set. By default, the results are written into a main output data file with the reserved name first receiver of SBR_Resultsthe set is always selected.RTOUTYou can select any other receiver from the drop-down list labeled '''Selected Receiver'''. This file has If you click the button labeled '''Show Ray Data''', a new dialog opens up with a table that contains all the received rays at the following formatselected receiver and their parameters:

NEW LINE<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 NumberIndex* 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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