Changes

[[Image:Splash-prop.jpg|right|720px]]<strong><font color="#4e1985" size="4">True 3D, Coherent, Polarimetric Ray Tracer That Simulates Very Large Urban Scenes In Just Few Minutes!</font></strong><table><tr><td>[[image:Cube-icon.png | link=Getting_Started_with_EM.Cube]] [[image:cad-ico.png | link=Building_Geometrical_Constructions_in_CubeCAD]] [[image:fdtd-ico.png | link= An EM.Terrano Primer Tempo]] [[image:static-ico.png | link=EM.Ferma]] [[image:planar-ico.png | link=EM.Picasso]] [[image:metal-ico.png | link=EM.Libera]] [[image:po-ico.png | link=EM.Illumina]]</td><tr></table>[[Image:Tutorial_icon.png|30px]] '''[[EM.Cube#EM.Terrano_Documentation | EM.Terrano Tutorial Gateway]]'''

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

Every wireless communication system involves a transmitter that transmits some sort of signal (voice, video, data, etc===EM.), a receiver that receives and detects the transmitted signal, and a channel Terrano in which the signal is transmitted into the air and travels from the location of the transmitter to the location of the receiver. The channel is the physical medium in which the electromagnetic waves propagate. The successful design of a communication system depends on an accurate link budget analysis that determines whether the receiver receives adequate signal power to detect it against the background noise. The simplest channel is the free space. Real communication channels, however, are more complicated and involve a large number of wave scatterers. For example, in an urban environment, the obstructing buildings, vehicles and vegetation reflect, diffract or attenuate the propagating radio waves. As a result, the receiver receives a distorted signal that contains several components with different power levels and different time delays arriving from different angles.Nutshell ===

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

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

EM[[Image:Info_icon.Terrano is a physics-based, site-specific, wave propagation modeling tool that enables engineers png|30px]] Click here to quickly determine how radio waves propagate in urban, natural or mixed environments. EM.Terrano's simulation engine is equipped with a fully polarimetric, coherent ray tracing solver based on the Shooting-and-Bouncing-Rays (SBR) method, which utilizes geometrical optics (GO) in combination with uniform theory of diffraction (UTD) models of building edges. EM.Terrano lets you analyze and resolve all the rays transmitted from one ore learn more signal sources, which propagate in a real physical site made up of buildings, terrain and other obstructing structures. EM.Terrano finds all about the rays received by a receiver at a particular location in the physical site and computes their power levels, time delays, angles '''[[Basic Principles of arrival, etc. Using EM.Terrano you can examine connectivity of a communication link between any two points in a real specific propagation siteSBR Ray Tracing | Basic SBR Theory]]'''.

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

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

[[Image:MOREEM.png|40px]] Click here to learn more about Terrano is the theory ray tracing '''Propagation Module''' of a '''[[Free-Space Propagation ChannelEM.Cube]]''', a comprehensive, integrated, modular electromagnetic modeling environment. EM.Terrano shares the visual interface, 3D parametric CAD modeler, data visualization tools, and many more utilities and features collectively known as [[Building_Geometrical_Constructions_in_CubeCAD | CubeCAD]] with all of [[EM.Cube]]'s other computational modules.

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

Link budget analysis for a multipath channel is a challenging task due to the large size of the computational domains involved. Typical propagation scenes usually involve length scales on the order of thousands of wavelengths. To calculate the path loss between the transmitter and receiver, one must solve [[Maxwell's EquationsImage:Info_icon.png|Maxwell's equations30px]] in an extremely large space. Full-wave numerical techniques like the Finite Difference Time Domain (FDTD) method, which require a fine discretization of the computational domain, are therefore impractical for solving large-scale propagation problems. The practical solution is Click here to use asymptotic techniques such as SBR, which utilize analytical techniques over large distances rather than a brute force discretization of the entire computational domainlearn more about '''[[Getting_Started_with_EM. Such asymptotic techniques, of course, have to compromise modeling accuracy for computational efficiencyCube | EM.Cube Modeling Environment]]'''.

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

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

When EM.Terrano performs fully polarimetric and coherent SBR simulations with arbitrary transmitter antenna patterns. Its SBR simulation engine is a true asymptotic &quot;field&quot; solver. The amplitudes and phases of all the three vectorial field components are computed, analyzed and preserved throughout the entire ray hits an obstructing surfacetracing process from the source location to the field observation points. You can visualize the magnitude and phase of all six electric and magnetic field components at any point in the computational domain. In most scenes, the buildings and the ground or terrain can be assumed to be made of homogeneous materials. These are represented by their electrical properties such as permittivity &epsilon;_r and electric conductivity &sigma;. More complex scenes may involve a multilayer ground or multilayer building walls. In such cases, one can no longer use the simple reflection or more transmission coefficient formulas for homogeneous medium interfaces. EM.Terrano calculates the reflection and transmission coefficients of multilayer structures as functions of incident angle, frequency and polarization and uses them at the following phenomena may happen:respective specular points.

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

<table><tr><td> [[Image:MOREMultipath_Rays.png|40px]] Click here to learn more about thumb|left|500px|A multipath urban propagation scene showing all the theory of '''[[SBR Methodrays collected by a receiver.]]'''.</td></tr></table>

=== Pros and Cons of EM.Terrano's SBR Solver =Features at a Glance ==

EM.Terrano performs fully polarimetric <ul> <li> Buildings/blocks with arbitrary geometries and coherent SBR simulations material properties</li> <li> Buildings/blocks with impenetrable surfaces or penetrable surfaces using thin wall approximation</li> <li> Multilayer walls for indoor propagation scenes</li> <li> Penetrable volume blocks with arbitrary transmitter antenna patterns. Its SBR simulation engine is a true asymptotic &quot;field&quot; solver. The amplitudes geometries and phases material properties</li> <li> Import of all the three vectorial field components are computedshapefiles and STEP, analyzed IGES and preserved throughout the entire ray tracing process from the source location to the field observation points. You can visualize the magnitude STL CAD model files for scene construction</li> <li> Terrain surfaces with arbitrary geometries and phase of all six electric material properties and magnetic field components at any point in the computational domain. In most scenesrandom rough surface profiles</li> <li> Import of digital elevation map (DEM) terrain models</li> <li> Python-based random city wizard with randomized building locations, the extents and orientations</li> <li> Python-based wizards for generation of parameterized multi-story office buildings and the ground or several terrain can be assumed to be made of homogeneous materials. These are represented by their electrical properties such as permittivity &epsilon;scene types<sub/li>r </subli> Standard half-wave dipole transmitters and electric conductivity &sigma;. More complex scenes may involve a multilayer ground or multilayer building walls. In such cases, one can no longer use receivers oriented along the simple reflection principal axes</li> <li> Short Hertzian dipole sources with arbitrary orientation</li> <li> Isotropic receivers or transmission coefficient formulas receiver grids for homogeneous medium interfaces. EM.Terrano calculates the reflection and transmission coefficients 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 multilayer structures as functions imported antenna patterns</li> <li> Interchangeable radiator-based definition of incident angle, frequency transmitters and polarization and uses them at the respective specular points. receivers (networks of transceivers)</li></ul>

[[Image:PROP14<ul> <li> Fully 3D polarimetric and coherent Shoot-and-Bounce-Rays (1SBR).png|thumb|250px|The Navigation Tree simulation engine</li> <li> GTD/UTD diffraction models for diffraction from building edges and terrain</li> <li> Triangular surface mesh generator for discretization of EM.Terrano]]arbitrary block geometries</li>== Building <li> Super-fast geometrical/optical ray tracing using advanced k-d tree algorithms</li> <li> Intelligent ray tracing with user defined angular extents and resolution</li> <li> Ray reflection, edge diffraction and ray transmission through multilayer walls and material volumes</li> <li> Communication link analysis for superheterodyne transmitters and receivers</li> <li> 17 digital modulation waveforms for the calculation of E_b/N₀ and Bit error rate (BER)</li> <li> Incredibly fast frequency sweeps of the entire propagation scene in a Propagation Scene ==single SBR simulation run</li> <li> Parametric sweeps of scene elements like building properties, or radiator heights and rotation angles</li> <li> Statistical analysis of the propagation scene</li> <li> Polarimetric channel characterization for MIMO analysis</li> <li> "Almost real-time" Polarimatrix solver using an 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 mobile path using the Polarimatrix solver</li></ul>

An outdoor propagation scene may involve several buildings modeled by impenetrable surfaces and an underlying flat ground or irregular terrain surface. An indoor propagation scene may involve several walls modeled by thin penetrable surfaces<ul> <li> Standard output parameters for received power, a ceiling path loss, SNR, E_b/N₀ and a floor arranged according to a certain building layout. You can also build mixed scenes involving both impenetrable and penetrable blocks. Your sources and observables can be placed anywhere BER at each individual receiver</li> <li> Graphical visualization of propagating rays in the scene. Your transmitters </li> <li> Received power coverage maps</li> <li> Link connectivity maps (based on minimum required SNR and receivers can be placed outdoors or indoors. A complete list BER)</li> <li> Color-coded intensity plots of the various elements polarimetric electric field distributions</li> <li> Incoming ray data analysis at each receiver including delay, angles of arrival and departure</li> <li> Cartesian plots of path loss along defined paths</li> <li> Power delay profile of a propagation scene is given in the '''Physical Structure''' section selected receiver</li> <li> Polar stem charts of EM.Terrano's Navigation Tree as follows:angles of arrival and departure of the selected receiver</li></ul>

* '''[[Block_Types#Impenetrable_Surfaces_for_Outdoor_Scenes|Impenetrable Surfaces]]''': feature reflection and diffraction of impinging rays. Rays hit the facets of this type of blocks and bounce back, but they do not penetrate the object. It is assumed that the interior of such blocks or buildings are highly absorptive.* '''[[Block_Types#Penetrable_Volumes|Penetrable Volumes]]''': feature reflection, transmission and diffraction of impinging rays. These blocks are used to model propagation inside general material media or fog, rain and vegetation.* '''[[Block_Types#Penetrable_Surfaces_for_Indoor_Scenes|Penetrable Surfaces]]''': feature reflection, transmission and diffraction of impinging rays. These blocks represent thin surfaces that are used to model the exterior and interior walls of buildings. Rays reflect off the surface of penetrable surfaces and diffract off their edges. They also penetrate the thin surface and continue their path in the free space on the other side of the wall.* '''[[Block_Types#Terrain_Surfaces_vs._Global_Ground|Terrain Surfaces]]''': feature reflection and optional diffraction of impinging rays. These blocks are used to provide one or more impenetrable, ground surfaces for the propagation scene. Rays simply bounce off terrain objects. * '''[[#Defining_Base_Point_Sets|Base Points]]''': are used to define transmitter and receiver locations == Building a Propagation Scene in the sceneEM.Terrano ==

=== Adding The Various Elements of a New Propagation Scene Element ===

In A typical propagation scene in EM.Terranoconsists of several elements. At a minimum, you need a transmitter (Tx) at some location to launch rays into the scene elements like buildings, terrain objects and based points are grouped a receiver (Rx) at another location to receive and collect the incoming rays. A transmitter and a receiver together based on their typemake the simplest propagation scene, representing a free-space line-of-sight (LOS) channel. All In EM.Terrano, a transmitter represents a point source, while a receiver represents a point observable. Both a transmitter and a receiver are associated with point objects, which are one of the many types of geometric objects listed under a particular impenetrable surface group you can draw in the navigation tree share the same material properties and color and textureproject workspace. To define Your scene might involve more than one transmitter and possibly a new block group, follow these steps:large grid of receivers.

# Right click on the name A more complicated propagation scene usually contains several buildings, walls, or other kinds of the element type scatterers and wave obstructing objects. You model all of these elements by drawing geometric objects in the navigation tree and select '''Insert New Blockproject workspace or by importing external CAD models.EM.Terrano does not organize the geometric objects of your project workspace by their material composition.''' A dialog for setting up Rather, it groups the block properties opens up with geometric objects into blocks based on a default color, texture and predefined material common type (except for the case of a base point). # Specify a name for the block group and select a color or texture.# The electromagnetic model that determines ray-block interactions is specified under '''Interface Type''' or '''Surface Type'''. In most applications, you will use a standard materials interaction with known electrical properties, i.e. '''Permittivity''' (&epsilon;_r) and '''Electric Conductivity''' (&sigma;)incident rays. EM.Terrano does not handle magnetic materials.# Click offer the '''OK''' button following types of the dialog to accept the changes and close it.object blocks:

Once a new block node has been created on the navigation tree{| class="wikitable"|-! scope="col"| Icon! scope="col"| Block/Group Type ! scope="col"| Ray Interaction Type! scope="col"| Object Types Allowed! scope="col"| Notes|-| style="width:30px;" | [[File:impenet_group_icon.png]]| style="width:150px;" | [[Glossary of EM.Cube's Materials, it becomes the 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="Activewidth:300px;" | Basic building group for outdoor scenes|-| style="width:30px;" | [[File:penet_surf_group_icon.png]]| style="width:150px;" | [[Glossary of the project workspaceEM.Cube's Materials, Sources, Devices & Other Physical Object Types#Penetrable Surface | Penetrable Surface]]| style="width:200px;" | Ray reflection, ray diffraction, which is always displayed ray transmission in bold letters. Then you can start drawing new free space| style="width:250px;" | All solid & surface geometric objects under that node, no curve objects| style="width:300px;" | Behaves similar to impenetrable surface and uses thin wall approximation for generating transmitted rays, used to model hollow buildings with ray penetration, entry and exit |-| style="width:30px;" | [[File:terrain_group_icon. Any block group png]]| style="width:150px;" | [[Glossary of EM.Cube's Materials, Sources, Devices & Other Physical Object Types#Terrain Surface | Terrain Surface]]| style="width:200px;" | Ray reflection, ray diffraction| style="width:250px;" | All surface geometric objects, no solid or curve objects | style="width:300px;" | Behaves exactly like impenetrable surface but can be made active by right clicking on its name in change the navigation tree and selecting elevation of all the buildings and transmitters and receivers located above it|-| style="width:30px;" | [[File:penet_vol_group_icon.png]]| style="width:150px;" | [[Glossary of EM.Cube's Materials, Sources, Devices & Other Physical Object Types#Penetrable Volume | Penetrable Volume]]| style="width:200px;" | Ray reflection, ray diffraction, ray transmission and ray attenuation inside homogeneous material media| style="width:250px;" | All solid geometric objects, no surface or curve objects| style="width:300px;" | Used to model wave propagation inside a volumetric material block, also used for 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''Activate''' item s Materials, Sources, Devices & Other Physical Object Types#Base Location Set | Base Location Set]]| style="width:200px;" | Either ray generation or ray reception| style="width:250px;" | Only point objects| style="width:300px;" | Required for the definition of transmitters and receivers|-| style="width:30px;" | [[File:scatterer_group_icon.png]]| style="width:150px;" | [[Glossary of EM.Cube's Materials, Sources, Devices & Other Physical Object Types#Point Scatterer Set | Point Scatterer Set]]| style="width:200px;" | Ray reception and ray scattering| style="width:250px;" | Only point, box and sphere objects| style="width:300px;" | Required for the contextual menudefinition of point scatterers as targets in a radar simulation |-| style="width:30px;" | [[File:Virt_group_icon. png]]| style="width:150px;" | [[Glossary of EM.Cube's Materials, Sources, Devices & Other Physical Object Types#Virtual_Object_Group | Virtual Object]]| style="width:200px;" | No ray interaction| style="width:250px;" | All types of objects| style="width:300px;" | Used for representing non-physical items |}

It is recommended that you first create block groups, and then draw new objects under Click on each type to learn more about it in the active block group. However, if you start a new [[Glossary of EM.Terrano project from scratchCube's Materials, and start drawing a new object without having previously defined any block groupsSources, a new default impenetrable surface group is created and added to the navigation tree to hold your new CAD objectDevices & Other Physical Object Types]].

You can always change Impenetrable surfaces, penetrable surfaces, terrain surfaces and penetrable volumes represent all the properties objects that obstruct the propagation of electromagnetic waves (rays) in the free space. What differentiates them is the types of physical phenomena that are used to model their interaction with the impinging rays. EM.Terrano discretizes geometric objects into a block group later by accessing its property dialog from number of flat facets. The field intensity, phase and power of the contextual menureflected and transmitted rays depend on the material properties of the obstructing facet. You The specular surface of a facet can also delete be modeled locally as a block group with its simple homogeneous dielectric half-space or as a multilayer medium. In that respect, all the obstructing objects at any timesuch as buildings, walls, terrain, etc.behave in a similar way:

[[Image:PROP15* They terminate an impinging ray and replace it with one or more new rays.png|thumb|400px|EM.Terrano's Domain Settings dialog.]][[Image:PROP4* They represent a specular interface between two media of different material compositions for calculating the reflection, transmission or diffraction coefficients.png|thumb|400px|EM.Terrano's Global Ground Settings dialog.]]=== Computational Domain &amp; Global Ground ===

The SBR simulation engine requires a finite computational domainAn outdoor propagation scene typically involves several buildings modeled by impenetrable surfaces. All the stray rays that Rays hit the boundaries facets of this finite domain are terminated during impenetrable buildings and bounce back, but they do not penetrate the simulation processobject. Such rays exit the computational domain and travel to It is assumed that the infinity, with no chance interior of ever reaching any receiver in the scenesuch buildings are highly dissipative due to wave absorption or diffusion. When you define a An indoor propagation scene with various elements like buildings, typically involves several walls, terrain, etc., a dynamic domain is automatically established ceiling and displayed as a green wireframe box that surrounds floor arranged according to a certain building layout. Penetrable surfaces are used to model the entire sceneexterior and interior walls of buildings. Every time you create a new object, Rays reflect off these surfaces and diffract off their edges. They also penetrate the domain is automatically adjusted thin surface and extended continue their path in the free space on the other side of the wall. Terrain surfaces with irregular shapes or possibly random rough surfaces are used as an alternative to enclose all the objects in flat global ground. You can also build mixed scenes involving both impenetrable and penetrable blocks or irregular terrain. In the context of a propagation scene, penetrable volumes are often used to model block of rain, fog or vegetation. Base location sets are used to geometrically represent point transmitters and point receivers in the project workspace.

The size of the Ray domain Sometimes it is specified helpful to draw graphical objects as visual clues 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 unitsworkspace. You can change them arbitrarilyThese non-physical objects must belong to a virtual object group. After changing these valuesVirtual objects are not discretized by EM.Terrano's mesh generator, use the '''Apply''' button to make the changes effective while the dialog is still open.You can change the size and color of they are not passed onto the domain box through the Ray Domain Settings Dialog, which can be accessed in one input data files of the following three ways:SBR simulation engine.

# Click the '''Domain''' <table><tr><td> [[FileImage:image025PROP MAN2.jpg]] button of the Simulation Toolbarpng|thumb|left|720px|An urban propagation scene generated by EM.# Select the Terrano'''Simulate''' &gt; '''Computational Domain''' &gt; '''Settingss "Random City" and "Basic Link" wizards...''' item It consists of the Simulate Menu.# Right click on the '''Ray Domain''' item 25 cubic brick buildings, one transmitter and a large two-dimensional array of the Navigation Tree and select '''Domain Settingsreceivers...''']]# Use the keyboard shortcut '''Ctrl + A'''.</td></tr></table>

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 a translucent green plane at z = 0 extending downward. The color of Organizing 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 Propagation Scene by Block Groups == 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.'''

=== BuildingsIn EM.Terrano, Terrain & Obstructing Blocks ===all the geometric objects associated with the various scene elements like buildings, terrain surfaces and base location points are grouped together as blocks based on their common type. All the objects listed under a particular group in the navigation tree share the same color, texture and material properties. Once a new block group has been created in the navigation tree, it becomes the "Active" group of the project workspace, which is always displayed in bold letters. You can draw new objects under the active node. Any block group can be made active by right-clicking on its name in the navigation tree and selecting the '''Activate''' item of the contextual menu.

Impenetrable, penetrable and terrain surfaces and penetrable volumes represent buildings, blocks or objects that obstruct the propagation of electromagnetic waves (rays) in the free space<table><tr><td> [[Image:PROP MAN1. What differentiates them is the types of physical phenomena that are used to model their interaction with the impinging rayspng|thumb|left|480px|EM. The field intensity, phase and power of the reflected and transmitted rays depend on the material properties of the obstructing surfaceTerrano's navigation tree. The specular surface can be modeled as a simple homogeneous dielectric half-space or as a multilayer structure. In that respect, the buildings, walls, terrain or even the global ground all behave in a similar way:]]</td></tr></table>

* They terminate an impinging ray It is recommended that you first create block groups, and replace it with one or more then draw new raysobjects under the active block group.* They represent However, if you start a specular interface between two media of different material compositions for calculating the reflectionnew EM.Terrano project from scratch, transmission and possibly diffraction coefficientsstart 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.

[[EM{{Note|You can only import external CAD models (STEP, IGES, STL, DEM, etc.Terrano]] has generalized ) only to the concept of '''Block''' as any object that obstructs and affects radio wave propagationCubeCAD module. The following table summarized You can then transfer the [[Block Types|block types]]: imported objects from CubeCAD to EM.Terrano.}}

{| class="wikitable"|-! scope="col"| = Moving Objects Among Different Block Type! scopeGroups =="col"|Physical Effects! scope="col"|Legitimate Object Types|-| Impenetrable Surface| Reflection, Diffraction| All solid &amp; surface CAD objects|-| Penetrable Volume| Reflection, Diffraction, Material Medium Transmission| All solid CAD objects|-| Penetrable Surface| Reflection, Diffraction, Thin-Wall Transmission| All solid &amp; surface CAD objects|-| Terrain Surface| Reflection| Only tessellated objects either imported externally or created [[using Terrain Generator]]|}

You can move any geometric object or a selection of objects from one block group to another. You can also transfer objects among [[Image:MOREEM.png|40pxCube]] Click here 's different modules. For example, you often need to learn more about move imported CAD models of terrain or buildings from CubeCAD to EM.Terrano. To transfer objects, first select them in the project workspace or select their names in the navigation tree. Then right-click on them and select <b>Move To &rarr; Module Name &rarr; Object Group</b> from the contextual menu. For example, if you want to move a selected object to a block group called "Terrain_1" in EM.Terrano, then you have to select the menu item '''[[Block Types]]Move To &rarr; EM.Terrano &rarr; Terrain_1'''as shown in the figure below. Note that you can transfer several objects altogether using the keyboards's {{key|Ctrl}} or {{key|Shift}} keys to make multiple selections.

<table><tr><td> [[Image:prop_manual-12_tnPROP MAN3.png|thumb|600pxleft|An 720px|Moving the terrain model of Mount Whitney originally imported from an external digital elevation map (DEM) file to EM.Terrano.]]</td></tr><tr><td>[[Image:PROP MAN4.png|thumb|left|720px|The imported terrain modelof Mount Whitney shown in EM.Terrano's project workspace under a terrain group called "Terrain_1".]]</td></tr></table>

=== Importing &amp; Exporting Adjustment of Block Elevation on Underlying Terrain Models Surfaces ===

You can import two types of terrain in In EM.Terrano, buildings and all other geometric objects are initially drawn on the XY plane. The first type is &quot;'''.TRN&quot;''' terrain fileIn other words, which is EMthe Z-coordinates of the local coordinate system (LCS) of all blocks are set to zero until you change them.Terrano's native terrain format. It Since the global ground is located a basic digital elevation map with a very simple ASCII data file formatz = 0, your buildings are seated on the ground. The resolution When your propagation scene has an irregular terrain, you would want to place your buildings on the surface of the terrain map in the X and Y directions is specified in meters not buried under it. This can be done automatically as STEPS. The (x, y, z) coordinates part of the terrain points are then listed one point per line. The other type definition of terrain format supported by [[EM.Cube]] is the standard '''7block group.5min DEM''' file format with Open the property dialog of a block group and check the box labeled '''.DEMAdjust Block to Terrain Elevation''' file extension. All the objects belonging to that block are automatically elevated in the Z direction such that their bases sit on the surface of their underlying terrain. In effect, the LCS of each of these individual objects is translated along the global Z-axis by the amount of the Z-elevation of the terrain object at the location of the LCS.

To import an external terrain model, first you {{Note| You have to create a terrain group node in make sure that the Navigation Tree. Right click on the name resolution of the your terrain group in the Navigation Tree , its variation scale and select either '''Import Terrainbuilding dimensions are all comparable...''' or '''Import DEM File...''' A standard [[Windows]] '''Open Dialog''' opens upOtherwise, with on a rapidly varying high-resolution terrain, you will have buildings whose bottoms touch the file type set to .TRN or .DEM extensions, respectively. You can browse your folders terrain only at a few points and find parts of them hang in the right terrain model file to importair.}}

You can also export all the terrain objects in the project workspace as a terrain file with a '''<table><tr><td> [[Image:PROP MAN5.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 png|thumb|left|480px|The property dialog of impenetrable surface showing the terrain, select '''File''' &gt; '''Exportelevation adjustment box checked...''' from EM.Terrano'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 the terrain data.</td></tr></table>

You can move one or more selected objects at a time among different block groups. The objects can be selected either in the project workspace, or their names can be selected from the navigation tree. Right click on the highlighted selection and select '''Move To > Propagation >''' from the contextual menu. This opens up another sub-menu with a list of all the available block groups already defined in your == EM.Terrano project. Select the desired block node, and all the selected objects will move to that block group. In the case of a multiple selection from the navigation tree using the keyboard's '''Shift Key''' or '''Ctrl Key''', make sure that you continue to hold the keyboard's '''Shift Key''' or '''Ctrl Key''' down while selecting the destination block group's name from the contextual menu.Ray Domain & Global Environment ==

In a similar way, you can move one or more objects from an EM.Terrano block group to one of [[EM.Cube]]'s other modules. In this case, the sub-[[menus]] of the '''Move To >''' item of the contextual menu will indicate all the [[EM.Cube]] modules that have valid groups for transfer of the selected objects. === Why Do You can also move one or more objects from [[EM.Cube]]'s other modules to Need a block group in EM.Terrano. Finite Computational Domain? ===

{{Note|Except The SBR simulation engine requires a finite computational domain for external terrain modelsray termination. All the stray rays that emanate from a source inside this finite domain and hit its boundaries are terminated during the simulation process. Such rays exit the computational domain and travel to the infinity, with no chance of ever reaching any receiver in the scene. When you can import other external objects (STEPdefine a propagation scene with various elements like buildings, IGESwalls, STLterrain, etc.) only to '''[[CubeCAD]]''', a dynamic domain is automatically established and displayed as a green wireframe box that surrounds the entire scene. You need Every time you create a new object, the domain box is automatically adjusted and extended to move enclose all the imported objects form [[CubeCAD]] to EM.Terrano as described abovein the scene.}}

Like every other electromagnetic solver* Open the Ray Domain Settings Dialog by clicking the '''Domain''' [[File:image025.jpg]] button of the '''Simulate Toolbar''', EMor by selecting '''Menu > Simulate > Computational Domain > Settings...Terrano's SBR ray tracer requires a source for excitation and one '', or more observables for generation by right-clicking on the '''Ray Domain''' item of simulation datathe navigation tree and selecting '''Domain Settings. EM.Terrano offers several types .''' from the contextual menu, or simply using the keyboard shortcut {{key|Ctrl+A}}.* The size of sources the Ray domain is specified in terms of six '''Offset''' parameters along the ±X, ±Y and observables for a SBR simulation±Z directions. The default value of all these six offset parameters is 10 project units. Change these values as you like.* You can mix and match different source types and observable types depending on also change the requirements color of your modeling problemthe 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. There are two types of sources:

* [[#Defining Transmitter Sets|Transmitter]]<table><tr><td> * [[Asymptotic_Field_SolverImage:PROP15.png|Hertzian Dipolethumb|left|480px|EM.Terrano's domain settings dialog.]]</td></tr></table>

=== Using Alternatively, you can use EM.Terrano as 's '''Empirical Soil Model''' to define the material properties of the global ground. This model requires a Field Solver ===number of parameters: Temperature in &deg;C, and Volumetric Water Content, Sand Content and Clay Content all as percentage.

The simplest SBR simulation can be performed using {{Note|To model a short dipole source with a specified field sensor plane. As an asymptotic EM solverfree-space propagation scene, you have to disable EM.Terrano then computes the electric and magnetic fields radiated by your dipole source in the presence of your multipath propagation environment. EM.Terrano's short dipole source and field sensor observable are very similar to those of [[EM.Cube]]'s other computational modules. You can also compute the far field radiation patterns of a dipole in the presence of surrounding scatterers or compute the Huygens surface data for use in [[EM.Cube]]'s other modulesdefault global ground.}}

<table><tr><td> [[Image:MOREGlobal environ.png|40px]] Click here to learn more about using thumb|left|720px|EM.Terrano as an '''[[Asymptotic Field Solvers Global Environment Settings dialog.]]'''.</td></tr></table>

=== Defining Base Point Sets =Transmitters &amp; Point Receivers for Your Propagation Scene ==

[[File:PROP1.png|thumb|300px|[[Propagation Module]]'s Base Set dialog]]=== The Nature of Transmitters and receivers are more complicated source and observable types that can be used to model more realistic communication links. A conventional urban propagation scene can be set up using a transmitter and an array of receivers. In order to tie up transmitters and receivers with CAD objects in the project workspace, [[EM.Terrano]] uses point objects to define transmitters and receivers. These point objects represent the base of the location of transmitters and receivers in the computational domain. Hence, they are grouped together as &quot;Base Sets&quot;. You can easily interchange the role of transmitters and receivers in a scene by switching their associated bases. The usefulness of concept of base sets will become apparent later when you place transmitters or receivers on an irregular terrain and adjust their elevation. Receivers ===

To create a new base setIn EM.Terrano, right click on transmitters and receivers are indeed point radiators used for transmitting and receiving signals at different locations of the '''Base Sets''' item propagation scene. From a geometric point of Navigation Tree view, both transmitters and select '''Insert Base Setreceivers 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 [[EM.Cube]]''' s 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 generate electromagnetic waves that propagate in the physical scene. A dialog for setting up 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 Base Set properties opens up"Observables" section.

# Enter a name EM.Terrano provides three radiator types for the base set and change the default blue color if you wish. It is useful to differentiate the base point transmitter sets associated with transmitters and receivers by their color.# Click the '''OK''' button to close the Base Set Dialog.:

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#Half-coordinate wave dipole oriented along one of your radiatorthe three principal axes#Two collocated, otherwiseorthogonally polarized, 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 isotropic radiators #User defined (parallel to the XY planearbitrary).antenna with imported far-field radiation pattern

A transmitter is a point #Half-wave dipole oriented along one of the three principal axes#Polarization-matched isotropic radiator with a fully #User defined polarimetric radiation pattern over the entire 3D space in the spherical coordinate system. 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 (arbitrary) antenna with a &quot;'''.RAD'''&quot; file extension. It contains columns of spherical &phi; and &theta; angles as well as the real and imaginary parts of the complex-valued imported far 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. radiation pattern

To define a transmitter source in EM.Terrano, first you need to have at least one base point in your project workspace. In the &quot;Custom Pattern [[Parameters]]&quot;, click the '''Import Pattern''' button to set the path for the radiation data file. This opens up the standard [[Windows]] Open dialog, with the The default file type or extension set to &quot;.RAD&quot;. Browse your folders to find the right data file. A radiation pattern file usually contains the value of &quot;Total Radiated Power&quot; in its file header. This is used by default for power calculations in the SBR simulation. However, you can check the box labeled &quot;'''Custom Power'''&quot; and enter a value for the transmitter power in Watts. [[EM.Cube]] can also rotate the imported radiation pattern arbitrarily. In this case, you need to specify the '''Rotation''' angles in degrees about the X-, Y- and receiver radiator types are both vertical (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 Zdirected) half-axiswave dipoles.

[[FileThere are three different ways to define a transmitter set or a receiver set:PROP19(1).png]] [[File:PROP20(1).png]]

[[Propagation Module]]'s Transmitter dialog *By defining point objects or point arrays under physical base location sets in the navigation tree and then associating them with a user defined radiator selected.transmitter or receiver set*Using Python commands emag_tx, emag_rx, emag_tx_array, emag_rx_array, emag_tx_line and emag_rx_line*Using the "Basic Link" wizard

=== Defining Receiver Sets a Point Transmitter Set in the Formal Way ===

Receivers Transmitters act as observables sources in a propagation scene. The objective of A transmitter is a SBR simulation is to calculate point radiator with a fully polarimetric radiation pattern defined over the far-zone electric fields and entire 3D space in the total received power at the location of a receiverstandard spherical coordinate system. In that sense, receivers indeed act as field observation pointsEM. You need to define at least one receiver in the scene before Terrano gives you can run a SBR simulation. You define three options for the receivers of your scene by associating them radiator associated 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. point transmitter:

[[File:PROP21By default, EM.Terrano assumes that your transmitter is a vertically polarized (1Z-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.png]] [[File:PROP22The second choice of two orthogonally polarized isotropic radiators is an abstract source that is used for polarimetric channel characterization as will be discussed later.png]]

You can override the default radiator option and select any other kind of antenna with a more complicated radiation pattern. For this purpose, you have to import a radiation pattern data file to EM.Terrano. You can model any radiating structure using [[Propagation ModuleEM.Cube]]'s Receiver 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.

=== Adjustment of Tx/Rx Elevation above {{Note|By default, EM.Terrano assumes a Terrain Surface ===vertical half-wave dipole radiator for your point transmitter set.}}

A transmitter set always needs to be associated with an existing base location set with one or more point objects in the project workspace. Therefore, you cannot define a transmitter for your scene before drawing a point object under a base location set.  [[Image:prop_txrx1_tnInfo_icon.png|40px]] Click here to learn how to define a '''[[Glossary_of_EM.Cube%27s_Materials,_Sources,_Devices_%26_Other_Physical_Object_Types#Point_Transmitter_Set | Point Transmitter Set]]'''. <table><tr><td> [[Image:Terrano L1 Fig11.png|thumb|400pxleft|480px|The point transmitter set definition dialog.]] </td></tr></table> Once you define a new transmitter set, its name is added in the '''Transmitters ''' section of the navigation tree. The color of all the base points associated with the newly defined transmitter set changes, and receivers adjusted above an uneven terrain surfaceadditional little ball with the transmitter color (red by default) appears at the location of each associated base point.You can open the property dialog of the transmitter set and modify a number of parameters including the '''Source Power''' in Watts and the broadcast signal '''Phase''' in degrees. The default transmitter power level is 1W or 30dBm. There is also a check box labeled '''Use Custom Input Power''', which is checked by default. In that case, the power and phase boxes are enabled and you can change the default 1W power and 0&deg; phase values as you wish. [[EM.Cube]] 's ".RAD" radiation pattern files usually contain the value of &quot;Total Radiated Power&quot; in their file header. This quantity is calculated based on the particular excitation mechanism that was used to generate the pattern file in the original [[EM.Cube]] module. When the "Use Custom Input Power" check box is unchecked, EM.Terrano will use the total radiated power value of the radiation file for the SBR simulation.  {{Note|In order to modify any of the transmitter set's parameters, first you need to select the "User Defined Antenna" option, even if you want to keep the vertical half-wave dipole as your radiator.}} <table><tr><td> [[ImageFile:prop_txrx2_tnNewTxProp.png|thumb|400pxleft|720px|The associated base property dialog of a point sets transmitter set.]]</td></tr></table> Your transmitter in EM.Teranno is indeed more sophisticated than a simple radiator. It consists of a basic "Transmitter Chain" that contains a voltage source with a series source resistance, and connected via a segment of transmission line to a transmit antenna, which is used to launch the adjusted transmitters broadcast signal into the free space. The transmitter's property dialog allows you to define the basic transmitter chain. Click the {{key|Transmitter Chain}} button of the Transmitter Set dialog to open the transmitter chain dialog. As shown in the figure below, you can specify the characteristics of the baseband/IF amplifier, mixer and receivers power amplifier (PA) including stage gains and impedance mismatch factors (IMF) as well as the characteristics of the transmission line segment that connects the PA to the antenna. Note that the transmit antenna characteristics are automatically filled using the contents of the imported radiation pattern data file. The transmitter Chain dialog also calculates and reports the "Total Transmitter Chain Gain" based on your input. When you close this dialog and return to the terrainTransmitter Set dialog, you will see the calculated value of the Effective Isotropic Radiated Power (EIRP) of your transmitter in dBm.]]In {{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:NewTxChain.png|thumb|left|720px|EM.CubeTerrano's point transmitter chain dialog.]]</td></tr></table> === Defining a Point Receiver Set in the Formal Way === Receivers act as observables in a propagation scene. The objective of a SBR simulation is to calculate the far-zone electric fields and the total received power at the location of a receiver. You need to define at least one receiver in the scene before you can run a SBR simulation. Similar to a transmitter, all a receiver is a point radiator, too. EM.Terrano gives you three options for the transmitters radiator associated with a point receiver set: * Half-wave dipole* Polarization matched isotropic radiator* User defined antenna pattern  By default, EM.Terrano assumes that your receiver is a vertically polarized (Z-directed) resonant half-wave dipole antenna. You can change the direction of the dipole and receivers are tied up orient it along the X or Y axes using the provided drop-down list. An isotropic radiator has a perfect omni-directional radiation pattern in all azimuth and elevation directions. An isotropic radiator doesn't exist physically in the real world, but it can be used simply as a point in space to compute the electric field.  You may also define a complicated radiation pattern for your receiver set. In that case, you need to import a radiation pattern data file to EM.Terrano similar to the case of a transmitter set.  {{Note|By default, EM.Terrano assumes a vertical half-wave dipole radiator for your point receiver set.}} 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. These All the receivers belonging to the same receiver set have the same radiator type. A typical propagation scene contains one or few transmitters but usually a large number of receivers. To generate a wireless coverage map, you need to define an array of points as your base location set.  [[Image:Info_icon.png|40px]] Click here to learn how to define a '''[[Glossary_of_EM.Cube%27s_Simulation_Observables_%26_Graph_Types#Point_Receiver_Set | Point Receiver Set]]'''. <table><tr><td> [[Image:Terrano L1 Fig12.png|thumb|left|480px|The point objects are grouped receiver set definition dialog.]] </td></tr></table> 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 receiver set changes, and organized in an additional little ball with the receiver color (yellow by default) appears at the location of each associated base setspoint. When you move You can open the property dialog of the receiver set and modify a number of parameters. <table><tr><td> [[File:NewRxProp.png|thumb|left|720px|The property dialog of a point objects or change their coordinatesreceiver set.]]</td></tr></table> In the Receiver Set dialog, there is a drop-down list labeled '''Selected Element''', which contains a list of all the individual receivers belonging to the receiver set. At the end of an SBR simulation, the button labeled {{key|Show Ray Data}} becomes enabled. Clicking this button opens the Ray Data dialog, where you can see a list of all the received rays at the selected receiver and their associated transmitters or computed characteristics.  If you choose the "user defined antenna" option for your receiver set, it indeed consists of a basic "Receiver Chain" that contains a receive antenna connected via a segment of transmission line to the low-noise amplifier (LNA) that is terminated in a matched load. The receiver set's property dialog allows you to define the basic receiver chain. Click the {{key|Receiver Chain}} button of the Receiver Set dialog to open the receiver chain dialog. As shown in the figure below, you can specify the characteristics of the LNA such as its gain and noise figure in dB as well as the characteristics of the transmission line segment that connects the antenna to the LNA. Note that the receiving antenna characteristics are automatically filled from using contents of the radiation file. You have to enter values for antenna's '''Brightness Temperature''' as well as the temperature of the transmission line and the receiver's ambient temperature. The effective '''Receiver Bandwidth''' is assumed to be 100MHz, which you can change for the purpose of noise calculations. The Receive Chain dialog calculates and reports the "Noise Power" and "Total Receiver Chain Gain" based on your input. At the end of an SBR simulation, the receiver power and signal-noise ratio (SNR) of the selected receiver are calculated and they are reported in the receiver set dialog in dBm and dB, respectively. You can examine the properties of all the individual receivers immediately follow them and all the individual rays received by each receiver in your receiver set using the "Selected Element" drop-down list.  <table><tr><td> [[File:NewRxChain.png|thumb|left|720px|EM.Terrano's point receiver chain dialog.]] </td></tr></table> === Modulation Waveform and Detection === EM.Terrano allows you to define a digital modulation scheme for your communication link. There are currently 17 waveforms to choose from in the new locationreceiver set property dialog: *OOK*M-ary ASK*Coherent BFSK*Coherent QFSK*Coherent M-ary FSK*Non-Coherent BFSK*Non-Coherent QFSK*Non-Coherent M-ary FSK*BPSK*QPSK*Offset QPSK*M-ary PSK*DBPSK*pi/4 Gray-Coded DQPSK*M-ary QAM*MSK*GMSK (BT = 0.3) In the above list, you need to specify the '''No. Levels (M)''' for the Mary modulation schemes, from which the '''No. Bits per Symbol''' is determined. You can also define a bandwidth for the signal, 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. The Shannon – Hartley Equation estimates the channel capacity: <math> C = B \log_2 \left( 1 + \frac{S}{N} \right) </math> where B in the bandwidth in Hz, and C is the channel capacity (maximum data rate) expressed in bits/s. The spectral efficiency of the channel is defined as <math> \eta = \log_2 \left( 1 + \frac{S}{N} \right) </math> The quantity E_b/N₀ is the ratio of energy per bit to noise power spectral density. It is a measure of SNR per bit and is calculated from the following equation: <math> \frac{E_b}{N_0} = \frac{ 2^\eta - 1}{\eta} </math> where &eta; is the spectral efficiency.  The relationship between the bit error rate and E_b/N₀ depends on the modulation scheme and detection type (coherent vs. non-coherent). For example, for coherent QPSK modulation, one can write: <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: <math> \text{erfc}(x) = 1-\text{erf}(x) = \frac{2}{\sqrt{\pi}} \int_{x}^{\infty} e^{-t^2} dt </math> The '''Minimum Required SNR''' parameter is used to determine link connectivity between each transmitter and receiver pair. If you usually define check the box labeled '''Generate Connectivity Map''' in the receiver set property dialog, a grid binary map of receivers using the propagation scene is generated by EM.Terrano, in which one color represents a base closed link and another represent no connection depending on the selected color map type of the graph. EM.Terrano also calculates the '''Max Permissible BER''' corresponding to the specified minimum required SNR and displays it in the receiver set property dialog. === A Note on EM.Terrano's Native Dipole Radiators === When you define a new transmitter set or a new receiver set, EM.Terrano assigns a vertically polarized half-wave dipole radiator to the set by default. The radiation pattern of this native dipole radiators is calculated using well-know expressions that are derived based on certain assumptions and approximations. For example, the far-zone electric field of a vertically-polarized dipole antenna can be expressed as:  <math> E_\theta(\theta,\phi) \approx j\eta_0 I_0 \frac{e^{-jk_0 r}}{2\pi r} \left[ \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] </math> <math> E_\phi(\theta,\phi) \approx 0 </math> where k₀ = 2&pi;/&lambda;₀ is made up 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 the dipole. The directivity of the dipole antenna is given be the expression: <math> D_0 \approx \frac{2}{F_1(k_0L) + F_2(k_0L) + F_3(k_0L)} \left[ \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]^2 </math> with  <math> F_1(x) = \gamma + \text{ln}(x) - C_i(x) </math> <math> F_2(x) = \frac{1}{2} \text{sin}(x) \left[ S_i(2x) - 2S_i(x) \right] </math> <math> F_3(x) = \frac{1}{2} \text{cos}(x) \left[ \gamma + \text{ln}(x/2) + C_i(2x) - 2C_i(x) \right] </math>  where &gamma; = 0.5772 is the Euler-Mascheroni constant, and C_i(x) and S_i(x) are the cosine and sine integrals, respectively:  <math> C_i(x) = - \int_{x}^{\infty} \frac{ \text{cos} \tau}{\tau} d\tau </math> <math> S_i(x) = \int_{0}^{x} \frac{ \text{sin} \tau}{\tau} d\tau </math>  In the case of a uniformly spaced array half-wave dipole, L = &lambda;₀/2, and D₀ = 1.643. Moreover, the input impedance of points the dipole antenna is Z_A = 73 + j42.5 &Omega;. These dipole radiators are connected via 50&Omega; transmission lines to a 50&Omega; source or load. Therefore, there is always a certain level of impedance mismatch that violates the conjugate match condition for maximum power.  <table><tr><td> [[File:Dipole radiators.png|thumb|720px|EM.Terrano's native half-wave dipole transmitter and spread them receiver.]] </td></tr></table> On 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 (&theta;, &phi;) angles. Besides 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 [[EM.Libera]]'s wire MOM solver. The names of the radiation pattern files are:  * DPL_STD_X.RAD* DPL_STD_Y.RAD* DPL_STD_Z.RAD and they are located in the folder "\Documents\EMAG\Models" on your scenecomputer. All of Note that these receivers have are full-wave simulation data and do not involve any approximate assumptions. To use these files as an alternative to the same height because their associated base points all have native dipole radiators, you need to select the same '''User Defined Antenna Pattern''' radio button as the the radiator type in the transmitter or receiver set property dialog. === A Note on the Rotation of Antenna Radiation Patterns === EM.Terrano's Transmitter Set dialog and Receiver Set dialog both allow you to rotate an imported radiation pattern. In that case, you need to specify the '''Rotation''' angles in degrees about the X-, Y- and Z-coordinateaxes. When your receivers It is important to note that these rotations are located above performed sequentially and in the following order: first a flat terrain like rotation about the global groundX-axis, their then a rotation about the Y-axis, and finally a rotation about the Z-coordinates axis. In addition, all the rotations are equal performed with respect to their height above the ground"rotated" local coordinate systems (LCS). In other words, as the terrain elevation first rotation with respect to the local X-axis transforms the XYZ LCS to a new primed X^&prime;Y^&prime;Z^&prime; LCS. The second rotation is fixed performed with respect to the new Y^&prime;-axis and equal transforms the X^&prime;Y^&prime;Z^&prime; LCS to zero everywherea new double-primed X^{&prime;&prime;}Y^{&prime;&prime;}Z^{&prime;&prime;} LCS. The same third rotation is true for transmitters, toofinally performed with respect to the new Z^{&prime;&prime;}-axis. The figures below shows single and double rotations.  <table><tr><td> [[File:PROP22B.png|thumb|300px|The local coordinate system of a linear dipole antenna.]] </td><td> [[File:PROP22C.png|thumb|600px|Rotating the dipole antenna by +90&deg; about the local Y-axis.]] </td></tr></table><table><tr><td> [[File:PROP22D.png|thumb|720px|Rotating the dipole antenna by +90&deg; about the local X-axis and then by -45&deg; by the local Y-axis.]] </td></tr></table> === Adjustment of Tx/Rx Elevation above a Terrain Surface ===

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

== Running <table><tr><td> [[Image:PROP MAN8.png|thumb|left|640px|A SBR Simulation ==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.]] </td></tr></table>

=== Discretizing the Propagation Scene =in EM.Terrano ==

In a typical SBR simulation, a ray is traced from the location of the source until it hits a scatterer. The [[SBR Method|SBR method]] assumes that the ray hits either a flat facet of the scatterer or one of its edges. If hitting a flat facet, the specular point is used === Why Do You Need to launch new reflected and transmitted rays. If hitting an edge, a large number of new diffracted rays are generated in Discretize the scene. Scene? ===

[[EM.Terrano]] allows you to draw any type of surface or solid CAD objects under impenetrable and penetrable surface groups or penetrable volumes. Some of these objects have flat faces such 's SBR solver uses a method known as boxes, pyramids, etc. Some others contain curved surfaces or curved boundaries such as cylinders, cones, etc. All the non-flat surfaces have to be discretized Geometrical Optics (GO) in conjunction with the form Uniform Theory of a collection of smaller flat facets. [[EM.Terrano]] uses a triangular surface mesh generator Diffraction (UTD) to discretize trace the non-flat surfacerays from their originating point at the source to the individual receiver locations. Unlike [[EMRays may hit obstructing objects on their way and get reflected, diffracted or transmitted.Cube]]'s other computational modules, EM.Terrano's SBR solver can only handle diffraction off linear edges and reflection from and transmission through planar interfaces. When an incident ray hits the surface mesh does not depend on of the operating wavelength. Its sole purpose is to discretize curved scatterers into obstructing object, a flat facets. Therefore, geometrical fidelity local planar surface assumption is made at the only criterion for specular point. The assumptions of linear edges and planar facets obviously work in the quality case of a SBR meshscene with cubic buildings and a flat global ground.

{{Note|Discretizing smooth In many practical scenarios, however, your buildings may have curved surfaces, or the terrain may be irregular. EM.Terrano allows you to draw any type of surface or solid geometric objects using such as cylinders, cones, etc. under impenetrable and penetrable surface groups or penetrable volumes. EM.Terrano's mesh generator creates a triangular surface mesh gives rise to a large number of small edges among all the facets that are simply objects in your propagation scene, which is called a facet mesh artifacts and should not be considered as diffracting edges.}} Even the walls of cubic buildings are meshed using triangular cells. This enables EM.Terrano to properly discretize composite buildings made of conjoined cubic objects.

=== Viewing & Modifying Unlike [[EM.Cube]]'s other computational modules, the density or resolution of EM.Terrano's surface mesh does not depend on the operating frequency and is not expressed in terms of the wavelength. The sole purpose of EM.Terrano's facet mesh is to discretize curved and irregular scatterers into flat facets and linear edges. Therefore, geometrical fidelity is the only criterion for the quality of a facet mesh. It is important to note that discretizing smooth objects using a triangular surface mesh typically creates a large number of small edges among the facets that are simply mesh artifacts and should not be considered as diffracting edges. For example, each rectangular face of a cubic building is subdivided into four triangles along the two diagonals. The four internal edges lying inside the face are obviously not diffracting edges. A lot of subtleties like these must be taken into account by the SBR Mesh ===solver to run accurate and computationally efficient simulations.

You can view and examine === Generating the discretized version of your scene objects as they are sent to the SBR simulation engine. To view the mesh, click the '''Mesh''' [[File:mesh_tool.png]] button of the Simulate Toolbar or select '''Simulate &gt; Discretization &gt; Show Mesh''', or use 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]]'s Normal View, 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 Facet Mesh''' item.===

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. To adjust the mesh The 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..EM.Terrano'''. This dialog provides a single [[parameters]]: s facet mesh generator is controlled by the '''Cell Edge Length'''.parameter, which has a is expressed in project length units. The default value mesh cell size of 100 project unitsmight be too large for non-flat objects. If you are already You may have to set a smaller cell edge length in the Mesh View Mode and open the EM.Terrano's Mesh Settings Dialogdialog, you can see along with a lower curvature angle tolerance value to capture the effect curvature of changing the edge length using the '''Apply''' button. Click OK to close the dialogyour curved structures adequately.

Note that unlike <table><tr><td> [[Image:prop_manual-29.png|thumb|left|480px|EM.Cube]]Terrano's other computational modules that express the default mesh density based on the wavelength, the resolution of the SBR mesh generator is expressed in project length units. The default edge length value of 100 units might be too large for non-flat objects. You may have to use a lower value to capture the curvature of your curved structures adequatelysettings dialog. ]] </td></tr></table>

[[FileImage:prop_manual-29Info_icon.png|30px]]Click here to learn more about '''[[Preparing_Physical_Structures_for_Electromagnetic_Simulation#Working_with_EM.Cube.27s_Mesh_Generators | Working with Mesh Generator]]'''.

Figure 1: [[Propagation ModuleImage:Info_icon.png|30px]]Click here to learn more about the properties of '''[[Glossary_of_EM.Cube%27s_Simulation-Related_Operations#Facet_Mesh | EM.Terrano's Facet Mesh Settings dialogGenerator]]'''.

== Running Ray Tracing Simulations in EM.Terrano offers three types of ray tracing simulations:==

A single-frequency * 3D Field Solver* SBR analysis is the simplest ray tracing simulation and involves the following steps:Channel Analyzer* Log-Haul Channel Analyzer* Communication Link Solver* Radar Link Solver

# Set the unit The first three simulation types are described below. For a description of project scene and the frequency of operation. Note that [[EM.Cube]]Terrano's default project unit is millimeter. When working with the [[Propagation Module]]Radar Simulator, pay attention to the project unit. Radio 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 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 simulation engine.# Visualize the coverage map and plot other datafollow this link.

You can access the [[Propagation Module]]'s run dialog by clicking the '''Run''' [[File:run_icon.png]] button of the '''Simulate Toolbar''' or by selecting '''Simulate &gt; Run...''' or using the keyboard shortcut '''Ctrl+R'''. When you click the '''Run''' button, === Running a new window opens up that reports the different stages of the Single-Frequency 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.Analysis ===

[[File:PROP12Its main solver is the '''3D SBR Ray Tracer'''.png]]Once you have set up your propagation scene in EM.Terrano and have defined sources/transmitters and observables/receivers for your scene, you are ready to run a SBR ray tracing simulation. You set the simulation mode in EM.Terrano's simulation run dialog. A single-frequency SBR analysis is a single-run simulation and the simplest type of ray tracing simulation in EM.Terrano. It involves the following steps:

Figure 1: [[Propagation Module]]* Set the units of your project and the frequency of operation. Note that the default project unit is 's Simulation ''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 dialogthe SBR simulation engine.* Visualize the coverage map and plot other data.

=== SBR You can access EM.Terrano's Simulation Parameters ===Run dialog by clicking the '''Run''' [[File:run_icon.png]] button of the '''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.

There are a number of SBR simulation settings that can be accessed and changed from the SBR Settings Dialog. To open this dialog, click the button labeled '''Settings''' on the right side of the '''Select Engine''' dropdown list in the Run Dialog. <table><tr><td> [[Image:Terrano L1 Fig16.png|thumb|left|480px|EM.Cube]]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 '''Ray Reflection''', '''Ray Transmission''' and '''Ray Diffraction'''. By default, all three effects are checked and included in the computations. Separating these effects sometimes help you better analyze your propagation scene and understand the impact of various blocks in the scenerun dialog.]] </td></tr></table>

<table><tr><td> [[Image:PROP MAN10.png|thumb|left|550px|EM.Cube]] requires a finite number of ray bounces for each original ray emanating from a transmitter. This is very important in situations that may involve resonance effects where rays get trapped among certain group of surfaces and may bounce back and forth indefinitely. This is set using the box labeled &quot;Terrano'''Max No. Ray Bounces'''&quot;, which has a default value of 10. Note that the maximum number of ray bounces directly affects the computation time as well as the size of s output simulation data filesmessage window. This can become critical for indoor propagation scenes, where most of the rays undergo a large number of reflections. ]] </td></tr></table>

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

You There are a number of SBR simulation settings that can also set 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 '''Angular ResolutionSelect Simulation or Solver Type''' of the transmitter rays drop-down list in degreesthe Run Dialog. By default, every transmitter emanates equi-angular ray tubes at a resolution of 1 degreeEM. Lower angular resolutions larger than 1° speed up the Terrano's SBR simulation significantly, but they may compromise engine allows you to separate the accuracyphysical effects that are calculated during a ray tracing process. Higher angular resolutions less than 1° increase You can selectively enable or disable '''Reflection/Transmission''' and '''Edge Diffraction''' in the accuracy "Ray-Block Interactions" section of the simulating resultsthis dialog. By default, but they also increase 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 computation timescene.

[[FileEM.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:PROP13'''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.png]]

Figure 1: <table><tr><td> [[Propagation Module]]Image:PROP MAN11.png|thumb|left|720px|EM.Terrano's SBR Engine Settings simulation engine settings dialog.]] </td></tr></table>

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

# By clicking EM.Terrano gives a few more options for the '''Frequency''' [[File:freq_iconray tracing solution of your propagation problem.png]] button For instance, it allows you to exclude the direct line-of -sight (LOS) rays from the '''Compute Toolbar'''final solution.# By selecting '''Compute''' [[File:larrow_tn.png]]'''Frequency Settings...''' There is a check box for this purpose labeled "Exclude direct (LOS) rays from the Menu Barsolution", which is unchecked by default.# Using EM.Terrano also allows you to superpose the keyboard shortcut '''Ctrl+F'''received rays incoherently.# By double clicking In that case, the frequency section (box) powers of individual ray are simply added to compute that total received power. This option in the '''Status Bar'''check box labeled "Superpose rays incoherently" is disabled by default, too.<br />

[[File:prop_freqAt the end of a ray tracing simulation, the electric field of each individual ray is computed and reported.png]] [[File:prop_run10By default, the actual received ray fields are reported, which are independent of the radiation pattern of the receive antennas.png]]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:

You It can also select be seen that if the ray'''Frequency Sweep''' option in the '''Simulation Mode''' drops E-down list of field is not normalized, the '''Run Dialog'''. Click the '''Settings...''' button on the right side of this dropdown list computed ray power will correspond to open up the Frequency Settings Dialog. Based on the original values of the project center frequency and bandwidth, the '''Start Frequency''' and '''End Frequency''' have default values. You can also change the '''Number of Samples'''. Once you click the '''Run''' button, [[EM.Cube|EM.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. All the simulation data at all frequency samples are saved into the output data files including &quot;SBR_results.RTOUT&quot;. After the completion of a frequency sweep simulation, as many coverage maps as the number of frequency samples are generated and added to the Navigation Tree under the Receiver Set's entry. 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 mapspolarization matched isotropic receiver.

=== Running a Parametric Sweep with SBR Polarimetric Channel Analysis ===

[[File:prop_run24In a 3D SBR simulation, a transmitter shoots a large number of rays in all directions.png|thumb|300px|EMThe electric fields of these rays are polarimetric and their strength and polarization are determined by the designated radiation pattern of the transmit antenna. The rays travel in the propagation scene and bounce from the ground and buildings or other scatterers or get diffracted at the building edges until they reach the location of the receivers. Each individual ray has its own vectorial electric field and power. The electric fields of the received rays are then superposed coherently and polarimetrically to compute the total field at the receiver locations. The designated radiation pattern of the receivers is then used to compute the total received power by each individual receiver.CUBE's variable dialog]]

[[File:prop_run23From a theoretical point of view, the radiation patterns of the transmit and receive antennas are independent of the propagation channel characteristics. For the given locations of the point transmitters and receivers, one can assume ideal isotropic radiators at these points and compute the polarimetric transfer function matrix of the propagation channel. This matrix relates the received electric field at each receiver location to the transmitted electric field at each transmitter location. In general, the vectorial electric field of each individual ray is expressed in the local standard spherical coordinate system at the transmitter and receiver locations. In other words, the polarimetric channel matrix expresses the '''E_&theta;''' and '''E_&phi;''' field components associated with each ray at the receiver location to its '''E_&theta;''' and '''E_&phi;''' field components at the transmitter location. Each ray has a delay and &theta; and &phi; angles of departure at the transmitter location and &theta; and &phi; angles of departure at the receiver location.png|thumb|250px|Dialog for defining new variables]]

In [[To perform a polarimatric channel characterization of your propagation scene, open EM.Cube]], all Terrano's Run Simulation dialog and select '''Channel Analyzer''' from the CAD object properties as well as certain sourcedrop-down list labeled '''Select Simulation or Solver Type'''. At the end of the simulation, material and mesh [[parameters]] can be assigned as [[variables]]a large ray database is generated with two data files called "sbr_channel_matrix. [[Variables]] are defined to control DAT" and vary "sbr_ray_path.DAT". The former file contains the values delay, angles of such [[parameters]] either arrival and departure and complex-valued elements of the channel matrix for editing purposes or to run parametric sweep or [[optimization]]all the individual rays that leave each transmitter and arrive at each receiver. Variable are defined using The latter file contains the '''[[Variables]] Dialog'''geometric aspects of each ray such as hit point coordinates.

=== Statistical Analysis of Propagation Scene The "Near Real-Time" Polarimatrix Solver ===

After EM.Terrano's coverage maps display the received power at the location of channel analyzer generates a ray database that characterizes your propagation channel polarimetrically for all the receivers. The receivers together from a set/ensemblecombinations of transmitter and receiver locations, which might be uniformly spaced or distributed across a ray tracing solution of the propagation scene or may consist problem can readily be found in almost real time by incorporating the effects of randomly scattered radiatorsthe radiation patterns of transmit and receive antennas. Every coverage map shows This is done using the '''MeanPolarimatrix Solver''' and , which is the third option of the drop-down list labeled '''Standard DeviationSelect Simulation or Solver Type''' of the received power for all the receivers involvedin EM. These information are displayed at the bottom of the coverage mapTerrano's legend box Run Simulation dialog. The results of the Polarimatrix and are expressed in dB3D 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.

In Using the [[Propagation Module]], when you ran Polarimatrix solver can lead to a sweep simulation (frequency or parametric), you also have the option to generate two additional coverage maps: one for the mean significant reduction of all the individual sample coverage maps and another for their standard deviation. To do so, total simulation time in the '''Run Dialog''', check the box labeled '''&quot;Create Mean and Standard Deviation Coverage Maps&quot;'''. Note sweep simulations that the mean involve a large number of transmitters 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 correspond to frequency, transmitter or variable sets defined for the sweep . Certain simulationmodes of EM. Also, note that both of Terrano are intended for the mean and standard deviation coverage maps have their own spatial mean and standard deviation values expressed Polarimatrix solver only as will be described in dB at the bottom of their legend boxnext section.

[[File:prop_run21_tn{{Note| In order to use the Polarimatrix solver, you must first generate a ray database of your propagation scene using EM.png]]Terrano's Channel Analyzer.}}

The mean coverage map at the end of a transmitter sweep=== EM.Terrano's Simulation Modes ===

[[File:prop_run22_tnEM.png]]Terrano provides a number of different simulation modes that involve single or multiple simulation runs:

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

If the associated radiator set is isotropic, so will be the transmitter set{{Note| EM. By default, an isotropic transmitter has vertical polarization. You can use Terrano's frequency sweep simulations are very fast because the '''Polarization''' radio button to select one geometrical optics (ray tracing) part of the two options: '''Vertical''' or '''Horizontal'''. If the associated radiator set consists of '''Short Dipole''' or '''User Defined''' radiators, it simulation is indicated in the transmitter property dialogfrequency-independent. In the case of a short dipole radiator, you can set a value for the dipole current in Amperes. The radiation resistance of a short dipole of length ''dl'' is given by:}}

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

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.Terrano assumes all to be coherent with respect to one another. In other words, synchronous transmitters are always assumed. The radiated power of rays originating from all these transmitters are superposed coherently and vectorially at each receiver. In a short dipole carrying transmitter sweep, on the other hand, EM.Terrano assumes only one transmitter broadcasting at a current I₀ time. The result of the sweep simulation is then given by:a number of received power coverage maps, each corresponding to a transmitter in the scene.

:<math> P_{rad} = \frac{1}{2} R_r Note|I_0|^2 = 40\pi^2 |I_0|^2 \left( \frac{dlEM.Terrano's transmitter sweep works only with the Polarimatrix Solver and requires an existing ray database previously generated using the Channel Analyzer.}{\lambda_0} \right)^2 </math><!--[[File:shortdipole.png]]-->

In a regular SBR simulation, you have a transmitter and one or more arrays of receivers in your scene. At You can rotate the end 3D radiation patterns of both the simulation, you can visualize transmitters and receivers from the coverage map property dialog of the parent transmitter over the set or receiver setsset. A coverage map shows the total '''Received Power''' by each of the receivers and This is visualized as done in advance before a color-coded intensity plotSBR simulation starts. You can visualize define one or more of the coverage maps rotation angles of individual a transmitter set or a receiver setsset as sweep variables and perform a parametric sweep simulation. At In that case, the end entire scene and all of its buildings are discretized at each simulation run and a complete physical SBR ray tracing simulation, each Received Power Coverage Map is listed under the receiver set's name in the Navigation Treecarried out. To display a coverage mapHowever, simply click on its entry in we know that the Navigation Tree. The coverage map plot appears in polarimetric characteristics of the Main Window overlaid on propagation channel are independent of the scenetransmitter or receiver antenna patterns or their rotation angles. A legend box on rotational sweep allows you to rotate the right shows radiation pattern of the color scale and units transmitter(dBs)about one of the three principal axes sequentially. The 3-D coverage maps are displayed as horizontal confetti above This is equivalent to the receiverssteering of the beam of the transmit antenna either mechanically or electronically. If The result of the receivers are packed close to each other, you will see sweep simulation is a continuous confetti map. If the receivers are far apart, you will see individual colored squares. You can also visualize number of received power coverage maps as colored 3-D cubes. This may be useful when you set up your receivers in a vertical arrangement or , each corresponding to one of the scene has a highly uneven terrainangular samples. To change the type of coverage map visualizationrun a rotational sweep, open you must specify 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 dialogrotation angle.

[[File:prop_run11_tn.png{{Note|400px]] [[File:prop_run12_tnEM.png|400px]]Terrano's rotational sweep works only with the Polarimatrix Solver and requires an existing ray database previously generated using the Channel Analyzer.}}

You can change the settings of the coverage map by right clicking on its entry In a mobile sweep, each transmitter is paired with a receiver according to their indices in the Navigation Tree and selecting '''Properties.their parent sets..''' or by double-clicking on the legend box. In the Output Plot Settings dialogAt each simulation run, you can choose from only one of three Color Map options: '''Default'''(Tx, '''Rainbow''' and '''Grayscale'''. The visualization plot uses default values for Rx) pair is considered to be active in the color scalescene. In the section titled &quot;Limits&quot;As a result, you can choose the radio button labeled '''User Defined'''generated coverage map takes a different meaning implying the sequential movement of the transmitter and receiver pair along their corresponding paths. ThenIn other words, you have to enter new values for the '''Lower''' set of point transmitters and '''Upper''' Limits the set of point receivers indeed represent the plotlocations of a single transmitter and a single receiver at different instants of time. You can also show or hide It is obvious that the Legend Box or change its '''Background''' total number of transmitters and '''Foreground''' colors by clicking total number of receivers in the buttons provided for this purposescene must be equal. Otherwise, EM.Terrano will prompt an error message.

[[File:prop_run4EM.pngCube]]provides a '''Mobile Path Wizard''' that facilitates the creation of a transmitter set or a receiver set along a specified path. This path can be an existing nodal curve (polyline or NURBS curve) or an existing line objects. You can also import a sptial Cartesian data file containing the coordinates of the base location points. For more information, refer to [[Glossary_of_EM.Cube%27s_Wizards#Mobile_Path_Wizard | Mobile Path Wizard]].

=== Visualizing the Rays in the Scene Investigating Propagation Effects Selectively One at a Time ===

In a typical SBR ray tracing simulation, EM.Terrano includes all the propagation effects such as direct (LOS) rays, ray reflection and transmission, and edge diffractions. At the end of a SBR simulation, each receiver receives a number of rays. Some receivers may not receive any rays at all. You you can visualize all the rays received by a certain receiver from the active transmitter power coverage map of the your propagation scene. To do this, right click which appears under the '''Receivers''' receiver set item of in the Navigation Treenavigation tree. From The figure below shows the context menu select '''Show Received Rays'''. All the rays received by the currently selected receiver power coverage map of the random city scene are displayed in with a vertically polarized half-wave dipole transmitter located 10m above the scene. The rays are identified by labels, are ordered by their power ground 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 large grid of all the individual vertically polarized half-wave dipole receivers belonging to that setplaced 1. To display 5m above the rays received by another receiver, you have to change ground. The legend box shows the '''Selected Receiver''' in limits of the receiver set's property dialog. If you keep color map between -23dBm as the mouse focus on this dropdown list maximum and roll your mouse scroll wheel, you can scan -150dB (the selected receivers and move the rays from one default 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 sensitivity value) as the context menu select '''Hide Received Rays'''minimum.

<table><tr><td> [[FileImage:prop_run5_tnUrbanCanyon10.png|800pxthumb|left|640px|The received power coverage map of the random city scene with a dipole transmitter.]]</td></tr></table>

Visualization Sometime it is helpful to change the scale of the color map to better understand the dynamic range of the coverage map. If you double-click on the legend or right-click on the coverage map's name in the navigation tree and select '''Properties''', the Plot Settings dialog opens up. Select the '''User-Defined''' item and set the lower and upper bounds of color map as you wish. <table><tr><td> [[Image:UrbanCanyon15.png|thumb|left|480px|The plot settings dialog of the coverage map.]] </td></tr></table><table><tr><td> [[Image:UrbanCanyon16.png|thumb|left|640px|The received power coverage map of the random city scene with a user-defined color map scale between -80dBm and -20dBm.]] </td></tr></table> To better understand the various propagation effects, EM.Terrano allows you to enable or disable these effects selectively. This is done from the Ray Tracing Simulation Engine Settings dialog using the provided check boxes.  <table><tr><td> [[Image:UrbanCanyon14.png|thumb|left|640px|EM.Terrano's simulation run dialog showing the check boxes for controlling various propagation effects.]] </td></tr></table> <table><tr><td> [[Image:UrbanCanyon11.png|thumb|left|640px|The received power coverage map of the random city scene with direct LOS rays only.]] </td></tr><tr><td> [[Image:UrbanCanyon12.png|thumb|left|640px|The received power coverage map of the random city scene with reflected rays only.]] </td></tr><tr><td> [[Image:UrbanCanyon13.png|thumb|left|640px|The received power coverage map of the random city scene with diffracted rays only.]] </td></tr></table> == Working with EM.Terrano's Simulation Data == === The Ray Tracing Solvers' Output Simulation Data === Both the SBR solver and the Polarimatrix solver perform the same type of simulation but in two different ways. The SBR solver discretizes the scene including all the buildings and terrain, shoots a large number of rays from the transmitters and collects the rays at the receivers. The Polarimatrix solver does the same thing using an existing polarimetric ray database that has been previously generated using EM.Terrano's Channel Analyzer. It incorporates the effects of the radiation patterns of the transmit and receive antennas in conjunction with the polarimetric channel characteristics. At the end of a ray tracing simulation, all the polarimetric rays emanating from the transmitter(s) or other sources that are received by the individual receivers are computed, collected, sorted and saved into ASCII data files. From the ray data, the total electric field at the location of receivers as well as the total received power are computed. The individual ray data include the field components of each ray, the ray's elevation and azimuth angles of departure and arrival (departure from the transmitter location and arrival at the receiver location), and time delay of the received ray with respect to the transmitter. If you specify the temperatures, noise figure and transmission line losses in the definition of the receiver sets, the noise power level and signal-to-noise ratio (SNR) at each receiver are also calculated, and so are the E_b/N₀ and bit error rate (BER) for the selected digital modulation scheme. === Visualizing Field & Received Power Coverage Maps === In wireless propagation modeling for communication system applications, the received power at the receiverlocation is more important than the field distributions. In order to compute the received power, you need three pieces of information: * '''Total Transmitted Power (EIRP)''': This requires knowledge of the baseband signal power, the transmitter chain parameters, the transmission characteristics of the transmission line connecting the transmitter circuit to the transmitting antenna and the radiation characteristics of the transmitting antenna.* '''Channel Path Loss''': This is computed through SBR simulation. * '''Receiver Properties''': This includes the radiation characteristics of the receiving antenna, the transmission characteristics of the transmission line connecting the receiving antenna to the receiver circuit and the receiver chain parameters. In a simple link scenario, the received power P_r in dBm is found from the following equation: <math> P_r [dBm] = P_t [dBm] + G_{TC} + G_{TA} - PL + G_{RA} + G_{RC} </math> where P_t is the baseband signal power in dBm at the transmitter, G_TC and G_RC are the total transmitter and receiver chain gains in dB, respectively, G_TA and G_RA are the total transmitting and receiving antenna gains in dB, respectively, and PL is the channel path loss in dB. Keep in mind that EM.Terrano is fully polarimetric. The transmitting and receiving antenna characteristics are specified through the imported radiation pattern files, which are part of the definition of the transmitters and receivers. In particular, the polarization mismatch losses are taken into account through the polarimetric SBR ray tracing analysis.  If you specify the noise-related parameters of your receiver set, the signal-to-noise ratios (SNR) is calculated at each receiver location: SNR = P_r - P_n, where P_n is the noise power level in dB. When planning, designing and deploying a communication system between points A and B, the link is considered to be closes and a connection established if the received signal power at the location of the receiver is above the noise power level by a certain threshold. In other words, the SNR at the receiver must be greater than a certain specified minimum SNR level. You specify (SNR)_min ss part of the definition of receiver chain in the Receiver Set dialog. In the "Visualization Options" section of this dialog, you can also check the check box labeled '''Generate Connectivity Map'''. This is a binary-level black-and-white map that displays connected receivers in white and disconnected receivers in black. At the end of an SBR simulation, the computed SNR is displayed in the Receiver Set dialog for the selected receiver. The connectivity map is generated and added to the navigation tree underneath the received power coverage map node.  At the end of an SBR simulation, you can visualize the field maps and receiver power coverage map of your receiver sets. A coverage map shows the total '''Received Power''' by each of the receivers and is visualized as a color-coded intensity plot. Under each receiver set node in the navigation tree, a total of seven field maps together with a received power coverage map are added. The field maps include amplitude and phase plots for the three X, Y, Z field components plus a total electric field plot. To display a field or coverage map, simply click on its entry in the navigation tree. The 3D plot appears in the Main Window overlaid on your propagation scene. A legend box on the right shows the color scale and units (dB). The 3D coverage maps are displayed as horizontal confetti above the receivers. You can change the appearance of the receivers and maps from the property dialog of the receiver set. You can further customize the settings of the 3D field and coverage plots.  <table><tr><td>[[Image:AnnArbor Scene1.png|thumb|left|640px|The downtown Ann Arbor propagation scene.]]</td></tr><tr><td>[[Image:AnnArbor Scene2.png|thumb|left|640px|The electric field distribution map of the Ann Arbor scene with vertical dipole transmitter and receivers.]]</td></tr><tr><td>[[Image:AnnArbor Scene3.png|thumb|left|640px|The received power coverage map of the Ann Arbor scene with vertical dipole transmitter and receivers.]]</td></tr><tr><td>[[Image:AnnArbor Scene4.png|thumb|left| 640px |The connectivity map of the Ann Arbor scene with SNR_min = 3dB with the basic color map option.]]</td></tr><tr><td>[[Image:AnnArbor Scene5.png|thumb|left| 640px |The connectivity map of the Ann Arbor scene with SNR_min = 20dB with the basic color map option.]]</td></tr></table> === Visualizing the Rays in the Scene === At the end of a SBR simulation, each receiver receives a number of rays. Some receivers may not receive any rays at all. You can visualize all the rays received by a certain receiver from the active transmitter of the scene. To do this, right click the '''Receivers''' item of the Navigation Tree. From the context menu select '''Show Received Rays'''. All the rays received by the currently selected receiver of the scene are displayed in the scene. The rays are identified by labels, are ordered by their power and have different colors for better visualization. You can display the rays for only one receiver at a time. The receiver set property dialog has a list of all the individual receivers belonging to that set. To display the rays received by another receiver, you have to change the '''Selected Receiver''' in the receiver set's property dialog. If you keep the mouse focus on this dropdown list and roll your mouse scroll wheel, you can scan the selected receivers and move the rays from one receiver to the next in the list. To remove the visualized rays from the scene, right click the Receivers item of the Navigation Tree again and from the context menu select '''Hide Received Rays'''.

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

{{Note: The |All the received rays are summed up coherently in a vectorial manner at the receiverlocation.}}

<table><tr><td> [[FileImage:prop_run6_tnUrbanCanyon18.png|800pxthumb|left|640px|Visualization of received rays at the location of a selected receiver in the random city scene.]]</td></tr></table>

Figure=== 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: Analyzing  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 selected receiver has the following information: * Ray Index* Delay in nsec* &theta; and &phi; Angles of Arrival in deg* &theta; and &phi; Angles of Departure in deg* Real and imaginary parts of the three E_x, E_y, E_z components* Number of ray from hit points * Coordinates 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. <table><tr><td> [[Image:prop_run8_tn.png|thumb|left|720px|A typical SBR output data dialogfile.]]</td></tr></table>

Besides visualizing the coverage map and received rays "sbr_results.out", [[EM.Terrano]] writes a number of other ASCII data files to your project folder. You can view or plot these data in the [[EM.Cube|EM.CUBE]]'s [[Propagation Module]], you Data Manager. You can also plot open data manager by clicking the '''Path LossData Manager''' [[File:data_manager_icon.png]] button of all the receivers belonging to a receiver set as well as the '''Power Delay ProfileSimulate Toolbar''' of individual receivers. To plot these data, go the or by selecting '''ObservablesMenu > Simulate > Data Manager''' section of from the Navigation Tree and menu bar or by right click -clicking on the '''ReceiversData Manager''' item. From of the context menu, select navigation tree and selecting '''Plot Path LossOpen Data Manager...''' from the contextual menu or '''Plot Power Delay Profile''', respectively. The path loss data between the active transmitter and all the receivers belonging to a receiver set are plotted on a Cartesian graph. The horizontal axis of this graph represents the index of the receiver. Power Delay Profile is a bar chart that plots the power of individual rays received by using the currently selected receiver versus their time delay. If there is a line of sight (LOS) between a transmitter and receiver, the LOS ray will have the smallest delay and therefore will appear first in the bar chart. Sometimes you may have several rays arriving at a receiver at the same time, i.e. all with the same delay, but with different power level. These will appear as stacked bars in the chartkeyboard shortcut {{key|Ctrl+D}}.

You can also plot the path loss and power delay profile graphs and many others from [[EM.Cube|EM.CUBE]]'s The available data manager. You can open data manager by clicking files in the '''"2D Data Manager''' [[File:data_manager_icon.png]] button Files" tab 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 Manger include the theta and phi angles of arrival and departure of the selected receiver. You can select any data file by clicking and highlighting its '''ID''' in the table and then clicking the '''Plot''' button.:

* '''Path Loss''': The channel path loss is defined as PL === Output P_r - EIRP. The path loss data are stored in a file called "SBR_receiver_set_name_PATHLOSS.DAT" as a function of the receiver index. The path loss data make sense only if your receiver set has the default isotropic radiator. * '''Power Delay Profile''': The 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.DAT". You can plot these data from the Data Files ===Manager as a bar chart called the power delay profile. The bars indeed correspond to the difference between the ray power in dBm and the minimum power threshold level in dBm, which makes them a positive quantity. * '''Angles of Arrival''': These are the Theta and Phi angles of the individual rays received by the selected receiver and saved to the files "SBR_receiver_set_name_ThetaARRIVAL.ANG" and "SBR_receiver_set_name_PhiARRIVAL.ANG". You can plot them in the Data Manager in polar stem charts.

At the end When you run a frequency or parametric sweep in [[EM.Terrano]], a tremendous amount of an SBR simulationdata may be generated. [[EM.Terrano]] only stores the '''Received Power''', '''Path Loss''' and '''SNR''' of the results are written into a main output selected receiverin ASCII data file with files called "PREC_i.DAT", "PL_i.DAT" and "SNR_i.DAT", where is the reserved name index of SBR_Resultsthe receiver set in your scene.RTOUTThese quantities are tabulated vs. This file has the following format:sweep variable's samples. You can plot these files in EM.Grid.

NEW LINE[[Image:Info_icon.png|40px]] Click here to learn more about working with data filed and plotting graphs in [[EM.Cube]]'s '''[[Defining_Project_Observables_%26_Visualizing_Output_Data#The_Data_Manager | Data Manager]]'''.

Number When you designate a "User Defined Antenna Pattern" as the radiator type of Raysa 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 actual location of the transmitter or receiver. To do so, you have to define a 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 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 scene.

NEW LINE<table><tr><td>[[Image:UrbanCanyon6.png|thumb|left|640px|The received power coverage map of the random city scene with a highly directional dipole array transmitter.]]</td></tr></table>

* Ray Number* &By Default, [[EM.Cube]] 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; Angles components of Arrival 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 dega 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. * &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 &phiangle increments are both 1&deg; Angles of Departure in degthis case. The radiation pattern has been elevated by 10m to be positioned at the location of the transmitter and a scaling factor of 0.3 has been used. * Delay in nsec* Real(E<suptable>V<tr><td>[[Image:UrbanCanyon8.png|thumb|left|640px|Setting the pattern parameters in the radiation pattern dialog.]]</suptd>) &amp; Imag(E<sup/tr>V</suptable>)* Real(E<suptable>H<tr><td>[[Image:UrbanCanyon7.png|thumb|left|720px|Visualization of the 3D radiation pattern of the directional transmitter in the random city scene.]]</suptd>) &amp; Imag(E<sup/tr>H</suptable>)* Real(There is an important catch to remember here. When you define a radiation pattern observable for 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 radiation patterns'''E.eThis 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).  <subtable>R<tr><td>[[Image:UrbanCanyon9.png|thumb|left|640px|EM.Terrano's Run Simulation dialog.]]</subtd></tr></table> == Using EM.Terrano as an Asymptotic Field Solver == Like every other electromagnetic solver, EM.Terrano's SBR ray tracer requires an excitation source and one or more observables for the generation of simulation data. EM.Terrano offers several types of sources and observables for a SBR simulation. You already learned about the transmitter set as a source and the receiver set as an observable. You can mix and match different source types and observable types depending on the requirements of your modeling problem.  The available source types in EM.Terrano are: {| class="wikitable"|-! scope="col"| Icon! scope="col"| Source Type! scope="col"| Applications! scope="col"| Restrictions|-| style="width:30px;" | [[File:transmitter_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 &ampOther Physical Object Types#Hertzian Short Dipole Source | Hertzian Short Dipole]]| style="width:250px; Imag(" | 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|} Click on each type to learn more about it in the [[Glossary of EM.Cube's Materials, Sources, Devices & Other Physical Object Types]].  The available observables types in [[EM.Terrano]] are: {| class="wikitable"|-! scope="col"| Icon! scope="col"| Source Type! scope="col"| Applications! scope="col"| Restrictions|-| style="width:30px;" | [[File:receiver_icon.png]]| style="width:150px;" | [[Glossary of EM.Cube'Es 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 be associated with a base location point set|-| style="width:30px;" | [[File:Distr Rx icon.epng]]| style="width:150px;" | [[Glossary of EM.Cube's Simulation Observables & Graph Types#Distributed Receiver Set | Distributed Receiver Set]]| style="width:250px;" | Computing received power at a receiver characterized by Huygens surface data| style="width:250px;" | None, stand-alone source imported from a Huygens surface data file|-| style="width:30px;" | [[File:fieldsensor_icon.png]]| style="width:150px;" | [[Glossary of EM.Cube's Simulation Observables & Graph Types#Near-Field Sensor Observable | Near-Field Sensor]]| style="width:250px;" | Generating electric and magnetic field distribution maps| style="width:250px;" | None, stand-alone observable|-| style="width:30px;" | [[File:farfield_icon.png]]| style="width:150px;" | [[Glossary of EM.Cube's Simulation Observables & Graph Types#Far-Field Radiation Pattern Observable | Far-Field Radiation Pattern]]| style="width:250px;" | Computing the effective radiation pattern of a radiator in the presence of a large scattering scene | style="width:250px;" | None, stand-alone observable|-| style="width:30px;" | [[File:huyg_surf_icon.png]]| style="width:150px;" | [[Glossary of EM.Cube's 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 [[Glossary of EM.Cube'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.  {{Note| Computing radiation patterns using EM.Terrano's SBR solver typically takes much longer computation times than using [[EM.Cube]]'s other computational modules.}} <subtable>R<tr><td> [[Image:SBR pattern.png|thumb|540px|Computed 3D radiation pattern of two vertical short dipole radiators placed 1m apart in the free space at 1GHz.]] </subtd></tr></table> == Statistical Analysis of Propagation Scene == 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 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.* PowerWhen 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 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> [[Image:PROP MAN12.png|thumb|left|480px|EM.Terrano's simulation run dialog showing frequency sweep as the simulation mode along with statistical analysis.]] </td></tr></table> <table><tr><td> [[Image:UrbanCanyon4.png|thumb|left|640px|The mean coverage map at the end of a frequency sweep.]] </td></tr><tr><td> [[Image:UrbanCanyon5.png|thumb|left|640px|The standard deviation coverage map at the end of a frequency sweep.]] </td></tr></table> <br />

[[FileImage:prop_run8_tnTop_icon.png|800px30px]]'''[[EM.Terrano#Product_Overview | Back to the Top of the Page]]'''

Figure[[Image: A typical SBR output data fileTutorial_icon.png|30px]] '''[[EM.Cube#EM.Terrano_Documentation | EM.Terrano Tutorial Gateway]]'''

<p>&nbsp;</p>[[Image:Back_icon.png|30px]] '''[[EM.Cube | Back to EM.Cube Main Page]]'''