Like every other electromagnetic solver, EM.Terrano's SBR ray tracer requires an excitation source and one or more observables for generation of simulation data. EM.Terrano offers several types of sources and observables for a SBR simulation. You can mix and match different source types and observable types depending on the requirements of your modeling problem. The available source types are:
* '''[[#Defining Transmitter Sets | Transmitter]]'''* '''[[#Defining_a_Hertzian_Dipole_Source | Hertzian Dipole]]'''
The available observables types are :
* '''[[#Defining Receiver Sets | Receiver]]'''* '''[[#Defining_a_Hertzian_Dipole_Source | Field Sensor]]'''* '''[[#Computing_Radiation_Patterns_In_SBR | Far Field Radiation Pattern]]'''* '''[[Hybrid_Modeling_using_Multiple_Simulation_Engines#Generating_Huygens_Surface_Data | Huygens Surface]]'''
A short dipole source is the simplest type of excitation for your propagation scene. A short dipole has an almost "omni-directional" radiation pattern, and is the closest thing to an isotropic radiator. EM.Terrano does not provide a theoretical/hypothetical isotropic transmitter because its SBR solver is fully polarimetric and requires a real physical radiator for ray generation. A transmitter is a more sophisticated source that requires a base point as well as an imported radiation pattern file with a '''.RAD''' file extension.
{{Note| In order to define Of the above list of EM.Terrano's observables types, receivers are the ones you would typically use for your propagation scenes. Unlike a transmitter, you need to import a receiver by default does not require an imported radiation pattern file from one of [[. A default receiver is assumed to be polarization-matched to the incoming ray. The other three observable types, field sensor, far fields and Huygens surface are primarily used in applications that utilize EM.CubeTerrano as an asymptotic electromagnetic field solver. The Huygens surface observable is primarily used for [[Hybrid Modeling using Multiple Simulation Engines|hybrid modeling using multiple simulation engines]]'s other computational modules.}}
Of the above list of EM.Terrano's observables types{{Note| In order to define either transmitters or receivers, receivers are the ones first you would typically use for your propagation sceneshave to define base points. Unlike For a transmitter, you additionally need to import a receiver by default does not require an imported radiation pattern file. A default receiver is assumed to be polarization-matched to the incoming ray. The other three observable types, field sensor, far fields and Huygens surface are primarily used in applications that utilize EM.Terrano as an asymptotic electromagnetic field solver. Â from one of [[Image:Info_iconEM.png|40pxCube]] Click here to learn more about '''[[Hybrid_Modeling_using_Multiple_Simulation_Engines#Generating_Huygens_Surface_Data | Generating Huygens Surface Data]]'''s other computational modules.}}
== Defining Transmitters & Receivers for Your Propagation Scene ==