=== The Various Elements of a Propagation Scene ===
A typical propagation scene in EM.Terrano consists of several elements. At a minimum, you need a transmitter (Tx) at some location to launch rays into the scene and a receiver (Rx) at another location to receive and collect the incoming rays. A transmitter and a receiver together make the simplest propagation scene, representing a free-space line-of-sight (LOS) channel. A transmitter is one of In EM.Terrano's several TErrano, a transmitter represents a point source types, while a receiver is represents a point observable. Both a transmitter and a receiver are associated with point objects, which are one of EM.Terrano's several observable the many typesof geometric objects you can draw in the project workspace. A simpler source type is Your scene might involve more than one transmitter and possibly a Hertzian dipole representing an almost omni-directional radiatorlarge grid of receivers. Â A simpler observable is a field sensor that is used to compute the electric more complicated propagation scene usually contains several buildings, walls, or other kinds of scatterers and magnetic fields wave obstructing objects. You models all of these by drawing geometric objects in the project workspace or by importing external CAD models. EM.Terrano does not organize the geometric objects of your project workspace by their material composition. Rather, it groups the geometric objects into blocks based on a specified planecommon type of interaction with incident rays.EM.Terrano offer the following types of object blocks: Â {| class="wikitable"|-! scope="col"| Block Type! scope="col"| Ray Interaction Type! scope="col"| Object Types Allowed|-| [[Glossary of EM.Cube's Materials & Physical Object Types#Impenetrable Surface | Impenetrable Surface]]| Reflection, diffraction| All solid & surface geometric objects, no curve objects|-| [[Glossary of EM.Cube's Materials & Physical Object Types#Penetrable Surface | Penetrable Surface]]| Reflection, diffraction, thin-wall transmission| All solid & surface geometric objects, no curve objects|-| [[Glossary of EM.Cube's Materials & Physical Object Types#Terrain Surface | Terrain Surface]]| Reflection, diffraction| All surface geometric objects, no solid or curve objects |-| [[Glossary of EM.Cube's Materials & Physical Object Types#Penetrable Volume | Penetrable Volume]]| Reflection, diffraction, material medium transmission| All solid geometric objects, no surface or curve objects|-| [[Glossary of EM.Cube's Materials & Physical Object Types#Base Location Set | Base Location Set]]| Ray genertaion or ray reception| Only point objects|}Â
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, a ceiling 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 in the scene. Your transmitters and receivers can be placed outdoors or indoors. A complete list of the various elements of a propagation scene is given in the '''Physical Structure''' section of EM.Terrano's Navigation Tree as follows (click on each type to learn more about it):