=== 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. In [[EM.Terrano]], a transmitter represents a point source, while a receiver represents a point observable. Both a transmitter and a receiver are associated with point objects, which are one of the many types of geometric objects you can draw in the project workspace. Your scene might involve more than one transmitter and possibly a large grid of receivers.
A more complicated propagation scene usually contains several buildings, walls, or other kinds of scatterers and wave obstructing objects. You models model all of these elements 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 common type of interaction with incident rays. [[EM.Terrano]] offer the following types of object blocks:
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