Changes

* '''[[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 locate a single transmitter or receiver or arrays of transmitters or receivers in the scene.

=== Adding a New Scene Element ===