Facility, Place, Target & Vehicle Atmosphere RF Properties

The Communications and Radar Modules add an Atmosphere page to the RF Properties for facilities, places, targets and all vehicles except satellites. The fields on this page specify the local surface atmospheric conditions used by the gaseous absorption and rain models.

To set local values for gaseous absorption, clear Inherit under Atmospheric Absorption Model, select the desired atmospheric absorption model and specify details in the same manner as you would at the scenario level.

The rainfall rate used by the selected rain model is normally determined on the basis of the ground location and the desired annual outage percentage. The statistical rainfall rate may be overridden with local rain data by selecting Enable under Local Rain Data and entering the following information:

Local rain data options

Type	Description
Rain Height	Maximum atmospheric height at which rain is present.
Rain Rate for 0.01% of Time	Amount of rain per unit of time; e.g., in millimeters per hour.
Surface Temperature	Surface temperature.

Overriding the global (scenario) values may be desired when you are trying to model real-world conditions at a particular time or when more accurate rain data is available based on local rain statistics than through the application of the global statistics.

If you override the scenario values by setting the atmospheric or rain model properties on:

Both ends of the communications link (transmit and receive), the atmospheric or rain model specified for the receiver's parent is used.
Just one end of the communications link (either transmit or receive), the atmospheric or rain model specified for the parent of that one end is used.

If you do not override the model on the transmit or receive end, then the scenario RF Environment properties are used.

The local surface values set at the facility, place, target, and vehicle level override values set at the scenario level.