RF Loss Constraints
Environmental factors can affect the performance of a communications link or a radar system. An object's RF Environment properties page enables you to apply RF Environment models to your analyses. The models will affect all RF phenomena in the scenario, except where overridden or varied on the individual STK object.
When you add an RF Loss constraint to an object and select the Enable check box for it, the models will affect all RF phenomena in the scenario involving that object. RF Loss is available for Receiver and Radar objects.
The following are the RF Loss constraints available on the Constraints - Active properties page:
| Constraint | Description |
|---|---|
| Atmospheric Loss | For a description of applicable models, see Atmospheric Absorption. |
| Clouds Fog Loss | For a description of applicable models, see Rain, and clouds & fog. |
| Free Space Loss | This is signal loss due to propagation through space. The equation is one the Environmental and Loss Factors help page. |
| Iono Fading Loss | This is propagation loss due to the signal passing through the ionosphere. For a description of applicable models, see Ionospheric propagation fading loss model. |
| System Noise Temperature |
You have two main options to specify this constraint:
|
| Total Propagation Loss |
This option is only available if the Calculate option is selected on the radar or receiver Definition properties page AND the Calculated option with at least one Component is selected in the System Temperature dialog AND if you specified a Min and/or Max System Noise Temperature. If you select this option, STK ignores the specification of individual RF Loss constraints and simply applies the total system noise temperature calculated by STK in constraint evaluation. |
| Rain Loss | For a description of applicable models, see Rain, and clouds & fog. |
| Tropo Scintillation Loss | For a description of applicable models, see Tropospheric scintillation. |
| Urban Terrestrial Loss | For a description of applicable models, see Urban and terrestrial. |
| Custom A/B/C Loss | You can enable up to three custom losses that you specify. See Custom models. |