Starting in STK 9, the Comm Connect commands, including Atmosphere, were enhanced to make use of attributes and to simplify the format required to use these commands. The Atmosphere Connect commands now enable you to get and set attribute values using the following formats:
To get attribute values and information from an object's Atmosphere data:
Atmosphere_RM <ObjectPath> GetValue [<AttributePath>]
To set attribute values for an object's Atmosphere data:
Atmosphere <ObjectPath> SetValue <AttributePath> <Value> [<Unit>]
The new Comm Connect commands use an attribute path to identify the location - within the Comm object extension - of the targeted attribute. The exact syntax and length of the attribute path depends upon the individual attribute. Each part of the attribute path must be separated by a period (.), including the attribute itself.
Further descriptions of the command syntax can be found here: Atmosphere and Atmosphere_RM.
The following command examples show how to switch over to the new Atmosphere command format from the old STK 8 format.
To use the atmospheric rain model defined on the scenario's RF Environment properties page in calculations for the Perth facility.
In STK 8, this command sets the RainModel override, height (in m), rate (in mm/hr) and temperature (in degC) for the Facility Perth:
Atmosphere */Facility/Perth RainModel OverrideOn 2800.0 29.0 30.0
In STK 9 or later, you can first use the Atmosphere_RM GetValue command to get the name and current setting of the Facility's atmosphere attributes. Numeric values are displayed in internal units. "Read-only" attributes can not be changed.
Atmosphere_RM */Facility/Perth GetValue
UserComment = STK Atmosphere Extension
InheritAtmosAbsorptionModel = true
AtmosAbsorptionModel = Simple_Satcom (Read-only)
AtmosAbsorptionModel.UserComment = Simple Satcom gaseous absorption model (Read-only)
AtmosAbsorptionModel.SurfaceTemperature = 293.15000000 K (Read-only)
AtmosAbsorptionModel.WaterVaporConcentration = 7.50000000 g*m^-3 (Read-only)
EnableLocalRainData = false
LocalRainIsoHeight = 2000.00000000 m (Read-only)
LocalRainRate = 1.00000000 mm*hr^-1 (Read-only)
LocalSurfaceTemp = 293.15000000 K (Read-only)
Use the Atmosphere command with the SetValue option to set the Facility to use local rain data. This will also remove the Read-only property from the local rain data attributes so that they can be modified:
Atmosphere */Facility/Perth SetValue EnableLocalRainData true
The following set of commands will set the attributes. For numeric values include the abbreviation of the unit that the value is being entered in, if it is different from the internal unit:
Atmosphere */Facility/Perth SetValue
LocalRainIsoHeight 2.80 km
Atmosphere */Facility/Perth SetValue LocalRainRate 29.0
Atmosphere */Facility/Perth SetValue LocalSurfaceTemp 86.0 degF
To use the Simple Satcom Absorption model in calculations for the Perth facility.
In STK 8, this command turns off inherit for the Absorption model, then sets the model type and the water vapor concentration (in g/m^3) and temperature (in degC) parameters:
Atmosphere */Facility/Perth Absorption InheritOff "Simple Satcom" 8.34 17.34
In STK 9 or later, first use the Atmosphere SetValue command to set the InheritAtmosAbsorptionModel attribute to false:
Atmosphere */Facility/Perth SetValue InheritAtmosAbsorptionModel false
Use the Atmosphere_RM GetValue command, specifying the AtmosAbsorptionModel attribute to get the current settings of the Facility's atmosphere attributes. Note that the AtmosAbsorptionModel attributes are no longer Read-only since the model is not being inherited.
Atmosphere_RM */Facility/Perth GetValue AtmosAbsorptionModel
AtmosAbsorptionModel = Simple_Satcom
AtmosAbsorptionModel.UserComment = Simple Satcom gaseous absorption model
AtmosAbsorptionModel.SurfaceTemperature = 293.15000000 K
AtmosAbsorptionModel.WaterVaporConcentration = 7.50000000 g*m^-3
Our Absorption model is already set to Simple_Satcom, so we only need to send the commands to set water vapor concentration and temperature:
Atmosphere */Facility/Perth SetValue
AtmosAbsorptionModel.WaterVaporConcentration 8.34
Atmosphere */Facility/Perth SetValue
AtmosAbsorptionModel.SurfaceTemperature 17.34 degC
Use the Atmosphere_RM GetValue command to see all the modified settings.
Atmosphere_RM */Facility/Perth GetValue
UserComment = STK Atmosphere Extension
InheritAtmosAbsorptionModel = false
AtmosAbsorptionModel = Simple_Satcom
AtmosAbsorptionModel.UserComment = Simple Satcom gaseous absorption model
AtmosAbsorptionModel.SurfaceTemperature = 290.49000000 K
AtmosAbsorptionModel.WaterVaporConcentration = 8.34000000 g*m^-3
EnableLocalRainData = true
LocalRainIsoHeight = 2800.00000000 m
LocalRainRate = 29.00000000 mm*hr^-1
LocalSurfaceTemp = 303.15000000 K
To change the Absorption model.
In STK 8, all the parameters must be entered on the command line, even though just the model is being changed:
Atmosphere */Facility/Perth Absorption InheritOff "ITU-R P.676-5" UseFastOn UseSeasonOn
In STK 9 or later, if necessary, use the Atmosphere_RM GetValue command with the Choices option on the AtmosAbsorptionModel attribute to get the available Absorption Model names:
Atmosphere_RM */Facility/Perth GetValue AtmosAbsorptionModel:Choices
ITU-R_P676-5
Script_Plugin
Simple_Satcom
TIREM_3.31
ITU-R_P676-3
TIREM_3.10
TIREM_3.16
TIREM_3.20
Change the Absorption model:
Atmosphere */Facility/Perth SetValue AtmosAbsorptionModel ITU-R_P676-5
Each Absorption model has it's own attributes. After changing the Absorption model you might want to use the Atmosphere_RM GetValue command with the AtmosAbsorptionModel attribute to see the attributes available for the current Absorption model.
Atmosphere_RM */Facility/Perth GetValue AtmosAbsorptionModel
AtmosAbsorptionModel = ITU-R_P676-5
AtmosAbsorptionModel.UserComment = ITU-R P676-5 gaseous absorption model
AtmosAbsorptionModel.UseApproxMethod = true
AtmosAbsorptionModel.UseSeasonalRegional = true
STK Programming Interface 11.0.1