CAT
Set properties for a Close Approach computation.
Syntax
CAT <ObjectPath> {Option}
Related commands
Description
Use the CAT command to set the properties for a Close Approach computation. Use the CAT_RM command to compute the Close Approach. This command is valid for Satellite, LaunchVehicle, and Missile only.
The following tables describe the command options.
You must enter each option on a separate command line.
| {Option} | Description |
|---|---|
| LaunchWindow {TimeInterval} | Specify the time interval during which the vehicle may initiate its trajectory.
For valid {TimeInterval} values see Time Options. |
| Range <Value> | Specify a value corresponding to the minimum allowable distance between the reference object and any other object. Enter the <Value> in Connect distance units. The value should be greater than 0.0 m. |
The following table describes the Advanced options.
| Advanced {Options} | Description |
|---|---|
| Database "<FilePath>" | Specify the satellite Database file to be used. If you specify a database with an *.sd extension, descriptions for the close approach objects are automatically included when the object is created. If you specify a database with a *.tce extension, descriptions aren't included. You can use any file containing GP element data, including TLE files and files containing CCSDS OMM content in XML, KVN, (using file extension .omm), and CSV formats. By default, CAT searches the stkAllTLE satellite database. "<Filename>" can be the path to a file on your local drive or the path to a file on an SDF server. See Specifying Paths for "<SDFFilePath>" syntax information. |
| XRefDatabase {On | Off | "<FilePath>"} | Specify a secondary database to augment that found in the standard TLE database. For example, if the SSC number of the satellite is 16609, the cross-reference feature gives you the common name 'Mir.'
"<Filename>" can be the path to a file on your local drive or the path to a file on an SDF server. See Specifying Paths for "<SDFFilePath>" syntax information. |
| Filter {FilterType} [{On | Off | <DistanceValue>}] | Using the CAT Filter command enables you to tune preliminary filters that limit the amount of ephemeris generated to compute close approaches for an object. The proper use of these preliminary filters can greatly reduce the amount of time needed for close approach processing. These pads are added to the <RangeVal> constraint specified with the CAT_RM Connect command. {FilterType} can be:
The default <DistanceValue> for all {FilterTypes} is 30 km. Enter it in Connect distance units. |
| AddThreats {On | Off} [<MaxToAdd>] | This option enables you to add satellites to the scenario and, therefore, to close approach calculations. The command adds conjuncting satellites, i.e., candidate satellites that closely approach the reference vehicle, to the STK scenario when calculations occur.
Use the <MaxToAdd> value to limit the number of Satellites added to the scenario. If On is entered, you must specify a <MaxToAdd> value. <MaxToAdd> is an integer between 1 to 99999. |
| SetModelScale <Scale> | Specify the model scale for Satellites added to the Scenario. Use the AddThreats option to indicate whether or not satellites are added to the Scenario. <Scale> is a real number between 0.0 and 10.0. |
| AccessGfx {LineState} {AnimateHighlightState} {StaticHighlightState} | Set graphics that appear during a close approach. You must specify all three parameters in the exact order shown here. Valid values for state parameters are On and Off. |
| Routine {SGP4 | Default | <Name>} | Specify the implementation of the SGP4 propagator to be used, where SGP4 is the internal SGP4 routine implemented by STK, Default is the propagator selected in the Edit Preferences panel, and <Name> is an installed SGP4 plugin routine, e.g., ASTROSTDS_SGP4_V9.
Astro Standards routines may be available as options if you properly configured STK to support it. It is only available if you have obtained the official SGP4 DLL (and related files) from USSF (US Space Force) and performed a minor install procedure. STK provides an interface to USSF SGP4 routines; contact customer support for more information. In the past, you may have used this command to choose the USGovMSGP4 routine. This is no longer necessary, as the implementation of the internal SGP4 routine and the USGov routine have been made the same. Routine names are case sensitive. When you choose a different propagator for close approach, it does NOT change the propagator used for the vehicle. The change only affects close approach functions and doesn't impact STK. |
Examples
To set access graphics so that close approaches are highlighted using a thick line overlaying the ground tracks and only display when you're not animating:
To set the number of candidate satellites to add to 100:
To set an apogee/perigee pad of 30,000 m for the ERS1 satellite, which has a maximum range value of 5000 m:
To set a 45 minute launch window for the TestMissile:
To change the propagator so that an Astro Standards routine is used during close approach calculations instead of the standard SGP4 routine:
To use the stkAllComm.sd database as a cross-reference lookup for TLE data:
The use the STK SGP4 routine:
Return message
Group membership
This command belongs to the following group(s):
Version
11.6