LaunchWindow
Set properties for a launch window analysis.
Syntax
LaunchWindow <ObjectPath> {Option}
Related commands
Description
Use the LaunchWindow command to set the properties for a launch window analysis. Use the LaunchWindow_RM command to compute the Launch Window.
This command is valid for LaunchVehicle and Missile only.
The following tables describe the command options.
You must enter each option on a separate command line.
The following table describes the main options.
| Main {Options} | Description |
|---|---|
| LaunchWindow {TimeInterval} | Specify the time interval during which a missile or launch 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> greater than 0.0 m in Connect distance units. |
| UseSecondaryEphemerisFiles {On | Off} | If you enter On, then specify a folder containing ephemeris files for STK to use as reference for the close approach analysis. Use the UseScenarioForSecondaryEphemerisFiles and SecondaryEphemerisFolder options.
If you enter Off, then STK will use an external file of GP data (like TLEs) and the SGP4 propagator to calculate the ephemerides for the close approach analysis. Use the Database and XRefDatabase options to select the GP data file. |
| UseScenarioForSecondaryEphemerisFiles {On | Off} | Enter On to use the Scenario folder to search for secondary ephemeris files. If you enter Off, use the SecondaryEphemerisFolder option to select a folder. |
| SecondaryEphemerisFolder <FolderName> | Enter the folder name to be searched for secondary ephemeris files. STK will use this option if UseScenarioForSecondaryEphemerisFiles is Off. |
| Database "<FilePath>" | Specify the satellite Database file for STK to use. If you specify a database with a *.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. "<FilePath>" 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.'
"<FilePath>" 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. |
The following table describes the Advanced options.
| Advanced {Options} | Description |
|---|---|
| LaunchMETOffset <Value> | Define the Mission Elapsed Time at the beginning of the subject vehicle's ephemeris. Enter the <Value> in the Connect time unit; it must be greater than or equal to 0.0 seconds. |
| LaunchTrajectoryMETInterval {<Start> <Stop> | EntireTrajectory} | To evaluate potential conjunctions, you can specify either <Start> <Stop> or EntireTrajectory.
Enter <Start> and <Stop> in Connect time units; valid values depend on the vehicle ephemeris. |
| CreateSatellites {On | Off | <MaxToAdd>} | If you include CreateSatellites and enter On, then STK will add conjuncting satellites — candidate satellites that closely approach the reference vehicle — to the scenario when it computes close approach.
The <MaxToAdd> value will limit the number of Satellites added to the scenario. <MaxToAdd> is an integer between 0 to 100000. If you enter <MaxToAdd>, then STK will change CreateSatellites to On. |
| SetModelScale {On | Off | <Scale>} | Specify the model scale for Satellites added to the Scenario. Use the AddThreats option to indicate whether Satellites are added to the Scenario. <Scale> is a real number between 0.0 and 10.0. |
| LaunchWindowStep <Value> | Specify the step size for sampling of launch times within the launch window. The <Value> range is 0.001 to 1200.00 seconds, entered in Connect time units. |
| TSRMaxStep <Value> | Specify the maximum sampling step for sampling points along the launch trajectory. The <Value> range is 0.001 to 1200.00 seconds, entered in Connect time units. |
| TSRMaxRelMotion <Value> | Specify the maximum angular motion to allow between sample times of the secondary ephemeris. The <Value> range is 0.001 to 60.00 degrees, entered in degrees. |
| Filter {FilterType} [{On | Off | <Value>}] | 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:
|
| UseLaunchArea {On | Off} | Specify On to define the launch location as occurring within a rectangular area relative to the reference launch trajectory. Specify Off to define the launch location as occurring at a specific point.
See the Table below for options used to define the Launch Area. If you set UseLaunchArea to On, you must set the LaunchMETOffset to 0.0. |
| 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 an option if STK has been properly configured 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 the USSF SGP4 routines; contact customer support for more information. 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. |
The following table describes the Launch Area options.
| Launch Area {Options} | Description |
|---|---|
| LaunchAreaOrientation {North | Velocity} <Azimuth> | Specify the launch area's direction of alignment. Enter an <Azimuth> value to rotate the launch area off of the aligned direction. <Azimuth> has a range between -180.0 and 180.0 degrees, entered in degrees. |
| TargetSameStop {On | Off} | Specify On to require that each trajectory will target the same endpoint as the reference launch trajectory. |
| LaunchAreaAltReference {Ellipsoid | Terrain | MSL} | Specify the altitude reference. |
| LaunchAreaSize <XMin> <XMax> <YMin> <YMax> | Define the boundaries of the launch area. The values must be in the Connect distance unit and between -1000.0 km and 1000.0 km. <XMin> must be less than <XMax> and <YMin> must be less than <YMax>. |
| LaunchAreaSampling <XSamples> <YSamples> | Specify the number of samples that will be taken along the launch area's axes. <XSamples> and <YSamples> must be integers between 1 and 10000. |
| AreaLaunchWindowStep <Value> | Specify the sampling step size for sampling of launch times within the launch window. The <Value> must be in the Connect time unit and in the range 0.001 to 1200.00 seconds. |
| AreaTSRMaxStep <Value> | Specify the maximum sampling step for sampling points along the launch trajectory. A smaller maximum step is usually required for a launch area than for a fixed launch site, to achieve accuracy when considering a launch from anywhere within the launch area.
The <Value> must be in Connect time units and in the range 0.001 to 1200.00 seconds. |
| AreaTSRMaxRelMotion <Value> | Specify the maximum angular motion to allow between sample times of the secondary ephemeris. The <Value> must be in degrees, from 0.001 to 60.00 degrees. |
The following table describes the Graphics options.
| Graphics {Options} | Description |
|---|---|
| ShowLaunchArea {On | Off} | Specify On to create an Area Target of the launch location. |
| ShowLaunchBlackoutTracks {On | Off} | Specify On to create two MTO objects for each blackout interval computed by the tool and display the tracks in the 2D and 3D Graphics windows. |
| BlackoutColor {Color} | Specify a color for the blackout tracks.
For valid {Color} options, see Common Options. |
| ShowLaunchClearedTracks {On | Off} | Specify On to create two MTO objects for each clear interval computed by the tool and display the tracks in the 2D and 3D Graphics windows. |
| UseObjectForClearedColor {On | Off} | Specify On to use the subject vehicle's display color for the clear interval tracks. |
| ClearedColor {Color} | Specify a color for the clear interval tracks.
For valid {Color} options, see Common Options. |
| ShowTrackSegments {On | Off} | Specify On to display ephemeris lines as well as markers for the tracks. |
| UsePrimaryStepSizeForTracks {On | Off} | Specify On to use the step size of the reference vehicle for the ephemeris display. |
| TrackTimeStep <Value> | Specify the step size for the ephemeris display. The <Value> must be in the Connect time units and between 0.001 and 86400.0 seconds. |
| ShowMinRangeTracks {On | Off} | Specify On to display the current point on the surface that is nearest to the secondary object that is causing the current blackout interval. |
| MinRangeTrackTimeStep <Value> | Reduce the step size to attempt to eliminate oscillation or increase it to improve calculation performance. The <Value> must be in the Connect time unit and between 0.0001 and 600.0 seconds. |
| CreateLaunchMTO {On | Off} | If UseLaunchArea is On, then specify CreateLaunchMTO as On to create an MTO object for the sample trajectories that are evaluated by the tool. |
| LaunchAreaVisualSampling <XSamples> <YSamples> | Specify the number of additional launch trajectories to create along the X and Y directions of the launch area.
<XSamples> and <YSamples> are integers between 1 and 10000. |
Examples
To turn On creation of conjuncting satellites and set the maximum number to add to 100:
To set an apogee/perigee pad of 30,000 m for the TestMissile:
To set a 45 minute launch window for the TestMissile:
To set the range for TestMissile to 50km:
To set the LaunchVehicle to use a TLE file and to use the stkAllComm.sd database as a cross-reference lookup for TLE data:
Return message
Group membership
This command belongs to the following group(s):
Version
11.6