Set properties for a launch window analysis.
LaunchWindow <ObjectPath> {Option}
Use the LaunchWindow command to set the properties for a launch window analysis. Use the LaunchWindow_RM command to compute the Launch Window.
Note: This command is valid for LaunchVehicle and Missile only.
The following tables describe the command options.
Note: Currently, each option must be entered 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.
The <Value> is entered in Connect distance units, and should be greater than 0.0m. |
| UseSecondaryEphemerisFiles {On | Off} | If On is entered then specify a folder
containing ephemeris files to be used as reference for the close
approach analysis. Use the UseScenarioForSecondaryEphemerisFiles
and SecondaryEphemerisFolder options.
If Off is entered then a set of TLE files will be used and and the SGP4 propagator will be used to calculate their ephemerides for the close approach analysis. Use the Database and XRefDatabase options to select the TLE files. |
| UseScenarioForSecondaryEphemerisFiles {On | Off} | Enter On to use the Scenario folder to search for secondary ephemeris files. If Off is entered use the SecondaryEphemerisFolder option to select a folder. |
| SecondaryEphemerisFolder <FolderName> | Enter the folder name to be searched for secondary ephemeris files. This option will be used if UseScenarioForSecondaryEphemerisFiles if Off. |
| Database "<FilePath>" | Specify the satellite Database file to
be used.
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. |
| 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.' |
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.
The <Value> is entered in the Connect time unit, and must be greater or equal to 0.0 seconds. |
| LaunchTrajectoryMETInterval {<Start> <Stop> | EntireTrajectory} | To evaluate potential conjunctions you
can specify either <Start> <Stop> or EntireTrajectory.
<Start> and <Stop> are entered in Connect time units, and valid values depend on the vehicle ephemeris. |
| CreateSatellites {On | Off} [<MaxToAdd>] | This option allows satellites to be
added 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 are computed.
If On is entered, you must specify the <MaxToAdd> value to limit the number of Satellites added to the scenario. <MaxToAdd> is an integer between 0 to 100000. |
| 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> is entered in Connect time unit, 0.001 to 1200.00 seconds |
| TSRMaxStep <Value> | Specify the maximum sampling step for
sampling points along the launch trajectory.
The <Value> is entered in Connect time unit, 0.001 to 1200.00 seconds |
| TSRMaxRelMotion <Value> | Specify the maximum angular motion to
allow between sample times of the secondary ephemeris.
The <Value> is entered in degrees, 0.001 to 60.00 degrees. |
| Filter {FilterType} [{On | Off | <Value>}] |
Using the CAT Filter command allows 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. Note: If you set UseLaunchArea to On, you must set the LaunchMETOffset to 0.0. |
| Propagator {Routine} | Choose a different implementation of
the SGP4 routine for use during close approach calculations only.
Different SGP4 implementations (other than the internal SGP4
routine implemented by STK) may or may not be available to you,
depending on your STK install configuration. You can determine if
different routines are available by creating a satellite, choosing
the SGP4 propagator, and noting whether a combobox appears on the
panel listing names of routines. If no combobox appears, then the
only available routine is the internal routine supplied by STK.
Note: Routine names are case sensitive. Note: 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> is entered in degrees, and is between -180.0 and 180.0 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 are entered in the Connect distance unit, and are 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> are integers, between 1 and 10000. |
| AreaLaunchWindowStep <Value> | Specify the sampling step size for
sampling of launch times within the launch window.
The <Value> is entered in Connect time unit, 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> is entered in Connect time unit, 0.001 to 1200.00 seconds |
| AreaTSRMaxRelMotion <Value> | Specify the maximum angular motion to
allow between sample times of the secondary ephemeris.
The <Value> is entered in degrees, 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> is entered in the Connect time unit, and is 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> is entered in the Connect time unit, and is between 0.0001 and 600.0 seconds. |
| CreateLaunchMTO {On | Off} | If UseLaunchArea is On then specify 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. |
To set the number of candidate satellites to add to 100:
LaunchWindow */Missile/TestMissile CreateSatellites On 100
To set an apogee/perigee pad of 30,000 m for the TestMissile:
LaunchWindow */Missile/TestMissile Filter ApogeePerigee 30000
To set a 45 minute launch window for the TestMissile:
LaunchWindow */Missile/TestMissile LaunchWindow "1 Jan 2000 10:01:00.00" "1 Jan 2000 10:46:00.00"
To set the range for TestMissile to 50km:
LaunchWindow */Missile/TestMissile Range 50000
To set the LaunchVehicle to use a TLE file and to use the stkAllComm.sd database as a cross-reference lookup for TLE data:
LaunchWindow */LaunchVehicle/Lv12 UseSecondaryEphemerisFiles Off
LaunchWindow */LaunchVehicle/Lv12 XRefDatabase "C:\stk\User\Database\stkAllComm.sd"
If activated, Connect returns an acknowledgement message.
This command belongs to the following group(s):
10
STK Programming Interface 11.0.1