ACAT
Set Advanced CAT properties
Syntax
ACAT <AdvCatObjPath> {CalculateOptions} <Parameters>
Description
The ACAT Connect command allows you to set properties for an Advanced Close Approach Tool search, including time period, threshold and analysis objects. It also allows you to compute close approaches once these parameters have been set.
{CalculateOptions} and <Parameters> can be:
| {CalculateOptions} | Description |
|---|---|
| Compute [ShowProgress {On | Off}] | Launch the close approach analysis. If ShowProgress is set to On, then a progress indicator will be displayed during the AdvCAT computations. The default for ShowProgress is Off. |
| TimePeriod {TimeInterval} | Enter the time period for the close approach analysis. For valid {TimeInterval} values see Time Options. |
| Propagator {Routine} | Specify the propagator (SGP4, Default, or a plugin name ex. AFSPC_SGP4_V8). If Default is selected, the propagator selected in the Edit Preferences panel is used. You can use the UI Advanced panel to ensure the setting worked. You may have to close the tool in order to see the propagator refresh. The panel only accepts a user setting if you compute. |
| Primary {Parameters} | {Parameters} can be one of:
The "<ObjFileName>" specified must be an existing file with a .sa, .e, .pg, .tce, .tle, .itc, .11param, .sp3, .alm, .al3, .yuma, .sem, .csv, .xml, .omm extension. If the "<ObjFileName>" does not include a path STK will search the following directories for the file (note: this does not apply if the "<ObjFileName>" is an SDF filepath):
Use the GetDirectory command to get your directory locations. The "<ObjFileName>" can also be the truncated path of an object in the current scenario, for example Satellite/Satellite1. See table below for the optional {AdditionalParams} for Primary Add and Secondary Add. RemoveAll will empty the specified list (either Primary or Secondary). |
| Secondary {Parameters} | |
| Threshold <DistanceValue> | <DistanceValue> is entered in Connect distance units. Valid value is between 0 and 1000 km.
Connect allows for threshold values larger than 1000.00 km. However, values above 1000.0 km have not been validated by AGI; Connect allows them to be used at the customer's discretion. |
| PreFilters {OutOfDate | ApogeePerigee | OrbitPath | Time} {On | Off | <Value>} | If PreFilters is OutOfDate then <Value> is a time added to the beginning and end of the analysis period. Valid value is between 1 day and 3650 days, entered in Connect Time units. If PreFilters is ApogeePerigee, OrbitPath or Time, then <Value> is a distance. Valid value is between 0.0 and 100000.0 km, entered in Connect Distance units. |
| XRefDbase {On | Off | "<FilePath>"} | Set the cross reference database file. |
| 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. AFSPC_SGP4_V8.
The AFSPC_SGP4 routine 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 AFSPC (Air Force Space Command) and performed some minor install procedure. STK provides an interface to the AFSPC SGP4 routine - contact customer support. 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. |
| ScaleFactor <ScaleValue> | Specify the ellipsoid scaling factor. Valid value is a real number greater than 0. |
| QuadDB "<FilePath>" | Specify the ellipsoid database files. |
| FixedOCDB "<FilePath>" | |
| QuadOCDB "<FilePath>" | |
| PntToPnt {On | Off} | When enabled, STK performs the close approach computation using range between objects as the criterion rather than the ellipsoid separation. |
| SampleStepSize <MaxValue> <MinValue> | Enter the maximum and minimum step sizes in Connect time units. |
| RemoveSecondaryBySSC {On | Off} | Specify whether to remove secondaries matching the primary SSC number. |
| AllowPartialEphem {On | Off} | Specify whether an object with an ephemeris that does not span the entire analysis interval will still be processed. |
| ForceReprop {On | Off} | Specify whether to force repropagation on load. |
| ComputeOnLoad {On | Off} | Specify whether to compute on load. |
| ConjTcaMode {GlobalOnly | LocalOnly | GlobalPlusLocal | LocalPlusEndPoints} | Specify the Conjunction mode for Time of Closest Approach.
GlobalOnly is standard AdvCAT behavior GlobalPlusLocal adds all relative minima as separate events with different ConjTCA values LocalOnly won't report a global that is an endtime LocalPlusEndPoints reports all local plus startTime if range is increasing and stoptime if range is decreasing |
Any of the following optional parameters can be included for the Primary or Secondary Add {AdditionalParams}:
The {AdditionalParams} must be entered in the following order:
[{Class}] [{<Tangential> <CrossTrack> <Normal>}] [{AllOtherParams}]
"<FilePath>" or "<ObjFileName>", when it represents a file name, 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.
| {AdditionalParams} | Description |
|---|---|
| {Class} | Valid values for {Class} are Fixed, OrbitClass, Quadratic, QuadOrb, Cov and CovOffset. Default value is Fixed. Note: Cov refers to Covariance. |
| <Tangential> <CrossTrack> <Normal> | All three values must be entered together. These values are entered in Connect distance units. |
| NumberID <NumberValue> | <NumberValue> is a positive integer. |
| StringID <StringValue> | <StringValue> is a character string. |
| HardBodyRadius <RadiusValue> | <RadiusValue> is real number between 0.0 and 100000.0. This value is entered in meters. |
Examples
Some Connect examples use units other than the Connect default units. Default units in Connect are: Distance = meters, Time = seconds, Date = Gregorian UTC. To change the default units for a Connect session, use the SetUnits command.
To add the ERS1 satellite to the list of primary objects for an Advanced CAT calculation and provide a tangential value of 21000.0, a CrossTrack value of 11000.0 and a Normal value of 6000.0:
To use an orbit path prefilter of 123.4 kilometers:
To remove all entries from the Primary list for MyACat:
To add three Primary objects to the list for MyAdvCAT:
To add a satellite from the current scenario as a Secondary object:
The end of this command uses SGP4. You can also use Default or AFSPC_SGP4_V8:
Return message
Group membership
This command belongs to the following group(s):
Version
11.6