Set Advanced CAT properties
ACAT <AdvCatObjPath> {CalculateOptions} <Parameters>
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. |
| Primary {Action} "<ObjFileName>" [{Options}] | {Action} can be:
The "<ObjFileName>" specified must be an existing file with a .sa, .e, .pg, .tce, .tle extension. Also, .itc is a valid extension if the user has a USGOV license. If the "<ObjFileName>" does not include a path STK will search the following directories for the file:
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. If {Action} is Add then "<ObjFileName>" is the only required parameter. If no other parameters are specified, STK uses defaults for those values. See table below for additional options for Primary and Secondary. If {Action} is Remove or RemoveAll no other parameters are needed. RemoveAll will empty the specified list (either Primary or Secondary). |
| Secondary {Action} "<ObjFileName>" [{Options}] | |
| Threshold <DistanceValue> | <DistanceValue> is entered in
Connect distance units. Valid value is between 0 and 1000 km.
Note: 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. |
| Propagator <NameOfPropagator> | This option allows you to choose a different implementation of the SGP4 propagator for use during ACAT calculations. Different SGP4 implementations (other than the internal SGP4 propagator implemented by STK) may or may not be available to you, depending on your STK install configuration. Propagator names are case sensitive. When you choose a different propagator for ACAT, it does not change the propagator used for the vehicle; the change only affects ACAT functions and does not further 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 {Options}:
| {Options} | 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. |
Hint: 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:
ACAT */AdvCAT/MyAdvCAT Primary Add "ERS1.sa" 21000.0 11000.0 6000.0
To use an orbit path prefilter of 123.4 kilometers:
ACAT */AdvCAT/MyAdvCAT PreFilters OrbitPath 123.4
To remove all entries from the Primary list for MyACat:
ACat */AdvCAT/MyACat Primary RemoveAll
To add three Primary objects to the list for MyAdvCAT:
ACat */AdvCAT/MyAdvCAT Primary Add "Covar50.sa" 21000.0 11000.0 6000.0 StringID ADBC NumberID 1234
ACAT */AdvCAT/MyAdvCAT Primary Add "Sat50.e" OrbitClass StringID ADBC
ACAT */AdvCAT/MyAdvCAT Primary Add "Sat1.pg" NumberID 1234 HardBodyRadius 200.0
To add a satellite from the current scenario as a Secondary object:
ACat */AdvCAT/MyAdvCAT Secondary Add "Satellite/TestSat2"
If activated, Connect returns an acknowledgement message.
This command belongs to the following group(s):
10
STK Programming Interface 11.0.1