Description

Allows the user to configure and propagate a vehicle using the GPS propagator.

Object Model

Public Methods

Propagate

Propagates the satellite's path using the specified time interval.

Public Properties

AutoUpdate	Allows configuring the auto-update parameters and settings. AutoUpdateEnabled must be set to true in order to be able to change the auto-update properties.
AutoUpdateEnabled	Whether automatic update is enabled.
AvailablePRNs	Returns an array of available satellite Ids
EphemerisInterval	The propagator's ephemeris interval.
PRN	The satellite PRN number per ICD-GPS-200. This is a required data item as it is the GPS user's primary means of identifying GPS satellites. It is equivalent to the space vehicle identification (SVID) number of the satellite.
SpecifyCatalog	Specify a catalog. AutoUpdateEnabled must be set to false in order to select an almanac.
StartTime	This property is deprecated. Use EphemerisInterval to configure the propagation interval. Start time. Uses DateFormat Dimension.
Step	Step size. Uses Time Dimension.
StopTime	This property is deprecated. Use EphemerisInterval to configure the propagation interval. Stop time. Uses DateFormat Dimension.
UseScenarioAnalysisTime	This property is deprecated. Use the new Timeline API components to configure the propagator's analysis time. Whether the scenario analysis start/stop times shall be used.

Interfaces

Implemented Interface
IAgVePropagator

Example

Set the satellite to use the GPS propagator

[C#] Copy Code

// Set propagator to GPS 

satellite.SetPropagatorType(AgEVePropagatorType.ePropagatorGPS); 

 

// Get the GPS propagator 

IAgVePropagatorGPS propagator = satellite.Propagator as IAgVePropagatorGPS;

Configure the GPS propagator with an almanac

[C#] Copy Code

// Configure properties 

// Use the scenario's analysis interval 

propagator.EphemerisInterval.SetImplicitInterval(scenario.Vgt.EventIntervals["AnalysisInterval"]); 

 

// PRN must be set before configuring GPS almanac 

propagator.PRN = Int32.Parse((string)propagator.AvailablePRNs.GetValue(0)); 

 

// Turn the Auto-update off 

propagator.AutoUpdateEnabled = false; 

 

// Specify a catalog 

propagator.SpecifyCatalog.Filename = almanacPath; 

 

// Configure the properties specific to the chosen almanac 

switch (propagator.SpecifyCatalog.Properties.Type) 

{ 

    case AgEVeGPSAlmanacType.eGPSAlmanacTypeSEM: 

        { 

            /* configure the SEM almanac */ 

            IAgVeGPSAlmanacPropertiesSEM sem = propagator.SpecifyCatalog.Properties as IAgVeGPSAlmanacPropertiesSEM; 

            sem.ReferenceWeek = AgEGPSReferenceWeek.eGPSReferenceWeek22Aug1999; 

            break; 

        } 

    case AgEVeGPSAlmanacType.eGPSAlmanacTypeSP3: 

        { 

            /* SP3 almanac contains no configurable properties */ 

            IAgVeGPSAlmanacPropertiesSP3 sp3 = propagator.SpecifyCatalog.Properties as IAgVeGPSAlmanacPropertiesSP3; 

            break; 

        } 

    case AgEVeGPSAlmanacType.eGPSAlmanacTypeYUMA: 

        { 

            /* configure the YUMA almanac */ 

            IAgVeGPSAlmanacPropertiesYUMA yuma = propagator.SpecifyCatalog.Properties as IAgVeGPSAlmanacPropertiesYUMA; 

            yuma.ReferenceWeek = AgEGPSReferenceWeek.eGPSReferenceWeek22Aug1999; 

            break; 

        } 

} 

 

// Propagate 

propagator.Propagate();

Configure the GPS propagator with an almanac

[Visual Basic .NET] Copy Code

' Configure properties
' Use the scenario's analysis interval
 propagator.EphemerisInterval.SetImplicitInterval(scenario.Vgt.EventIntervals("AnalysisInterval"))

' PRN must be set before configuring GPS almanac
 propagator.PRN = Int32.Parse(DirectCast(propagator.AvailablePRNs.GetValue(0), String))

' Turn the Auto-update off
 propagator.AutoUpdateEnabled = False

' Specify a catalog
 propagator.SpecifyCatalog.Filename = almanacPath

' Configure the properties specific to the chosen almanac
Select Case propagator.SpecifyCatalog.Properties.Type
     Case AgEVeGPSAlmanacType.eGPSAlmanacTypeSEM
         If True Then
             ' configure the SEM almanac

             Dim sem As IAgVeGPSAlmanacPropertiesSEM = TryCast(propagator.SpecifyCatalog.Properties, IAgVeGPSAlmanacPropertiesSEM)
             sem.ReferenceWeek = AgEGPSReferenceWeek.eGPSReferenceWeek22Aug1999
             Exit Select
         End If
     Case AgEVeGPSAlmanacType.eGPSAlmanacTypeSP3
         If True Then
             ' SP3 almanac contains no configurable properties

             Dim sp3 As IAgVeGPSAlmanacPropertiesSP3 = TryCast(propagator.SpecifyCatalog.Properties, IAgVeGPSAlmanacPropertiesSP3)
             Exit Select
         End If
     Case AgEVeGPSAlmanacType.eGPSAlmanacTypeYUMA
         If True Then
             ' configure the YUMA almanac

             Dim yuma As IAgVeGPSAlmanacPropertiesYUMA = TryCast(propagator.SpecifyCatalog.Properties, IAgVeGPSAlmanacPropertiesYUMA)
             yuma.ReferenceWeek = AgEGPSReferenceWeek.eGPSReferenceWeek22Aug1999
             Exit Select
         End If
End Select

' Propagate
 propagator.Propagate()

Set the satellite to use the GPS propagator

[Visual Basic .NET] Copy Code

' Set propagator to GPS
 satellite.SetPropagatorType(AgEVePropagatorType.ePropagatorGPS)

' Get the GPS propagator
Dim propagator As IAgVePropagatorGPS = TryCast(satellite.Propagator, IAgVePropagatorGPS)

CoClasses that Implement IAgVePropagatorGPS

Name
AgVePropagatorGPS

AGI STK Objects 11	Send comments on this topic.
IAgVePropagatorGPS Interface