GroundStation.TrackingInterference(Spacecraft, Variable, Star) Method

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Description

Returns a formatted string which can be reported to an output file using the Report command. For each interference period, the report will include the start time, end time, and duration of the interference between the GroundStation and the trackedSpacecraft due to interferingStar.

 

FreeFlyer calculates interference based on the times when the center of the interfering object is within the cone. If you want to model a non-zero angular width for an interfering object, you can add half the angular width of that object (as seen from the GroundStation) to the desired interference half-angle to get the total cone half-angle.

 

Note: When more than one interfering object is specified, ALL of these objects (as opposed to ANY) must lie within the interference cone for the tracking to be considered interfered.

 

The TrackingInterference method will account for refraction if refraction modeling is turned on using the GroundStation.RefractionModelType property.

 

 

Timing Precision Mode

This page describes functionality in nanosecond timing precision mode.

Click here to see the documentation for this object in millisecond timing precision mode.

 

Note: This is an interval method. See the Interval Methods page for more information.

Note: This method has a state. See the Methods and Properties with State page for more information.

 

Method Signature

GroundStation.TrackingInterference(

Spacecraft trackedSpacecraft,

Variable interferenceAngle,

Star interferingStar)

 

 

Arguments

trackedSpacecraft

Description:

The Spacecraft to be tracked by the GroundStation.

 

 

interferenceAngle

Description:

The cone half angle about the GroundStation-to-Spacecraft vector used to determine interference.

Units:

deg

Valid Range:

-360 ≤ interferenceAngle ≤ 360

 

 

interferingStar

Description:

The interfering Star(s).

 

 

 

Return Value

Type:

string

 

 

Returns a formatted string which includes the start time, end time, and duration when a GroundStation tracking a Spacecraft is interfered with by a Star, Celestial Object, or another Spacecraft.

 

The FF_Preferences.IntervalEventReportingBehavior property controls whether the start and end of propagation are reported as events. By default, if the interference starts before the beginning of the propagation span, FreeFlyer will label the start of the propagation as the start of the interference. If the interference extends past the end of the propagation span, FreeFlyer labels the end of propagation as the end of the interference.

 

Syntax

myString1 = myGroundStation1.TrackingInterference(mySpacecraft1, myVariable1, myStar1);

 

 

Example 1

This example demonstrates how to generate a report of a GroundStation's tracking interference with a Star.

 

Spacecraft Spacecraft1;

GroundStation GroundStation1;

StarField StarField1;

 

// Create Star to be used with the GroundStation.TrackingInterference() method

StarField1.Count = 1;

 

// *** For Millisecond Mode Only ***

While (Spacecraft1.ElapsedDays < 1);

 

          Report GroundStation1.TrackingInterference(Spacecraft1, 50 /* Interference Angle */, StarField1[0]) to "GS_TrackingInterf_Star.txt";

          Step Spacecraft1;

 

End;

 

Or

 

// *** For Nanosecond Mode Only ***

While (Spacecraft1.ElapsedTime < TIMESPAN(1 days));

 

          Report GroundStation1.TrackingInterference(Spacecraft1, 50 /* Interference Angle */, StarField1[0]) to "GS_TrackingInterf_Star.txt";

          Step Spacecraft1;

 

End;

 

 

Output:

 

Note: Output generated using nanosecond timing precision mode.

 

TrackingInterference Event                       Entry Epoch                                             Exit Epoch                                                    Duration(min)

GroundStation1 --> Spacecraft1   Jan 01 2020 06:19:55.825195312  Jan 01 2020 06:21:11.557617187    1.262207031

GroundStation1 --> Spacecraft1   Jan 01 2020 07:57:38.129882812  Jan 01 2020 08:00:45.996093750    3.131103516

GroundStation1 --> Spacecraft1   Jan 01 2020 17:25:29.809570312  Jan 01 2020 17:27:06.269531250    1.607666016

GroundStation1 --> Spacecraft1   Jan 01 2020 19:03:06.914062500  Jan 01 2020 19:06:15.878906250    3.149414063

 

 

 

See also

GroundStation Object

GroundStation.TrackingInterference

Coverage and Contact Analysis Guide

GroundStations Guide