Spacecraft.FOVInterference(Star, Spacecraft, Variable) Method

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Description

Returns the time of entry into an area of interference, the time of exit from the area of interference, and the duration of interference. Interference is defined to be the period when both an object of interest and an interfering object are within the field-of-view of a Spacecraft sensor, and the interfering object lies within a user-specified cone about the Spacecraft to object-of-interest vector.

 

 

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

Spacecraft.FOVInterference(

Star objectOfInterest,

Spacecraft interferenceObject,

Variable coneAngle)

 

 

Arguments

objectOfInterest

Description:

The Star object in which the calling Spacecraft's sensor is interested. An element of a StarField object can be specified, i.e. myStarField[0].

 

 

interferenceObject

Description:

The Spacecraft object that will impose interference on the calling Spacecraft's sensor if it is positioned such that it meets the criteria above.

 

 

coneAngle

Description:

This is the half angle of the cone in degrees for which the interference is determined.

Units:

deg

Valid Range:

-360 ≤ coneAngle ≤ 360

 

 

 

Return Value

Type:

string

 

 

Returns the Calendar time of entry into an area of interference, the time of exit from the area of interference, and the duration of interference.

 

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 = mySpacecraft1.FOVInterference(myStar1, mySpacecraft2, myVariable1);

 

 

Example 1

This example demonstrates how to generate a report of a Spacecraft's field of view interference times. The field of view interference times method reports when the Star of interest and interfering Spacecraft are within the field-of-view of the calling Spacecraft's sensor.

 

Spacecraft Spacecraft1;

Spacecraft Spacecraft2;

StarField StarField1;

 

// Create a Star and add a Sensor to be used by the Spacecraft.FOVInterference() method 

StarField1.Count = 1;

Spacecraft1.AddSensor("Sensor1");

Spacecraft1.Sensors[0].BoresightUnitVector = {0, 0, -1};

 

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

While(Spacecraft1.ElapsedDays < 1);

 

      Report Spacecraft1.FOVInterference(StarField1[0], Spacecraft2, 45 /* Cone Half Angle */) to "SC_FOVInter_SCStar.txt";

      Step Spacecraft1;

      Step Spacecraft2 to (Spacecraft2.Epoch == Spacecraft1.Epoch);

 

End;

 

 Or

 

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

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

 

      Report Spacecraft1.FOVInterference(StarField1[0], Spacecraft2, 45 /* Cone Half Angle */) to "SC_FOVInter_SCStar.txt";

      Step Spacecraft1;

      Step Spacecraft2 to (Spacecraft2.Epoch == Spacecraft1.Epoch);

 

End;

 

 

Output:

 

Note: Output generated using nanosecond timing precision mode.

 

FOVInterference Event        Entry Epoch                      Exit Epoch                          Duration(min)

Sensor1 -->                  Jan 01 2020 01:02:11.616210937   Jan 01 2020 01:18:06.035156250      15.906982422

Sensor1 -->                  Jan 01 2020 02:41:08.115234375   Jan 01 2020 02:57:02.460937500      15.905761719

Sensor1 -->                  Jan 01 2020 04:20:04.541015625   Jan 01 2020 04:35:58.959960937      15.906982422

Sensor1 -->                  Jan 01 2020 05:59:01.040039062   Jan 01 2020 06:14:55.458984375      15.906982422

Sensor1 -->                  Jan 01 2020 07:37:57.612304687   Jan 01 2020 07:53:52.031250000      15.906982422

Sensor1 -->                  Jan 01 2020 09:16:54.184570312   Jan 01 2020 09:32:48.676757812      15.908203125

Sensor1 -->                  Jan 01 2020 10:55:50.756835937   Jan 01 2020 11:11:45.175781250      15.906982422

Sensor1 -->                  Jan 01 2020 12:34:47.255859375   Jan 01 2020 12:50:41.601562500      15.905761719

Sensor1 -->                  Jan 01 2020 14:13:43.681640625   Jan 01 2020 14:29:38.027343750      15.905761719

Sensor1 -->                  Jan 01 2020 15:52:40.107421875   Jan 01 2020 16:08:34.453125000      15.905761719

Sensor1 -->                  Jan 01 2020 17:31:36.533203125   Jan 01 2020 17:47:30.952148437      15.906982422

Sensor1 -->                  Jan 01 2020 19:10:33.032226562   Jan 01 2020 19:26:27.451171875      15.906982422

Sensor1 -->                  Jan 01 2020 20:49:29.604492187   Jan 01 2020 21:05:24.023437500      15.906982422

Sensor1 -->                  Jan 01 2020 22:28:26.176757812   Jan 01 2020 22:44:20.522460937      15.905761719

 

 

 

See also

Spacecraft Object

Spacecraft.FOVInterference

Spacecraft Propagation Guide

Coverage and Contact Analysis Guide