VisibilitySegment.Visibility(Variable) Method

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Description

Evaluates the visibility condition configured by the segment and returns true (1) if the observer can see the target and returns false (0) if the observer can not see the target.

 

Timing Precision Mode

This page describes functionality in millisecond timing precision mode. Millisecond timing precision mode is deprecated and will be removed in a future release. We recommend that you migrate your Mission Plans to nanosecond timing precision mode.

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

 

Method Signature

VisibilitySegment.Visibility(

Variable evaluationEpoch)

 

 

Arguments

evaluationEpoch

Description:

The epoch at which to evaluate visibility.

 

 

 

Return Value

Type:

boolean

 

 

Returns true (1) if visibility is available, and false (0) otherwise.

 

Syntax

myVariable1 = myVisibilitySegment1.Visibility(myVariable2);

 

 

Example 1

This example shows how to configure a VisibilitySegment to determine when a Spacecraft can see a GroundStation, and report the visibility.

 

Spacecraft sc;

GroundStation gs;

VisibilitySegment segment1;

 

segment1.SetObserver(sc);

segment1.SetTarget(gs);

 

segment1.AddOccultingBody(Earth, Moon);

 

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

 

 Report sc.EpochText, segment1.Visibility(sc.Epoch);

 

 Step sc;

 

End;

 

 

Output excerpt:

 

sc.EpochText

segment1.Visibility(sc.Epoch)

Jan 01 2020 18:45:00.000000000

Jan 01 2020 18:50:00.000000000

Jan 01 2020 18:55:00.000000000

Jan 01 2020 19:00:00.000000000

Jan 01 2020 19:05:00.000000000

Jan 01 2020 19:10:00.000000000

Jan 01 2020 19:15:00.000000000

   0.000000000

   0.000000000

   1.000000000

   1.000000000

   1.000000000

   0.000000000

   0.000000000

 

 

 

Example 2

This example shows how to configure a VisibilitySegment to determine when a GroundStation can see the Moon, and report the visibility.

 

Spacecraft sc;

GroundStation gs;

VisibilitySegment segment2;

 

segment2.SetObserver(gs);

segment2.SetTarget(Moon);

 

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

 

 Report sc.EpochText, segment2.Visibility(sc.Epoch);

 

 Step sc;

 

End;

 

 

Output excerpt:

 

sc.EpochText

segment1.Visibility(sc.Epoch)

Jan 01 2020 11:55:00.000000000

Jan 01 2020 12:00:00.000000000

Jan 01 2020 12:05:00.000000000

Jan 01 2020 12:10:00.000000000

Jan 01 2020 12:15:00.000000000

Jan 01 2020 12:20:00.000000000

   1.000000000

   1.000000000

   1.000000000

   0.000000000

   0.000000000

   0.000000000

 

 

 

See also

VisibilitySegment Object

Coverage and Contact Analysis Guide

Visibility Calculators Guide