Spacecraft.ShadowTimes(Variable) Method

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Description

Determines the entry time, exit time, and duration of a Spacecraft's pass through the shadow of a CelestialObject specified by celestialObjectID.

 

The shadow times are determined using a conical shadow. The algorithm to determine the times a Spacecraft is in any portion of the occulting body is shown in the diagram below.

 

Algorithm used to determine if a Spacecraft is in the occulting body's shadow.

Algorithm used to determine if a Spacecraft is in the occulting body's shadow.

 

Note: This method uses a spherical model for the occulting body. Use the options available in the VisibilityCalculator to exercise more control over the analysis.

 

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.

 

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.ShadowTimes(

Variable celestialObjectID)

 

 

Arguments

celestialObjectID

Description:

ID of the CelestialObject to use as the occulting body. Body ID's 1-11 are assigned to the default Solar System objects, as shown below. Custom CelestialObjects will have body ID's starting at 12 and assigned in the order they are created.

Valid Values:

Celestial Object

Value

Mercury

Mercury.BodyID or 1

Venus

Venus.BodyID or 2

Earth

Earth.BodyID or 3

Mars

Mars.BodyID or 4

Jupiter

Jupiter.BodyID or 5

Saturn

Saturn.BodyID or 6

Uranus

Uranus.BodyID or 7

Neptune

Neptune.BodyID or 8

Pluto

Pluto.BodyID or 9

Moon

Moon.BodyID or 10

Sun

Sun.BodyID or 11

<Custom CelestialBody>

<Custom CelestialBody>.BodyID, starting at 12 and assigned in the order the custom CelestialObjects are created.

 

 

 

 

Return Value

Type:

string

 

 

Returns a string containing the entry time, exit time, and duration of any passes through the shadow of the specified central body.

 

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

 

Syntax

myString1 = mySpacecraft1.ShadowTimes(myVariable1);

 

 

See also

Spacecraft Object

Spacecraft.ShadowTimes

Spacecraft Propagation Guide

Coverage and Contact Analysis Guide