Spacecraft.UmbralShadowTimes(Array, Array) Method

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Description

Determines the entry time, exit time, and duration of a Spacecraft's pass through the shadow of a central body. Events are reported for umbral shadow conditions only. If the specified body is a member of the Earth-Moon system, the counterpart not specified will also be considered in shadow evaluation.

The image below shows the three regions of the spacecraft's central body's shadow, umbra, penumbra, and annular. UmbralShadowTimes reports events for the umbral shadow conditions only.

The three regions of the Spacecraft's central 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.UmbralShadowTimes(	Array EventTime,
	Array EventType)

Arguments

EventTime

Description:

The time that the event occurred.

The FF_Preferences.IntervalEventReportingBehavior property controls whether the start of propagation is reported as an event. 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.

EventType
Description:	The type of the event that occurred. Event type == 101 is entry into umbral shadow. Event type == 102 is exit from umbral shadow.

Return Value

Type:

number

Returns the number of elements filled into EventType and EventTime arrays.

Syntax

myVariable1 = mySpacecraft1.UmbralShadowTimes(myArray1, myArray2);