Spacecraft.AnnularShadowTimes(CelestialObject, Array, Array) Method

Determines the entry time, exit time, and duration of a Spacecraft's pass through the shadow of a central body. Events are reported for annular 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 shadow times are determined using a conical shadow. The three regions of the Spacecraft's central body's shadow, umbra, penumbra, and annular, are shown in the diagram below. AnnularShadowTimes reports events when the Spacecraft is in the annual portion of it'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.

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.

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

Method Signature

Spacecraft.AnnularShadowTimes(	CelestialObject celestialObject,
	Array EventTime,
	Array EventType)

Arguments

celestialObject
Description:	CelestialObject to use as the occulting body

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 == 1 is entry into annular shadow. Event type == 2 is exit from annular shadow.

Return Value

Syntax

myVariable1 = mySpacecraft1.AnnularShadowTimes(myCelestialObject1, myArray1, myArray2);