Spacecraft.ShadowTimes(Variable, TimeSpanArray, Array) Method

Top

Description

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

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.ShadowTimes(	Variable celestialObjectID,
	TimeSpanArray EventTime,
	Array EventType)

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.

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. Event type == 101 is entry into umbral shadow. Event type == 102 is exit from umbral shadow. Event type == 201 is entry into penumbral shadow. Event type == 202 is exit from penumbral shadow.

Return Value

Type:

number

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

Syntax

myVariable1 = mySpacecraft1.ShadowTimes(myVariable2, myTimeSpanArray1, myArray1);

This example demonstrates how to generate a report of a Spacecraft's passes into a CelestialObject's shadow. An event type == 1 is entry into the annular shadow, type == 2 is an exit from the annular shadow, type == 101 is entry into umbral shadow, type == 102 is exit from the umbral shadow, type == 201 is entry into penumbral shadow and type == 202 is exit from the penumbral shadow.

Spacecraft Spacecraft1;

Variable i;

Variable shadowTimes;

TimeSpanArray EventTime;

Array EventType;

String scEventType;

String scEventTime;

DataTableWindow SCReport({scEventType, scEventTime});

// This example sets the central body to Mars and includes it in the

// Spacecraft's Force Model.

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

shadowTimes = Spacecraft1.ShadowTimes(4 /* Body ID for Mars */, EventTime, EventType);

If (shadowTimes > 0) then;

For i = 0 to shadowTimes - 1 step 1;

Switch (EventType[i]);

Case 1:

scEventType = "Entry into Annular Shadow: ";

scEventTime = EventTime[i].ConvertToCalendarDate();

Update SCReport;

Break;

Case 2:

scEventType = "Exit from Anunlar Shadow: ";

scEventTime = EventTime[i].ConvertToCalendarDate();

Update SCReport;

Break;

Case 101:

scEventType = "Entry into Umbral Shadow: ";

scEventTime = EventTime[i].ConvertToCalendarDate();

Update SCReport;

Break;

Case 102:

scEventType = "Exit from Umbral Shadow: ";

scEventTime = EventTime[i].ConvertToCalendarDate();

Update SCReport;

Break;

Case 201:

scEventType = "Entry into Penumbral Shadow: ";

scEventTime = EventTime[i].ConvertToCalendarDate();

Update SCReport;

Break;

Case 202:

scEventType = "Exit from Penumbral Shadow: ";

scEventTime = EventTime[i].ConvertToCalendarDate();

Update SCReport;

End;

End;

End;

Step Spacecraft1;

End;

Output:

scEventType

scEventTime

Entry into Penumbral Shadow:

Entry into Umbral Shadow:

Exit from Umbral Shadow:

Exit from Penumbral Shadow:

Entry into Penumbral Shadow:

Entry into Umbral Shadow:

Exit from Umbral Shadow:

Exit from Penumbral Shadow:

Entry into Penumbral Shadow:

Entry into Umbral Shadow:

Exit from Umbral Shadow:

Exit from Penumbral Shadow:

Entry into Penumbral Shadow:

Entry into Umbral Shadow:

Exit from Umbral Shadow:

Exit from Penumbral Shadow:

Entry into Penumbral Shadow:

Entry into Umbral Shadow:

Exit from Umbral Shadow:

Exit from Penumbral Shadow:

Entry into Penumbral Shadow:

Entry into Umbral Shadow:

Exit from Umbral Shadow:

Exit from Penumbral Shadow:

Entry into Penumbral Shadow:

Entry into Umbral Shadow:

Exit from Umbral Shadow:

Exit from Penumbral Shadow:

Entry into Penumbral Shadow:

Entry into Umbral Shadow:

Exit from Umbral Shadow:

Exit from Penumbral Shadow:

Entry into Penumbral Shadow:

Entry into Umbral Shadow:

Exit from Umbral Shadow:

Exit from Penumbral Shadow:

Entry into Penumbral Shadow:

Entry into Umbral Shadow:

Jan 01 2020 00:12:12.202148437

Jan 01 2020 00:12:21.284179687

Jan 01 2020 00:52:49.628906250

Jan 01 2020 00:52:58.784179687

Jan 01 2020 02:48:33.574218750

Jan 01 2020 02:48:42.729492187

Jan 01 2020 03:29:10.781250000

Jan 01 2020 03:29:19.936523437

Jan 01 2020 05:24:54.946289062

Jan 01 2020 05:25:04.101562500

Jan 01 2020 06:05:32.006835937

Jan 01 2020 06:05:41.088867187

Jan 01 2020 08:01:16.318359375

Jan 01 2020 08:01:25.473632812

Jan 01 2020 08:41:53.159179687

Jan 01 2020 08:42:02.314453125

Jan 01 2020 10:37:37.690429687

Jan 01 2020 10:37:46.845703125

Jan 01 2020 11:18:14.311523437

Jan 01 2020 11:18:23.466796875

Jan 01 2020 13:13:59.062500000

Jan 01 2020 13:14:08.217773437

Jan 01 2020 13:54:35.537109375

Jan 01 2020 13:54:44.619140625

Jan 01 2020 15:50:20.507812500

Jan 01 2020 15:50:29.589843750

Jan 01 2020 16:30:56.689453125

Jan 01 2020 16:31:05.844726562

Jan 01 2020 18:26:41.879882812

Jan 01 2020 18:26:51.035156250

Jan 01 2020 19:07:17.841796875

Jan 01 2020 19:07:26.997070312

Jan 01 2020 21:03:03.251953125

Jan 01 2020 21:03:12.407226562

Jan 01 2020 21:43:39.067382812

Jan 01 2020 21:43:48.222656250

Jan 01 2020 23:39:24.624023437

Jan 01 2020 23:39:33.779296875

See also

Spacecraft Object

Spacecraft.ShadowTimes

Spacecraft Propagation Guide

Coverage and Contact Analysis Guide