Spacecraft.ContactTimes(GroundStation, TimeSpanArray, Array) Method

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Description

Contact is determined when the line of sight is within the contactGroundStation masking.

 

The ContactTimes method will account for refraction if refraction modeling is turned on using the GroundStation.RefractionModelType property.

 

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.ContactTimes(

GroundStation contactGroundStation,

TimeSpanArray EventTime,

Array EventType)

 

 

Arguments

contactGroundStation

Description:

GroundStation to use in contact calculation.

 

 

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 contact starts before the beginning of the propagation span, FreeFlyer will label the start of the propagation as the start of contact.

 

 

EventType

Description:

The type of the event that occurred. Event Type == 1 is entry into Contact. Event Type == 2 is exit from Contact.

 

 

 

Return Value

Type:

number

 

 

Returns the number of elements filled into EventType and EventTime arrays

 

Syntax

myVariable1 = mySpacecraft1.ContactTimes(myGroundStation1, myTimeSpanArray1, myArray1);

 

 

Example 1

This example demonstrates how to generate a report of a Spacecraft's contact times with a GroundStation.

 

Spacecraft Spacecraft1;

GroundStation GroundStation1;

 

Variable i;

Variable numEvents;

TimeSpanArray EventTime;

Array EventType;

String gsEventType;

String gsEventTime;

DataTableWindow GSReport({gsEventType, gsEventTime});

 

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

 

          numEvents = Spacecraft1.ContactTimes(GroundStation1, EventTime, EventType);

 

          If(numEvents > 0) then;

                      For i = 0 to numEvents - 1 step 1;

                                  Switch (EventType[i]);

                                              Case 1:

                                                          gsEventType = "Entry into Contact: ";

                                                          gsEventTime = EventTime[i].ConvertToCalendarDate();

                                                          Update GSReport;

                                                          Break;

                                              Case 2:

                                                          gsEventType = "Exit from Contact: ";

                                                          gsEventTime = EventTime[i].ConvertToCalendarDate();

                                                          Update GSReport;

                                  End;

                      End;

          End;

 

          Step Spacecraft1;

 

End;

 

 

Output:

 

gsEventType

gsEventTime

Entry into Contact:

Exit from Contact:

Entry into Contact:

Exit from Contact:

Entry into Contact:

Exit from Contact:

Entry into Contact:

Exit from Contact:

Jan 01 2020 06:19:55.825195312

Jan 01 2020 06:27:47.944335937

Jan 01 2020 07:57:38.129882812

Jan 01 2020 08:05:20.727539062

Jan 01 2020 17:21:38.144531250

Jan 01 2020 17:27:06.269531250

Jan 01 2020 18:57:14.692382812

Jan 01 2020 19:06:15.878906250

 

 

 

See also

Spacecraft Object

Spacecraft.ContactTimes

Spacecraft Propagation Guide

Coverage and Contact Analysis Guide