Spacecraft.PassData(GroundStation, TimeSpanArray, Array, Array) Method

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Description

Returns the number of elements that have been populated into the EventTime, EventType, and EventElevation arrays. The arrays are populated with the time, type, and elevation of pass events, where an event can be: Acquisition of Signal (AOS), Loss of Signal (LOS), and the maximum elevation of the contact.

 

The PassData 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.PassData(

GroundStation groundStation,

TimeSpanArray EventTime,

Array EventType,

Array EventElevation)

 

 

Arguments

groundStation

Description:

The GroundStation to be used in the 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 the pass starts before the beginning of the propagation span, FreeFlyer will label the start of the propagation as the start of the pass.

 

 

EventType

Description:

The type of the event that occurred. Event Type == 1 is beginning of pass. Event Type == 2 is end of pass. Event Type == 3 is maximum elevation of pass.

 

 

EventElevation

Description:

The elevation when the event occurred.

 

 

 

Return Value

Type:

number

 

 

Returns the number of elements filled into the EventTime, EventType, and EventElevation arrays

 

Syntax

myVariable1 = mySpacecraft1.PassData(myGroundStation1, myTimeSpanArray1, myArray1, myArray2);

 

 

Example 1

This example demonstrates how to generate a report of a Spacecraft's passes over a GroundStation. An EventType == 1 is Acquisition of Signal (AOS), EventType == 2 is Loss of Signal (LOS) and EventType == 3 is the maximum elevation of contact.

 

Spacecraft Spacecraft1;

GroundStation GroundStation1;

 

Variable i;

Variable PassDataElements;

Variable scEventElevation;

TimeSpanArray EventTime;

Array EventType;

Array EventElevation;

String scEventType;

String scEventTime;

DataTableWindow SCReport({scEventType, scEventTime, scEventElevation});

 

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

 

          PassDataElements = Spacecraft1.PassData(GroundStation1,EventTime,EventType,EventElevation);

 

          If (PassDataElements > 0) then;

                      For i = 0 to PassDataElements - 1 step 1;

                                  Switch (EventType[i]);

                                              Case 1:

                                                          scEventType = "Spacecraft AOS: ";

                                                          scEventTime = EventTime[i].ConvertToCalendarDate();

                                                          scEventElevation = EventElevation[i];

                                                          Update SCReport;

                                                          Break;

                                              Case 2:

                                                          scEventType = "Spacecraft LOS: ";

                                                          scEventTime = EventTime[i].ConvertToCalendarDate();

                                                          scEventElevation = EventElevation[i];

                                                          Update SCReport;

                                                          Break;

                                              Case 3:

                                                          scEventType = "Spacecraft Max Elevation: ";

                                                          scEventTime = EventTime[i].ConvertToCalendarDate();

                                                          scEventElevation = EventElevation[i];

                                                          Update SCReport;

                                  End;

                      End;

          End;

 

          Step Spacecraft1;

 

End;

 

 

Output:

 

scEventType

scEventTime

scEventElevation

Spacecraft AOS:

Spacecraft Max Elevation:

Spacecraft LOS:

Spacecraft AOS:

Spacecraft Max Elevation:

Spacecraft LOS:

Spacecraft AOS:

Spacecraft Max Elevation:

Spacecraft LOS:

Spacecraft AOS:

Spacecraft Max Elevation:

Spacecraft LOS:

Jan 01 2020 06:19:55.825195312

Jan 01 2020 06:23:53.728981019

Jan 01 2020 06:27:47.944335937

Jan 01 2020 07:57:38.129882812

Jan 01 2020 08:01:29.428710937

Jan 01 2020 08:05:20.727539062

Jan 01 2020 17:21:38.144531250

Jan 01 2020 17:24:22.207031250

Jan 01 2020 17:27:06.269531250

Jan 01 2020 18:57:14.692382812

Jan 01 2020 19:01:44.228639601

Jan 01 2020 19:06:15.878906250

  10.002930354

  25.199339368

   9.996675481

  10.003544071

  24.687582536

   9.997765982

  10.002939020

  15.336768326

   9.999207434

  10.002042272

  41.560382983

   9.995710430

 

 

 

See also

Spacecraft Object

Spacecraft.PassData

Spacecraft Propagation Guide

Coverage and Contact Analysis Guide