PointGroup.Coverage(Formation, Array, Array, Array) Method

Description

This method provides sensor coverage analysis for the set of points defined by a PointGroup. This can be used to determine what parts of the central body can be seen by a given sensor at some point in time, using the current epoch of the specified Spacecraft or Formation. The coverage analysis can be extended over a period of time by calling this method inside a propagation loop. The active Sensors on each Spacecraft will be used to determine coverage.

Array output arguments are used to capture the statistics of the coverage analysis. Do not use these arrays as output arguments for more than one method. Note that the dimensions of the argument arrays are set when the Coverage method is first called; the dimension is not reset by subsequent calls. The Coverage method returns a flag indicating whether the coverage has changed since the last method call. This can be used to increase performance by indicating that further analysis is not necessary if the coverage statistics have not changed.

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 method has a state. See the Methods and Properties with State page for more information.

Method Signature

PointGroup.Coverage(	Formation formation,
	Array coverageArray,
	Array revisitArray,
	Array inviewArray)

Arguments

formation
Description:	Formation containing Spacecraft whose Sensors will be used for the coverage analysis.

coverageArray
Description:	This array holds the coverage for the entire set of Sensors. A zero indicates the point has never been in view of any Sensor of the set. A one indicates the point has been in view of at least one Sensor of the set.

revisitArray

Description:

This array contains seven statistics of the revisits of the points. A visit is defined as an interval in which a point is continually in view of any single Sensor. A revisit is the reoccurrence of a visit with the revisit time as the time elapsed between the beginning of subsequent visits. The revisit time is reported in units of days. Points are numbered from 0 to ( PointGroup.NumberOfPoints - 1 ). All values contained in this array will have Nanosecond precision.

Statistic #1 - number of times a point has had visits. The array index for point number M is ( pointNumber ).

Statistic #2 - average time between visits. The array index for a point is ( 1 x PointGroup.NumberOfPoints + pointNumber ).

Statistic #3 - last revisit time. The array index for a point is ( 2 x PointGroup.NumberOfPoints + pointNumber ).

Statistic #4 - epoch of the beginning of the last visit. The array index for a point is ( 3 x PointGroup.NumberOfPoints + pointNumber ).

Statistic #5 - maximum time between visits. The array index for a point is ( 4 x PointGroup.NumberOfPoints + pointNumber ).

Statistic #6 - minimum time between visits. The array index for a point is ( 5 x PointGroup.NumberOfPoints + pointNumber ).

Statistic #7 - sum of the square of the time between visits. The array index for a point is ( 6 x PointGroup.NumberOfPoints + pointNumber ).

inviewArray

Description:

This array tracks the number of times that the InView evaluation has been performed for each individual Sensor. The array is only updated when a Sensor is in view of a point. Sensors are numbered from zero upward matching the order in which the Spacecraft are included in the argument list of the Coverage method and then the order in which they are attached to individual Spacecraft. Points are numbered from 0 to ( PointGroup.NumberOfPoints - 1 ). A point for a particular sensor is then: ( SensorNumber * PointGroup.NumberOfPoints ) + pointNumber.

Return Value

Type:

number

Returns a 1 if the coverage has changed since the last method call, and a 0 if coverage has not changed.

Syntax

myVariable1 = myPointGroup1.Coverage(myFormation1, myArray1, myArray2, myArray3);