Description | Example | Return Message | Group

AttCov FOMDefine

Define an attitude figure of merit object

Syntax

AttCov <AttFOMObjectPath> FOMDefine {Satisfaction | Limits | Definition} {FOMOption} <Parameters>

Description

The AttCov FOMDefine command allows the user to specify the method by which the quality of attitude coverage is measured for the figure of merit, and to define the satisfaction criteria that will be applied to the figure of merit. A figure of merit allows you to evaluate the quality of attitude coverage with the selected set of assets.

Satisfaction

If Satisfaction is entered then valid values for {FOMOption} <Parameters> are:

If Satisfaction is set to On, the graphics follow the general behavior for satisfaction graphics. If Satisfaction is set to Off, static graphics are covered by at least one asset at some point during the attitude coverage interval and Animation graphics are currently covered by at least one asset.

<Threshold> is the value that must be met if coverage is considered to be satisfied. Valid values for <Threshold> depend on the type of FOM. For example, for an Access Duration FOM the <Threshold> is entered in seconds.

Limits

Set the limits used in computing attitude coverage statistics. Valid values for Limits {Options} <Parameters> are described in the following table.

If entered, the Minimum and/or Maximum <Value> is entered in units appropriate to the FOM type. In general, Time values are entered in seconds, Angle values are entered in degrees, Angle Rate values are entered in degrees per second, Distance values are entered in Connect distance units, Velocity values are entered in Connect distance units per second.

{Options} <Parameters> Description
Use {On | Off} If On, limits the FOM values to a user-defined range for computing statistics. Only the values within the specified Minimum and Maximum limits will contribute to the statistical parameters.
Exclude {On | Off} If On, only FOM values that are outside of the specified Minimum and Maximum limits are used for computing statistics.
Minimum <Value> Enter the minimum limit of the FOM values used for computing statistics. The Minimum <Value> must be less or equal to the Maximum <Value>.
Maximum <Value> Enter the maximum limit of the FOM values used for computing statistics. The Maximum <Value> must be greater or equal to the Minimum <Value>.

Definition

If Definition is entered then the {FOMOption} <Parameters> can be:

{FOMOption} <Parameters> Description
AccessConstraint Constraint <Name> Enter the valid name for the constraint to be measured.

Note: Constraint name must be entered before other parameters can be entered.

Compute {ComputeValue} [<PercentValue>] Valid values for {ComputeValue} are: Minimum, Maximum, Average, PercentBelow, PercentAbove and Sum.

If {ComputeValue} is PercentBelow or PercentAbove then specify <PercentValue> which is between 0.0 and 100.0.

AcrossAssets {Value} Enter the method for applying the constraint across assets. Valid values are: Minimum, Maximum, Average and Sum.
TimeStep <Value> TimeStep <Value> is entered in Connect time units. Valid values are 0.1 through 315576000.0 seconds.
AccessDuration

Compute {ComputeValue} [<PercentValue>]

Valid values for {ComputeValue} are: Minimum, Maximum, Average, StdDev, PercentAbove and Sum.

If {ComputeValue} is PercentAbove then specify <PercentValue> which is between 0.0 and 100.0.

AccessSeparation

MinTime <Value>

MaxTime <Value>

<Value>, in both cases, is entered in Connect time units and must be greater than 0.0.
CoverageTime

Compute {ComputeValue} [<MinNumAssets>]

Valid values for {ComputeValue} are Percent, Total, PerDay, PercentPerDay, MinPercentPerDay, MaxPercentPerDay, PercentPerDayStdDev, MinPerDay, MaxPerDay, PerDayStdDev, PercentTimeAbove and TotalTimeAbove.

If {ComputeValue} is PercentTimeAbove or TotalTimeAbove then specify <MinNumAssets> which is an integer between 0 and 100.

NAsset

Compute {ComputeValue} [<PercentValue>]

Valid values for {ComputeValue} are Minimum, Maximum, Average, StdDev and PercentAbove.

If {ComputeValue} is PercentAbove then specify <PercentValue> which is between 0.0 and 100.0.

NumberOfAccesses Compute {ComputeValue} [<MinTime> <MaxTime>] Valid values for {ComputeValue} are: Total, MinPerDay, MaxPerDay, AvgPerDay, InSpan, and InSpanPerDay.

If {ComputeValue} is InSpan or InSpanPerDay then specify <MinTime> <MaxTime> which are entered in Connect time units and must be greater than 0.0.

NumberOfGaps Compute {ComputeValue} [<MinTime> <MaxTime>] Valid values for {ComputeValue} are Total, MinPerDay, MaxPerDay, AvgPerDay, InSpan, and InSpanPerDay.

If {ComputeValue} is InSpan or InSpanPerDay then specify <MinTime> <MaxTime> which are entered in Connect time units and must be greater than 0.0.

PointAccuracy Compute {ComputeValue} [<PercentValue>] Valid values for {ComputeValue} are Minimum, Maximum, Average, and PercentBelow.

If {ComputeValue} is PercentBelow then specify <PercentValue> which is between 0.0 and 100.0.

Method {MethodValue} [<BestNValue>] Valid values for {MethodValue} are OverDetermined, Best2, Best2Acc, BestN, and BestNAcc.

If {ComputeValue} is BestN or BestNAcc then specify <BestNValue> which is an integer between 2 and 100.

NavType {NavValue} Valid values for {NavValue} are DRMS, CEP, AppXCep, MaxSigma, MinSigma.
TimeStep <Value> <Value> for TimeStep is entered in Connect time units and must be between 1.0 and 3600.0 seconds.
AssetUncertainty <TruncObjectPath> {AssetMethod} <Value>

The Asset specified by <TruncObjectPath> must already be an assigned asset.

Currently the only valid values for {AssetMethod} is Constant.

If {AssetMethod} is Constant, then <Value> is a number greater than 0.

PointDOP Compute {ComputeValue} [<PercentValue>] Valid values for {ComputeValue} are Minimum, Maximum, Average, and PercentBelow.

If {ComputeValue} is PercentBelow then specify <PercentValue> which is between 0.0 and 100.0.

Method {MethodValue} [<BestNValue>] Valid values for {MethodValue} are OverDetermined, Best2, and BestN.

If {ComputeValue} is BestN then specify <BestNValue> which is an integer between 2 and 100.

DOPType {DOPValue} Valid values for {DOPValue} are DRMS, MaxSigma, MinSigma.
TimeStep <Value> <Value> for TimeStep is entered in Connect time units and must be between 1.0 and 3600.0 seconds.
ResponseTime Compute {ComputeValue} [<PercentValue>] Valid values for {ComputeValue} are Minimum, Maximum, Average, PercentBelow, and PercentBelowGapsOnly.

If {ComputeValue} is PercentBelow or PercentBelowGapsOnly then specify <PercentValue>, which is between 0.0 and 100.0.

MinNumAssets <Value> <Value> for MinNumAssets is an integer between 1 and 9999.
RevisitTime Compute {ComputeValue} [<PercentValue>] Valid values for {ComputeValue} are Minimum, Maximum, Average, StdDev, PercentBelow, PercentBelowGapsOnly, and PercentNumBelow.

If {ComputeValue} is PercentBelow, PercentBelowGapsOnly or PercentNumBelow then specify <PercentValue> which is between 0.0 and 100.0.

{MinNumAssets <Value> | EndGaps <EndGapValue>} <Value> for MinNumAssets is an integer between 0 and 9999.

Valid values for <EndGapValue> are Ignore and Include.

Simple N/A Simple Coverage measures whether or not a point is accessible by any of the assigned assets.
TimeAverageGap N/A Time Average Gap measures the average length of the coverage gap found if the time line for grid points is sampled randomly.

Example

To define DRMS of pointing dilution of precision for the best 2 vector measurements:

AttCov */Satellite/AttCovSat/AttitudeCoverage/AttCov/AttitudeFigureOfMerit/AttFOM FOMDefine Definition PointDOP Compute Minimum DOPType DRMS Method Best2 TimeStep 60.0

To define the satisfaction criterion for a figure of merit so that the FOM value is less than or equal to 2:

AttCov */Satellite/AttCovSat/AttitudeCoverage/AttCov/AttitudeFigureOfMerit/AttFOM FOMDefine Satisfaction AtMost 2.0

To set the vector measurement uncertainty for HR-1017 to a constant value of 0.001 degrees:

AttCov */Satellite/AttCovSat/AttitudeCoverage/AttCov/AttitudeFigureOfMerit/AttFOM FOMDefine Definition PointAccuracy AssetUncertainty Star/HR-1017 Constant 0.001

To set the Access constraint to SarCNR, and set AcrossAsset value:

AttCov */Satellite/AttCovSat/AttitudeCoverage/AttCov/AttitudeFigureOfMerit/AttFOM FOMDefine Definition AccessConstraint Constraint SarCNR AcrossAssets Minimum

To define the figure of merit as AccessDuration:

AttCov */Satellite/Satellite1/AttitudeCoverage/AttitudeCoverage1/AttitudeFigureOfMerit/AttitudeFigureOfMerit1 FOMDefine Definition AccessDuration Compute Sum

ReturnMessage

If activated, Connect returns an acknowledgement message.

Group Membership

This command belongs to the following group(s):

Attitude

Attitude Coverage

Coverage

Version

10

STK Programming Interface 11.0.1