Package org.orekit.estimation.measurements

Class AbstractMeasurement<T extends ObservedMeasurement<T>>

java.lang.Object

org.orekit.estimation.measurements.AbstractMeasurement<T>

Type Parameters:

T - the type of the measurement

All Implemented Interfaces:

Comparable<ComparableMeasurement>, ComparableMeasurement, ObservedMeasurement<T>, TimeStamped, ParameterDriversProvider

Direct Known Subclasses:

MultiplexedMeasurement, PseudoMeasurement, SignalBasedMeasurement

public abstract class AbstractMeasurement<T extends ObservedMeasurement<T>>
extends Object
implements ObservedMeasurement<T>

Abstract class handling measurements boilerplate.

Since:

8.0

Author:

Luc Maisonobe

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractMeasurement(AbsoluteDate date, double[] observed, double[] sigma, double[] baseWeight, List<ObservableSatellite> satellites)	Simple constructor, for multi-dimensional measurements.
protected	AbstractMeasurement(AbsoluteDate date, double[] observed, MeasurementQuality measurementQuality, List<ObservableSatellite> satellites)	Simple constructor, for multi-dimensional measurements.
protected	AbstractMeasurement(AbsoluteDate date, double observed, double sigma, double baseWeight, List<ObservableSatellite> satellites)	Simple constructor for mono-dimensional measurements.

Method Summary

Modifier and Type	Method	Description
void	addModifier(EstimationModifier<T> modifier)	Add a modifier.
protected void	addParameterDriver(ParameterDriver driver)	Add a parameter driver.
protected void	addParametersDrivers(List<ParameterDriver> drivers)	Add a list of parameter drivers all at once.
EstimatedMeasurement<T>	estimate(int iteration, int evaluation, SpacecraftState[] states)	Estimate the theoretical value of the measurement, with derivatives.
EstimatedMeasurementBase<T>	estimateWithoutDerivatives(int iteration, int evaluation, SpacecraftState[] states)	Estimate the theoretical value of the measurement, without derivatives.
static TimeStampedFieldPVCoordinates<Gradient>	getCoordinates(SpacecraftState state, int firstDerivative, int freeParameters)	Get Cartesian coordinates as derivatives.
AbsoluteDate	getDate()	Get the date.
MeasurementQuality	getMeasurementQuality()	Getter for the measurement quality data as used in estimation.
List<EstimationModifier<T>>	getModifiers()	Get the modifiers that apply to a measurement.
double[]	getObservedValue()	Get the observed value.
protected Map<String,Integer>	getParameterIndices(SpacecraftState[] states)	Form the mapping between parameters' names and derivatives' indices.
List<ParameterDriver>	getParametersDrivers()	Get the drivers for parameters.
List<ObservableSatellite>	getSatellites()	Get the satellites related to this measurement.
boolean	isEnabled()	Check if a measurement is enabled.
final void	setEnabled(boolean enabled)	Enable or disable a measurement.
void	setObservedValue(double[] newObserved)	Set the observed value.
protected abstract EstimatedMeasurement<T>	theoreticalEvaluation(int iteration, int evaluation, SpacecraftState[] states)	Estimate the theoretical value.
protected EstimatedMeasurementBase<T>	theoreticalEvaluationWithoutDerivatives(int iteration, int evaluation, SpacecraftState[] states)	Estimate the theoretical value without derivatives.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.orekit.estimation.measurements.ComparableMeasurement

compareTo

Methods inherited from interface org.orekit.estimation.measurements.ObservedMeasurement

estimateWithoutDerivatives, getBaseWeight, getDimension, getMeasurementType, getTheoreticalStandardDeviation

Methods inherited from interface org.orekit.utils.ParameterDriversProvider

getNbParametersDriversValue, getParameterDriver, getParameters, getParameters, getParameters, getParameters, getParametersAllValues, getParametersAllValues, isSupported

Methods inherited from interface org.orekit.time.TimeStamped

durationFrom

Constructor Details

AbstractMeasurement

protected AbstractMeasurement(AbsoluteDate date,
 double observed,
 double sigma,
 double baseWeight,
 List<ObservableSatellite> satellites)

Simple constructor for mono-dimensional measurements.

At construction, a measurement is enabled.

Parameters:

date - date of the measurement

observed - observed value

sigma - theoretical standard deviation

baseWeight - base weight

satellites - satellites related to this measurement

Since:

14.0

AbstractMeasurement

protected AbstractMeasurement(AbsoluteDate date,
 double[] observed,
 double[] sigma,
 double[] baseWeight,
 List<ObservableSatellite> satellites)

Simple constructor, for multi-dimensional measurements.

At construction, a measurement is enabled.

Parameters:

date - date of the measurement

observed - observed value

sigma - theoretical standard deviation

baseWeight - base weight

satellites - satellites related to this measurement

Since:

14.0

AbstractMeasurement

protected AbstractMeasurement(AbsoluteDate date,
 double[] observed,
 MeasurementQuality measurementQuality,
 List<ObservableSatellite> satellites)

Simple constructor, for multi-dimensional measurements.

At construction, a measurement is enabled.

Parameters:

date - date of the measurement

observed - observed value

measurementQuality - measurement quality data

satellites - satellites related to this measurement

Since:

14.0

Method Details

setObservedValue

public void setObservedValue(double[] newObserved)

Set the observed value.

The observed value is the value that was measured by the instrument.

Specified by:

setObservedValue in interface ComparableMeasurement

Parameters:

newObserved - observed value

addParameterDriver

protected void addParameterDriver(ParameterDriver driver)

Add a parameter driver.

Parameters:

driver - parameter driver to add

Since:

9.3

addParametersDrivers

protected void addParametersDrivers(List<ParameterDriver> drivers)

Add a list of parameter drivers all at once.

Parameters:

drivers - list of parameter drivers to add

Since:

14.0

getParametersDrivers

public List<ParameterDriver> getParametersDrivers()

Get the drivers for parameters.

Specified by:

getParametersDrivers in interface ParameterDriversProvider

Returns:

drivers for parameters

setEnabled

public final void setEnabled(boolean enabled)

Enable or disable a measurement.

Disabling a measurement allow to not consider it at one stage of the orbit determination (for example when it appears to be an outlier as per current estimated covariance).

Specified by:

setEnabled in interface ObservedMeasurement<T extends ObservedMeasurement<T>>

Parameters:

enabled - if true the measurement will be enabled, otherwise it will be disabled

isEnabled

public boolean isEnabled()

Check if a measurement is enabled.

Specified by:

isEnabled in interface ObservedMeasurement<T extends ObservedMeasurement<T>>

Returns:

true if the measurement is enabled

getMeasurementQuality

public MeasurementQuality getMeasurementQuality()

Getter for the measurement quality data as used in estimation. Note that in Orekit the crossed-terms of the covariance matrix are only used by Kalman filters, not least squares.

Specified by:

getMeasurementQuality in interface ObservedMeasurement<T extends ObservedMeasurement<T>>

Returns:

measurement quality

getSatellites

public List<ObservableSatellite> getSatellites()

Get the satellites related to this measurement.

Specified by:

getSatellites in interface ObservedMeasurement<T extends ObservedMeasurement<T>>

Returns:

satellites related to this measurement

theoreticalEvaluationWithoutDerivatives

protected EstimatedMeasurementBase<T> theoreticalEvaluationWithoutDerivatives(int iteration,
 int evaluation,
 SpacecraftState[] states)

Estimate the theoretical value without derivatives. The default implementation uses the computation with derivatives and ought to be overwritten for performance.

The theoretical value does not have any modifiers applied.

Parameters:

iteration - iteration number

evaluation - evaluation number

states - orbital states at measurement date

Returns:

theoretical value

Since:

12.0

See Also:

• estimate(int, int, SpacecraftState[])

theoreticalEvaluation

protected abstract EstimatedMeasurement<T> theoreticalEvaluation(int iteration,
 int evaluation,
 SpacecraftState[] states)

Estimate the theoretical value.

The theoretical value does not have any modifiers applied.

Parameters:

iteration - iteration number

evaluation - evaluation number

states - orbital states at measurement date

Returns:

theoretical value

See Also:

• estimate(int, int, SpacecraftState[])

estimateWithoutDerivatives

public EstimatedMeasurementBase<T> estimateWithoutDerivatives(int iteration,
 int evaluation,
 SpacecraftState[] states)

Estimate the theoretical value of the measurement, without derivatives. For use in orbit determination.

The estimated value is the combination of the raw estimated value and all the modifiers that apply to the measurement.

Specified by:

estimateWithoutDerivatives in interface ObservedMeasurement<T extends ObservedMeasurement<T>>

Parameters:

iteration - iteration number

evaluation - evaluations number

states - orbital states corresponding to ObservedMeasurement.getSatellites() at measurement date

Returns:

estimated measurement

estimate

public EstimatedMeasurement<T> estimate(int iteration,
 int evaluation,
 SpacecraftState[] states)

Estimate the theoretical value of the measurement, with derivatives.

The estimated value is the combination of the raw estimated value and all the modifiers that apply to the measurement.

Specified by:

estimate in interface ObservedMeasurement<T extends ObservedMeasurement<T>>

Parameters:

iteration - iteration number

evaluation - evaluations number

states - orbital states corresponding to ObservedMeasurement.getSatellites() at measurement date

Returns:

estimated measurement

getDate

public AbsoluteDate getDate()

Get the date.

Specified by:

getDate in interface TimeStamped

Returns:

date attached to the object

getObservedValue

public double[] getObservedValue()

Get the observed value.

The observed value is the value that was measured by the instrument.

Specified by:

getObservedValue in interface ComparableMeasurement

Returns:

observed value

addModifier

public void addModifier(EstimationModifier<T> modifier)

Add a modifier.

The modifiers are applied in the order in which they are added in order to estimate the measurement.

Specified by:

addModifier in interface ObservedMeasurement<T extends ObservedMeasurement<T>>

Parameters:

modifier - modifier to add

See Also:

• ObservedMeasurement.getModifiers()

getModifiers

public List<EstimationModifier<T>> getModifiers()

Get the modifiers that apply to a measurement.

Specified by:

getModifiers in interface ObservedMeasurement<T extends ObservedMeasurement<T>>

Returns:

modifiers that apply to a measurement

See Also:

• ObservedMeasurement.addModifier(EstimationModifier)

getCoordinates

public static TimeStampedFieldPVCoordinates<Gradient> getCoordinates(SpacecraftState state,
 int firstDerivative,
 int freeParameters)

Get Cartesian coordinates as derivatives.

The position will correspond to variables firstDerivative, firstDerivative + 1 and firstDerivative + 2. The velocity will correspond to variables firstDerivative + 3, firstDerivative + 4 and firstDerivative + 5. The acceleration will correspond to constants.

Parameters:

state - state of the satellite considered

firstDerivative - index of the first derivative

freeParameters - total number of free parameters in the gradient

Returns:

Cartesian coordinates as derivatives

Since:

10.2

getParameterIndices

protected Map<String,Integer> getParameterIndices(SpacecraftState[] states)

Form the mapping between parameters' names and derivatives' indices.

Parameters:

states - observables

Returns:

map

Since:

14.0