Package org.orekit.estimation.measurements

Class TurnAroundRange

java.lang.Object

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

org.orekit.estimation.measurements.SignalBasedMeasurement<TurnAroundRange>

org.orekit.estimation.measurements.TurnAroundRange

All Implemented Interfaces:

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

public class TurnAroundRange
extends SignalBasedMeasurement<TurnAroundRange>

Class modeling a turn-around range measurement using a primary observer and a secondary observer.

The measurement is considered to be a signal: - Emitted from the primary observer - Reflected on the spacecraft - Reflected on the secondary observer - Reflected on the spacecraft again - Received on the primary observer Its value is the elapsed time between emission and reception divided by 2c were c is the speed of light. The motion of the stations and the spacecraft during the signal flight time are taken into account. The date of the measurement corresponds to the reception on ground of the reflected signal.

Since:

9.0

Author:

Thierry Ceolin, Luc Maisonobe, Maxime Journot

Field Summary

Fields

Modifier and Type	Field	Description
static final String	MEASUREMENT_TYPE	Type of the measurement.

Constructor Summary

Constructors

Constructor	Description
TurnAroundRange(Observer primaryObserver, Observer secondaryObserver, AbsoluteDate date, double turnAroundRange, double sigma, double baseWeight, ObservableSatellite satellite)	Simple constructor.
TurnAroundRange(Observer primaryObserver, Observer secondaryObserver, AbsoluteDate date, double turnAroundRange, double sigma, double baseWeight, SignalTravelTimeModel signalTravelTimeModel, ObservableSatellite satellite)	Constructor.

Method Summary

Modifier and Type	Method	Description
Observer	getPrimaryObserver()	Get the primary observer from which measurement is performed.
GroundStation	getPrimaryStation()	Deprecated. as of 14.0, replaced by getPrimaryObserver()
Observer	getSecondaryObserver()	Get the secondary observer reflecting the signal.
GroundStation	getSecondaryStation()	Deprecated. as of 14.0, replaced by getSecondaryObserver()
protected EstimatedMeasurement<TurnAroundRange>	theoreticalEvaluation(int iteration, int evaluation, SpacecraftState[] states)	Estimate the theoretical value.
protected EstimatedMeasurementBase<TurnAroundRange>	theoreticalEvaluationWithoutDerivatives(int iteration, int evaluation, SpacecraftState[] states)	Estimate the theoretical value without derivatives.

Methods inherited from class org.orekit.estimation.measurements.SignalBasedMeasurement

getSignalTravelTimeModel, isTwoWay

Methods inherited from class org.orekit.estimation.measurements.AbstractMeasurement

addModifier, addParameterDriver, addParametersDrivers, estimate, estimateWithoutDerivatives, getCoordinates, getDate, getMeasurementQuality, getModifiers, getObservedValue, getParameterIndices, getParametersDrivers, getSatellites, isEnabled, setEnabled, setObservedValue

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

Field Details

MEASUREMENT_TYPE

public static final String MEASUREMENT_TYPE

Type of the measurement.

See Also:

• Constant Field Values

Constructor Details

TurnAroundRange

public TurnAroundRange(Observer primaryObserver,
 Observer secondaryObserver,
 AbsoluteDate date,
 double turnAroundRange,
 double sigma,
 double baseWeight,
 ObservableSatellite satellite)

Simple constructor.

Parameters:

primaryObserver - observer from which measurement is performed

secondaryObserver - observer reflecting the signal

date - date of the measurement

turnAroundRange - observed value

sigma - theoretical standard deviation

baseWeight - base weight

satellite - satellite related to this measurement

Since:

9.3

TurnAroundRange

public TurnAroundRange(Observer primaryObserver,
 Observer secondaryObserver,
 AbsoluteDate date,
 double turnAroundRange,
 double sigma,
 double baseWeight,
 SignalTravelTimeModel signalTravelTimeModel,
 ObservableSatellite satellite)

Constructor.

Parameters:

primaryObserver - observer from which measurement is performed

secondaryObserver - observer reflecting the signal

date - date of the measurement

turnAroundRange - observed value

sigma - theoretical standard deviation

baseWeight - base weight

signalTravelTimeModel - signal travel time model

satellite - satellite related to this measurement

Since:

14.0

Method Details

getPrimaryStation

@Deprecated
public GroundStation getPrimaryStation()

Deprecated.

as of 14.0, replaced by getPrimaryObserver()

Get the primary ground station, the one that receives the signal first.

Returns:

primary ground station

getPrimaryObserver

public Observer getPrimaryObserver()

Get the primary observer from which measurement is performed.

Returns:

primary observer from which measurement is performed

getSecondaryStation

@Deprecated
public GroundStation getSecondaryStation()

Deprecated.

as of 14.0, replaced by getSecondaryObserver()

Get the secondary ground station, the one that receives the signal first.

Returns:

secondary ground station

getSecondaryObserver

public Observer getSecondaryObserver()

Get the secondary observer reflecting the signal.

Returns:

secondary observer reflecting the signal

theoreticalEvaluationWithoutDerivatives

protected EstimatedMeasurementBase<TurnAroundRange> 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.

Overrides:

theoreticalEvaluationWithoutDerivatives in class AbstractMeasurement<TurnAroundRange>

Parameters:

iteration - iteration number

evaluation - evaluation number

states - orbital states at measurement date

Returns:

theoretical value

See Also:

• AbstractMeasurement.estimate(int, int, SpacecraftState[])

theoreticalEvaluation

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

Estimate the theoretical value.

The theoretical value does not have any modifiers applied.

Specified by:

theoreticalEvaluation in class AbstractMeasurement<TurnAroundRange>

Parameters:

iteration - iteration number

evaluation - evaluation number

states - orbital states at measurement date

Returns:

theoretical value

See Also:

• AbstractMeasurement.estimate(int, int, SpacecraftState[])