Package org.orekit.estimation.measurements

Class BistaticRangeRate

java.lang.Object

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

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

org.orekit.estimation.measurements.BistaticRangeRelatedMeasurement<BistaticRangeRate>

org.orekit.estimation.measurements.BistaticRangeRate

All Implemented Interfaces:

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

public class BistaticRangeRate
extends BistaticRangeRelatedMeasurement<BistaticRangeRate>

Class modeling a bistatic range rate measurement using an emitter ground station and a receiver ground station.

The measurement is considered to be a signal:

• Emitted from the emitter ground station
• Reflected on the spacecraft
• Received on the receiver ground station

The date of the measurement corresponds to the reception on ground of the reflected signal. The quantity measured at the receiver is the bistatic radial velocity as the sum of the radial velocities with respect to the two stations.

The motion of the stations and the spacecraft during the signal flight time are taken into account.

The Doppler measurement can be obtained by multiplying the velocity by (fe/c), where fe is the emission frequency.

Since:

11.2

Author:

Pascal Parraud

Field Summary

Fields

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

Constructor Summary

Constructors

Constructor	Description
BistaticRangeRate(Observer emitter, Observer receiver, AbsoluteDate date, double rangeRate, double sigma, double baseWeight, ObservableSatellite satellite)	Simple constructor.
BistaticRangeRate(Observer emitter, Observer receiver, AbsoluteDate date, double rangeRate, MeasurementQuality measurementQuality, SignalTravelTimeModel signalTravelTimeModel, ObservableSatellite satellite)	Simple constructor.

Method Summary

Modifier and Type	Method	Description
protected EstimatedMeasurement<BistaticRangeRate>	theoreticalEvaluation(int iteration, int evaluation, SpacecraftState[] states)	Estimate the theoretical value.
protected EstimatedMeasurementBase<BistaticRangeRate>	theoreticalEvaluationWithoutDerivatives(int iteration, int evaluation, SpacecraftState[] states, boolean fillParticipants)	Estimate the theoretical value without derivatives.

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

fillEstimation, getEmitter, getEmitterStation, getFieldShifts, getReceiver, getReceiverStation, getShifts, getTwoLeggedSignalTimer

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, theoreticalEvaluationWithoutDerivatives

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

BistaticRangeRate

public BistaticRangeRate(Observer emitter,
 Observer receiver,
 AbsoluteDate date,
 double rangeRate,
 double sigma,
 double baseWeight,
 ObservableSatellite satellite)

Simple constructor.

Parameters:

emitter - emitter object

receiver - receiver object

date - date of the measurement

rangeRate - observed value, m/s

sigma - theoretical standard deviation

baseWeight - base weight

satellite - satellite related to this measurement

BistaticRangeRate

public BistaticRangeRate(Observer emitter,
 Observer receiver,
 AbsoluteDate date,
 double rangeRate,
 MeasurementQuality measurementQuality,
 SignalTravelTimeModel signalTravelTimeModel,
 ObservableSatellite satellite)

Simple constructor.

Parameters:

emitter - emitter object

receiver - receiver object

date - date of the measurement

rangeRate - observed value, m/s

measurementQuality - measurement quality data as used in orbit determination

signalTravelTimeModel - signal travel time model

satellite - satellite related to this measurement

Since:

14.0

Method Details

theoreticalEvaluationWithoutDerivatives

protected EstimatedMeasurementBase<BistaticRangeRate> theoreticalEvaluationWithoutDerivatives(int iteration,
 int evaluation,
 SpacecraftState[] states,
 boolean fillParticipants)

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<BistaticRangeRate>

Parameters:

iteration - iteration number

evaluation - evaluation number

states - orbital states at measurement date

fillParticipants - flag to compute and store participants dynamical states at measurement date and along signal path if applicable

Returns:

theoretical value

See Also:

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

theoreticalEvaluation

protected EstimatedMeasurement<BistaticRangeRate> 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<BistaticRangeRate>

Parameters:

iteration - iteration number

evaluation - evaluation number

states - orbital states at measurement date

Returns:

theoretical value

See Also:

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