org.orekit.estimation.measurements

Class BistaticRangeRate

java.lang.Object

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

org.orekit.estimation.measurements.BistaticRangeRate

All Implemented Interfaces:

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

public class BistaticRangeRate
extends AbstractMeasurement<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

Constructor Summary

Constructors

Constructor and Description
BistaticRangeRate(GroundStation emitter, GroundStation receiver, AbsoluteDate date, double rangeRate, double sigma, double baseWeight, ObservableSatellite satellite) Simple constructor.

Method Summary

Modifier and Type	Method and Description
GroundStation	getEmitterStation() Get the emitter ground station.
GroundStation	getReceiverStation() Get the receiver ground station.
protected EstimatedMeasurement<BistaticRangeRate>	theoreticalEvaluation(int iteration, int evaluation, SpacecraftState[] states) Estimate the theoretical value.

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

addModifier, addParameterDriver, estimate, getBaseWeight, getCoordinates, getDate, getDimension, getModifiers, getObservedValue, getParametersDrivers, getSatellites, getTheoreticalStandardDeviation, isEnabled, setEnabled, signalTimeOfFlight, signalTimeOfFlight

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

Constructor Detail

BistaticRangeRate

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

Simple constructor.

Parameters:

emitter - emitter ground station

receiver - receiver ground station

date - date of the measurement

rangeRate - observed value, m/s

sigma - theoretical standard deviation

baseWeight - base weight

satellite - satellite related to this measurement

Method Detail

getEmitterStation

public GroundStation getEmitterStation()

Get the emitter ground station.

Returns:

emitter ground station

getReceiverStation

public GroundStation getReceiverStation()

Get the receiver ground station.

Returns:

receiver ground station

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[])