Package org.orekit.estimation.measurements.gnss

Class OneWayGNSSPhase

java.lang.Object

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

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

org.orekit.estimation.measurements.gnss.AbstractOneWayGNSS<OneWayGNSSPhase>

org.orekit.estimation.measurements.gnss.OneWayGNSSPhase

All Implemented Interfaces:

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

public class OneWayGNSSPhase
extends AbstractOneWayGNSS<OneWayGNSSPhase>

One-way GNSS phase measurement.

This class can be used in precise orbit determination applications for modeling a phase measurement between a GNSS emitter and a LEO satellite (receiver).

The one-way GNSS phase measurement assumes knowledge of the orbit and the clock offset of the emitting GNSS satellite. For instance, it is possible to use a SP3 file or a GNSS navigation message to recover the satellite's orbit and clock.

This class is very similar to InterSatellitesPhase measurement class. However, using the one-way GNSS phase measurement, the orbit and clock of the emitting GNSS satellite are NOT estimated simultaneously with LEO satellite coordinates.

Since:

10.3

Author:

Bryan Cazabonne

Field Summary

Fields

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

Constructor Summary

Constructors

Constructor	Description
OneWayGNSSPhase(Observer observer, AbsoluteDate date, double phase, double wavelength, double sigma, double baseWeight, ObservableSatellite local, AmbiguityCache cache)	Simple constructor.
OneWayGNSSPhase(Observer observer, AbsoluteDate date, double phase, double wavelength, MeasurementQuality measurementQuality, SignalTravelTimeModel signalTravelTimeModel, ObservableSatellite local, AmbiguityCache cache)	Simple constructor.

Method Summary

Modifier and Type	Method	Description
AmbiguityDriver	getAmbiguityDriver()	Get the driver for phase ambiguity.
double	getWavelength()	Get the wavelength.
protected EstimatedMeasurement<OneWayGNSSPhase>	theoreticalEvaluation(int iteration, int evaluation, SpacecraftState[] states)	Estimate the theoretical value.
protected EstimatedMeasurementBase<OneWayGNSSPhase>	theoreticalEvaluationWithoutDerivatives(int iteration, int evaluation, SpacecraftState[] states)	Estimate the theoretical value without derivatives.

Methods inherited from class org.orekit.estimation.measurements.gnss.AbstractOneWayGNSS

fillDerivatives, getObserver

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

OneWayGNSSPhase

public OneWayGNSSPhase(Observer observer,
 AbsoluteDate date,
 double phase,
 double wavelength,
 double sigma,
 double baseWeight,
 ObservableSatellite local,
 AmbiguityCache cache)

Simple constructor.

Parameters:

observer - object that sends signal

date - date of the measurement

phase - observed value, in cycles

wavelength - phase observed value wavelength, in meters

sigma - theoretical standard deviation

baseWeight - base weight

local - satellite which receives the signal and perform the measurement

cache - from which ambiguity drive should come

Since:

12.1

OneWayGNSSPhase

public OneWayGNSSPhase(Observer observer,
 AbsoluteDate date,
 double phase,
 double wavelength,
 MeasurementQuality measurementQuality,
 SignalTravelTimeModel signalTravelTimeModel,
 ObservableSatellite local,
 AmbiguityCache cache)

Simple constructor.

Parameters:

observer - object that sends signal

date - date of the measurement

phase - observed value, in cycles

wavelength - phase observed value wavelength, in meters

measurementQuality - measurement quality data as used in orbit determination

signalTravelTimeModel - signal model

local - satellite which receives the signal and perform the measurement

cache - from which ambiguity drive should come

Since:

14.0

Method Details

getWavelength

public double getWavelength()

Get the wavelength.

Returns:

wavelength (m)

getAmbiguityDriver

public AmbiguityDriver getAmbiguityDriver()

Get the driver for phase ambiguity.

Returns:

the driver for phase ambiguity

theoreticalEvaluationWithoutDerivatives

protected EstimatedMeasurementBase<OneWayGNSSPhase> 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<OneWayGNSSPhase>

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<OneWayGNSSPhase> 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<OneWayGNSSPhase>

Parameters:

iteration - iteration number

evaluation - evaluation number

states - orbital states at measurement date

Returns:

theoretical value

See Also:

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