org.orekit.estimation.measurements

Class RangeRate

java.lang.Object

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

org.orekit.estimation.measurements.RangeRate

All Implemented Interfaces:

ObservedMeasurement<RangeRate>, TimeStamped

public class RangeRate
extends AbstractMeasurement<RangeRate>

Class modeling one-way or two-way range rate measurement between two vehicles. One-way range rate (or Doppler) measurements generally apply to specific satellites (e.g. GNSS, DORIS), where a signal is transmitted from a satellite to a measuring station. Two-way range rate measurements are applicable to any system. The signal is transmitted to the (non-spinning) satellite and returned by a transponder (or reflected back)to the same measuring station. The Doppler measurement can be obtained by multiplying the velocity by (fe/c), where fe is the emission frequency.

Since:

8.0

Author:

Thierry Ceolin, Joris Olympio

Constructor Summary

Constructors

Constructor and Description
RangeRate(GroundStation station, AbsoluteDate date, double rangeRate, double sigma, double baseWeight, boolean twoway) Simple constructor.
RangeRate(GroundStation station, AbsoluteDate date, double rangeRate, double sigma, double baseWeight, boolean twoway, int propagatorIndex) Simple constructor.

Method Summary

Modifier and Type	Method and Description
GroundStation	getStation() Get the ground station from which measurement is performed.
boolean	isTwoWay() Check if the instance represents a two-way measurement.
protected EstimatedMeasurement<RangeRate>	theoreticalEvaluation(int iteration, int evaluation, SpacecraftState[] states) Estimate the theoretical value.

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

RangeRate

public RangeRate(GroundStation station,
                 AbsoluteDate date,
                 double rangeRate,
                 double sigma,
                 double baseWeight,
                 boolean twoway)
          throws OrekitException

Simple constructor.

This constructor uses 0 as the index of the propagator related to this measurement, thus being well suited for mono-satellite orbit determination.

Parameters:

station - ground station from which measurement is performed

date - date of the measurement

rangeRate - observed value, m/s

sigma - theoretical standard deviation

baseWeight - base weight

twoway - if true, this is a two-way measurement

Throws:

OrekitException - if a ParameterDriver name conflict occurs

RangeRate

public RangeRate(GroundStation station,
                 AbsoluteDate date,
                 double rangeRate,
                 double sigma,
                 double baseWeight,
                 boolean twoway,
                 int propagatorIndex)
          throws OrekitException

Simple constructor.

Parameters:

station - ground station from which measurement is performed

date - date of the measurement

rangeRate - observed value, m/s

sigma - theoretical standard deviation

baseWeight - base weight

twoway - if true, this is a two-way measurement

propagatorIndex - index of the propagator related to this measurement

Throws:

OrekitException - if a ParameterDriver name conflict occurs

Since:

9.0

Method Detail

isTwoWay

public boolean isTwoWay()

Check if the instance represents a two-way measurement.

Returns:

true if the instance represents a two-way measurement

getStation

public GroundStation getStation()

Get the ground station from which measurement is performed.

Returns:

ground station from which measurement is performed

theoreticalEvaluation

protected EstimatedMeasurement<RangeRate> theoreticalEvaluation(int iteration,
                                                                int evaluation,
                                                                SpacecraftState[] states)
                                                         throws OrekitException

Estimate the theoretical value.

The theoretical value does not have any modifiers applied.

Specified by:

theoreticalEvaluation in class AbstractMeasurement<RangeRate>

Parameters:

iteration - iteration number

evaluation - evaluation number

states - orbital states at measurement date

Returns:

theoretical value

Throws:

OrekitException - if value cannot be computed

See Also:

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