Package org.orekit.estimation.sequential

Class SemiAnalyticalKalmanModel

java.lang.Object

org.orekit.estimation.sequential.SemiAnalyticalKalmanModel

All Implemented Interfaces:

NonLinearProcess<MeasurementDecorator>, KalmanEstimation, SemiAnalyticalProcess

public class SemiAnalyticalKalmanModel
extends Object
implements KalmanEstimation, NonLinearProcess<MeasurementDecorator>, SemiAnalyticalProcess

Process model to use with a SemiAnalyticalKalmanEstimator.

Since:

11.1

Author:

Julie Bayard, Bryan Cazabonne, Maxime Journot

See Also:

• "Folcik Z., Orbit Determination Using Modern Filters/Smoothers and Continuous Thrust Modeling, Master of Science Thesis, Department of Aeronautics and Astronautics, MIT, June, 2008."
• "Cazabonne B., Bayard J., Journot M., and Cefola P. J., A Semi-analytical Approach for Orbit Determination based on Extended Kalman Filter, AAS Paper 21-614, AAS/AIAA Astrodynamics Specialist Conference, Big Sky, August 2021."

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	SemiAnalyticalKalmanModel(DSSTPropagatorBuilder propagatorBuilder, CovarianceMatrixProvider covarianceMatrixProvider, ParameterDriversList estimatedMeasurementParameters, CovarianceMatrixProvider measurementProcessNoiseMatrix)	Kalman process model constructor (package private).

Method Summary

Modifier and Type	Method	Description
void	finalizeEstimation(ObservedMeasurement<?> observedMeasurement, ProcessEstimate estimate)	Finalize estimation.
void	finalizeOperationsObservationGrid()	Finalize estimation operations on the observation grid.
EstimatedMeasurement<?>	getCorrectedMeasurement()	Get the estimated measurement.
SpacecraftState[]	getCorrectedSpacecraftStates()	Get the corrected spacecraft states.
AbsoluteDate	getCurrentDate()	Get the current date.
int	getCurrentMeasurementNumber()	Get the current measurement number.
ProcessEstimate	getEstimate()	Get the current corrected estimate.
ParameterDriversList	getEstimatedMeasurementsParameters()	Get the list of estimated measurements parameters.
ParameterDriversList	getEstimatedOrbitalParameters()	Get the list of estimated orbital parameters.
ParameterDriversList	getEstimatedPropagationParameters()	Get the list of estimated propagation parameters.
DSSTPropagator	getEstimatedPropagator()	Get the propagator estimated with the values set in the propagator builder.
NonLinearEvolution	getEvolution(double previousTime, RealVector previousState, MeasurementDecorator measurement)
RealVector	getInnovation(MeasurementDecorator measurement, NonLinearEvolution evolution, RealMatrix innovationCovarianceMatrix)
KalmanObserver	getObserver()	Get the observer for Kalman Filter estimations.
RealMatrix	getPhysicalEstimatedCovarianceMatrix()	Get the "physical" estimated covariance matrix (i.e. not normalized)
RealVector	getPhysicalEstimatedState()	Get the "physical" estimated state (i.e. not normalized)
RealMatrix	getPhysicalInnovationCovarianceMatrix()	Get the physical innovation covariance matrix.
RealMatrix	getPhysicalKalmanGain()	Get the physical Kalman gain matrix.
RealMatrix	getPhysicalMeasurementJacobian()	Get the physical Jacobian of the measurement with respect to the state (H matrix).
RealMatrix	getPhysicalStateTransitionMatrix()	Get physical state transition matrix between previous state and estimated (but not yet corrected) state.
EstimatedMeasurement<?>	getPredictedMeasurement()	Get the predicted measurement.
SpacecraftState[]	getPredictedSpacecraftStates()	Get the predicted spacecraft states.
protected double[]	getScale()	Getter for the scale.
void	initializeShortPeriodicTerms(SpacecraftState meanState)	Initialize the short periodic terms for the Kalman Filter.
DSSTPropagator	processMeasurements(List<ObservedMeasurement<?>> observedMeasurements, ExtendedKalmanFilter<MeasurementDecorator> filter)	Process a single measurement.
void	setObserver(KalmanObserver observer)	Set the observer.
void	updateNominalSpacecraftState(SpacecraftState nominal)	Update the nominal spacecraft state.
void	updateReferenceTrajectory(DSSTPropagator propagator)	Update the reference trajectories using the propagator as input.
void	updateShortPeriods(SpacecraftState state)	Update the DSST short periodic terms.

Methods inherited from class java.lang.Object

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

Constructor Details

SemiAnalyticalKalmanModel

protected SemiAnalyticalKalmanModel(DSSTPropagatorBuilder propagatorBuilder,
 CovarianceMatrixProvider covarianceMatrixProvider,
 ParameterDriversList estimatedMeasurementParameters,
 CovarianceMatrixProvider measurementProcessNoiseMatrix)

Kalman process model constructor (package private).

Parameters:

propagatorBuilder - propagators builders used to evaluate the orbits.

covarianceMatrixProvider - provider for covariance matrix

estimatedMeasurementParameters - measurement parameters to estimate

measurementProcessNoiseMatrix - provider for measurement process noise matrix

Method Details

getObserver

public KalmanObserver getObserver()

Get the observer for Kalman Filter estimations.

Specified by:

getObserver in interface SemiAnalyticalProcess

Returns:

the observer for Kalman Filter estimations

setObserver

public void setObserver(KalmanObserver observer)

Set the observer.

Parameters:

observer - the observer

getEstimate

public ProcessEstimate getEstimate()

Get the current corrected estimate.

Returns:

current corrected estimate

getScale

protected double[] getScale()

Getter for the scale.

Returns:

the scale

processMeasurements

public DSSTPropagator processMeasurements(List<ObservedMeasurement<?>> observedMeasurements,
 ExtendedKalmanFilter<MeasurementDecorator> filter)

Process a single measurement.

Update the filter with the new measurements.

Parameters:

observedMeasurements - the list of measurements to process

filter - Extended Kalman Filter

Returns:

estimated propagator

getEstimatedPropagator

public DSSTPropagator getEstimatedPropagator()

Get the propagator estimated with the values set in the propagator builder.

Returns:

propagator based on the current values in the builder

getEvolution

public NonLinearEvolution getEvolution(double previousTime,
 RealVector previousState,
 MeasurementDecorator measurement)

Specified by:

getEvolution in interface NonLinearProcess<MeasurementDecorator>

getInnovation

public RealVector getInnovation(MeasurementDecorator measurement,
 NonLinearEvolution evolution,
 RealMatrix innovationCovarianceMatrix)

Specified by:

getInnovation in interface NonLinearProcess<MeasurementDecorator>

finalizeEstimation

public void finalizeEstimation(ObservedMeasurement<?> observedMeasurement,
 ProcessEstimate estimate)

Finalize estimation.

Specified by:

finalizeEstimation in interface SemiAnalyticalProcess

Parameters:

observedMeasurement - measurement that has just been processed

estimate - corrected estimate

finalizeOperationsObservationGrid

public void finalizeOperationsObservationGrid()

Finalize estimation operations on the observation grid.

Specified by:

finalizeOperationsObservationGrid in interface SemiAnalyticalProcess

getEstimatedOrbitalParameters

public ParameterDriversList getEstimatedOrbitalParameters()

Get the list of estimated orbital parameters.

Specified by:

getEstimatedOrbitalParameters in interface KalmanEstimation

Returns:

the list of estimated orbital parameters

getEstimatedPropagationParameters

public ParameterDriversList getEstimatedPropagationParameters()

Get the list of estimated propagation parameters.

Specified by:

getEstimatedPropagationParameters in interface KalmanEstimation

Returns:

the list of estimated propagation parameters

getEstimatedMeasurementsParameters

public ParameterDriversList getEstimatedMeasurementsParameters()

Get the list of estimated measurements parameters.

Specified by:

getEstimatedMeasurementsParameters in interface KalmanEstimation

Returns:

the list of estimated measurements parameters

getPredictedSpacecraftStates

public SpacecraftState[] getPredictedSpacecraftStates()

Get the predicted spacecraft states.

Specified by:

getPredictedSpacecraftStates in interface KalmanEstimation

Returns:

predicted spacecraft states

getCorrectedSpacecraftStates

public SpacecraftState[] getCorrectedSpacecraftStates()

Get the corrected spacecraft states.

Specified by:

getCorrectedSpacecraftStates in interface KalmanEstimation

Returns:

corrected spacecraft states

getPhysicalEstimatedState

public RealVector getPhysicalEstimatedState()

Get the "physical" estimated state (i.e. not normalized)

Specified by:

getPhysicalEstimatedState in interface KalmanEstimation

Returns:

the "physical" estimated state

getPhysicalEstimatedCovarianceMatrix

public RealMatrix getPhysicalEstimatedCovarianceMatrix()

Get the "physical" estimated covariance matrix (i.e. not normalized)

Specified by:

getPhysicalEstimatedCovarianceMatrix in interface KalmanEstimation

Returns:

the "physical" estimated covariance matrix

getPhysicalStateTransitionMatrix

public RealMatrix getPhysicalStateTransitionMatrix()

Get physical state transition matrix between previous state and estimated (but not yet corrected) state.

Specified by:

getPhysicalStateTransitionMatrix in interface KalmanEstimation

Returns:

state transition matrix between previous state and estimated state (but not yet corrected) (may be null for initial process estimate)

getPhysicalMeasurementJacobian

public RealMatrix getPhysicalMeasurementJacobian()

Get the physical Jacobian of the measurement with respect to the state (H matrix).

Specified by:

getPhysicalMeasurementJacobian in interface KalmanEstimation

Returns:

physical Jacobian of the measurement with respect to the state (may be null for initial process estimate or if the measurement has been ignored)

getPhysicalInnovationCovarianceMatrix

public RealMatrix getPhysicalInnovationCovarianceMatrix()

Get the physical innovation covariance matrix.

Specified by:

getPhysicalInnovationCovarianceMatrix in interface KalmanEstimation

Returns:

physical innovation covariance matrix (may be null for initial process estimate or if the measurement has been ignored)

getPhysicalKalmanGain

public RealMatrix getPhysicalKalmanGain()

Get the physical Kalman gain matrix.

Specified by:

getPhysicalKalmanGain in interface KalmanEstimation

Returns:

Kalman gain matrix (may be null for initial process estimate or if the measurement has been ignored)

getCurrentMeasurementNumber

public int getCurrentMeasurementNumber()

Get the current measurement number.

Specified by:

getCurrentMeasurementNumber in interface KalmanEstimation

Returns:

current measurement number

getCurrentDate

public AbsoluteDate getCurrentDate()

Get the current date.

Specified by:

getCurrentDate in interface KalmanEstimation

Returns:

current date

getPredictedMeasurement

public EstimatedMeasurement<?> getPredictedMeasurement()

Get the predicted measurement.

This estimation has been evaluated on the last predicted orbits

Specified by:

getPredictedMeasurement in interface KalmanEstimation

Returns:

predicted measurement

getCorrectedMeasurement

public EstimatedMeasurement<?> getCorrectedMeasurement()

Get the estimated measurement.

This estimation has been evaluated on the last corrected orbits

Specified by:

getCorrectedMeasurement in interface KalmanEstimation

Returns:

corrected measurement

updateNominalSpacecraftState

public void updateNominalSpacecraftState(SpacecraftState nominal)

Update the nominal spacecraft state.

Specified by:

updateNominalSpacecraftState in interface SemiAnalyticalProcess

Parameters:

nominal - nominal spacecraft state

updateReferenceTrajectory

public void updateReferenceTrajectory(DSSTPropagator propagator)

Update the reference trajectories using the propagator as input.

Parameters:

propagator - The new propagator to use

updateShortPeriods

public void updateShortPeriods(SpacecraftState state)

Update the DSST short periodic terms.

Specified by:

updateShortPeriods in interface SemiAnalyticalProcess

Parameters:

state - current mean state

initializeShortPeriodicTerms

public void initializeShortPeriodicTerms(SpacecraftState meanState)

Initialize the short periodic terms for the Kalman Filter.

Specified by:

initializeShortPeriodicTerms in interface SemiAnalyticalProcess

Parameters:

meanState - mean state for auxiliary elements