Package org.orekit.propagation

Class SpacecraftStateInterpolator

java.lang.Object

org.orekit.time.AbstractTimeInterpolator<SpacecraftState>

org.orekit.propagation.SpacecraftStateInterpolator

All Implemented Interfaces:

TimeInterpolator<SpacecraftState>

public class SpacecraftStateInterpolator
extends AbstractTimeInterpolator<SpacecraftState>

Generic class for spacecraft state interpolator.

The user can specify what interpolator to use for each attribute of the spacecraft state. However, at least one interpolator for either orbit or absolute position-velocity-acceleration is needed. All the other interpolators can be left to null if the user do not want to interpolate these values.

Author:

Luc Maisonobe, Vincent Cucchietti

See Also:

• SpacecraftState

Nested Class Summary

Nested classes/interfaces inherited from class org.orekit.time.AbstractTimeInterpolator

AbstractTimeInterpolator.InterpolationData

Field Summary

Fields inherited from class org.orekit.time.AbstractTimeInterpolator

DEFAULT_EXTRAPOLATION_THRESHOLD_SEC, DEFAULT_INTERPOLATION_POINTS

Constructor Summary

Constructors

Constructor	Description
SpacecraftStateInterpolator(int interpolationPoints, double extrapolationThreshold, Frame outputFrame)	Constructor to create a customizable Hermite interpolator for every spacecraft state field.
SpacecraftStateInterpolator(int interpolationPoints, double extrapolationThreshold, Frame outputFrame, Frame attitudeReferenceFrame)	Constructor to create a customizable Hermite interpolator for every spacecraft state field.
SpacecraftStateInterpolator(int interpolationPoints, double extrapolationThreshold, Frame outputFrame, Frame attitudeReferenceFrame, CartesianDerivativesFilter pvaFilter, AngularDerivativesFilter angularFilter)	Constructor to create a customizable Hermite interpolator for every spacecraft state field.
SpacecraftStateInterpolator(int interpolationPoints, double extrapolationThreshold, Frame outputFrame, TimeInterpolator<Orbit> orbitInterpolator, TimeInterpolator<AbsolutePVCoordinates> absPVAInterpolator, TimeInterpolator<TimeStampedDouble> massInterpolator, TimeInterpolator<Attitude> attitudeInterpolator, TimeInterpolator<TimeStampedDouble> additionalStateInterpolator)	Constructor.
SpacecraftStateInterpolator(int interpolationPoints, Frame outputFrame)	Constructor to create a customizable Hermite interpolator for every spacecraft state field.
SpacecraftStateInterpolator(int interpolationPoints, Frame outputFrame, Frame attitudeReferenceFrame)	Constructor to create a customizable Hermite interpolator for every spacecraft state field.
SpacecraftStateInterpolator(Frame outputFrame)	Simplest constructor to create a default Hermite interpolator for every spacecraft state field.

Method Summary

Modifier and Type	Method	Description
static void	checkSampleAndInterpolatorConsistency(List<SpacecraftState> sample, boolean orbitInterpolatorIsPresent, boolean absPVInterpolatorIsPresent)	Check that an interpolator exist for given sample state definition.
static void	checkStatesDefinitionsConsistency(List<SpacecraftState> states)	Check that all state are either orbit defined or based on absolute position-velocity-acceleration.
Optional<TimeInterpolator<AbsolutePVCoordinates>>	getAbsPVAInterpolator()	Get absolute position-velocity-acceleration interpolator.
Optional<TimeInterpolator<TimeStampedDouble>>	getAdditionalStateInterpolator()	Get additional state interpolator.
Optional<TimeInterpolator<Attitude>>	getAttitudeInterpolator()	Get attitude interpolator.
Optional<TimeInterpolator<TimeStampedDouble>>	getMassInterpolator()	Get mass interpolator.
Optional<TimeInterpolator<Orbit>>	getOrbitInterpolator()	Get orbit interpolator.
Frame	getOutputFrame()	Get output frame.
List<TimeInterpolator<? extends TimeStamped>>	getSubInterpolators()	Get all lowest level interpolators implemented by this instance, otherwise return a list with this instance only.
SpacecraftState	interpolate(AbsoluteDate interpolationDate, Collection<SpacecraftState> sample)	Get an interpolated instance.
protected SpacecraftState	interpolate(AbstractTimeInterpolator<SpacecraftState>.InterpolationData interpolationData)	Interpolate instance from given interpolation data.

Methods inherited from class org.orekit.time.AbstractTimeInterpolator

addOptionalSubInterpolatorIfDefined, checkInterpolatorCompatibilityWithSampleSize, getCentralDate, getCentralDate, getExtrapolationThreshold, getInternalNbInterpolationPoints, getNbInterpolationPoints, getTimeParameter, interpolate

Methods inherited from class java.lang.Object

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

Constructor Details

SpacecraftStateInterpolator

public SpacecraftStateInterpolator(Frame outputFrame)

Simplest constructor to create a default Hermite interpolator for every spacecraft state field.

The interpolators will have the following configuration :

• Same frame for coordinates and attitude
• Default number of interpolation points of DEFAULT_INTERPOLATION_POINTS
• Default extrapolation threshold of DEFAULT_EXTRAPOLATION_THRESHOLD_SEC s
• Use of position and two time derivatives for absolute position-velocity-acceleration coordinates interpolation
• Use of angular and first time derivative for attitude interpolation

As this implementation of interpolation is polynomial, it should be used only with small number of interpolation points (about 10-20 points) in order to avoid Runge's phenomenon and numerical problems (including NaN appearing).

BEWARE: output frame must be inertial if this instance is going to interpolate between tabulated spacecraft states defined by orbit, will throw an error otherwise.

Parameters:

outputFrame - output frame

See Also:

• AbstractTimeInterpolator

SpacecraftStateInterpolator

public SpacecraftStateInterpolator(int interpolationPoints,
 Frame outputFrame)

Constructor to create a customizable Hermite interpolator for every spacecraft state field.

The interpolators will have the following configuration :

• Same frame for coordinates and attitude
• Default extrapolation threshold of DEFAULT_EXTRAPOLATION_THRESHOLD_SEC s
• Use of position and two time derivatives for absolute position-velocity-acceleration coordinates interpolation
• Use of angular and first time derivative for attitude interpolation

As this implementation of interpolation is polynomial, it should be used only with small number of interpolation points (about 10-20 points) in order to avoid Runge's phenomenon and numerical problems (including NaN appearing).

BEWARE: output frame must be inertial if this instance is going to interpolate between tabulated spacecraft states defined by orbit, will throw an error otherwise.

Parameters:

interpolationPoints - number of interpolation points

outputFrame - output frame

See Also:

• AbstractTimeInterpolator

SpacecraftStateInterpolator

public SpacecraftStateInterpolator(int interpolationPoints,
 double extrapolationThreshold,
 Frame outputFrame)

Constructor to create a customizable Hermite interpolator for every spacecraft state field.

The interpolators will have the following configuration :

• Same frame for coordinates and attitude
• Use of position and two time derivatives for absolute position-velocity-acceleration coordinates interpolation
• Use of angular and first time derivative for attitude interpolation

As this implementation of interpolation is polynomial, it should be used only with small number of interpolation points (about 10-20 points) in order to avoid Runge's phenomenon and numerical problems (including NaN appearing).

BEWARE: output frame must be inertial if this instance is going to interpolate between tabulated spacecraft states defined by orbit, will throw an error otherwise.

Parameters:

interpolationPoints - number of interpolation points

extrapolationThreshold - extrapolation threshold beyond which the propagation will fail

outputFrame - output frame

Since:

12.1

See Also:

• AbstractTimeInterpolator

SpacecraftStateInterpolator

public SpacecraftStateInterpolator(int interpolationPoints,
 Frame outputFrame,
 Frame attitudeReferenceFrame)

Constructor to create a customizable Hermite interpolator for every spacecraft state field.

The interpolators will have the following configuration :

• Default extrapolation threshold of DEFAULT_EXTRAPOLATION_THRESHOLD_SEC s
• Use of position and two time derivatives for absolute position-velocity-acceleration coordinates interpolation
• Use of angular and first time derivative for attitude interpolation

As this implementation of interpolation is polynomial, it should be used only with small number of interpolation points (about 10-20 points) in order to avoid Runge's phenomenon and numerical problems (including NaN appearing).

BEWARE: output frame must be inertial if this instance is going to interpolate between tabulated spacecraft states defined by orbit, will throw an error otherwise.

Parameters:

interpolationPoints - number of interpolation points

outputFrame - output frame

attitudeReferenceFrame - reference frame from which attitude is defined

See Also:

• AbstractTimeInterpolator

SpacecraftStateInterpolator

public SpacecraftStateInterpolator(int interpolationPoints,
 double extrapolationThreshold,
 Frame outputFrame,
 Frame attitudeReferenceFrame)

Constructor to create a customizable Hermite interpolator for every spacecraft state field.

The interpolators will have the following configuration :

• Use of position and two time derivatives for absolute position-velocity-acceleration coordinates interpolation
• Use of angular and first time derivative for attitude interpolation

As this implementation of interpolation is polynomial, it should be used only with small number of interpolation points (about 10-20 points) in order to avoid Runge's phenomenon and numerical problems (including NaN appearing).

BEWARE: output frame must be inertial if this instance is going to interpolate between tabulated spacecraft states defined by orbit, will throw an error otherwise.

Parameters:

interpolationPoints - number of interpolation points

extrapolationThreshold - extrapolation threshold beyond which the propagation will fail

outputFrame - output frame

attitudeReferenceFrame - reference frame from which attitude is defined

SpacecraftStateInterpolator

public SpacecraftStateInterpolator(int interpolationPoints,
 double extrapolationThreshold,
 Frame outputFrame,
 Frame attitudeReferenceFrame,
 CartesianDerivativesFilter pvaFilter,
 AngularDerivativesFilter angularFilter)

Constructor to create a customizable Hermite interpolator for every spacecraft state field.

As this implementation of interpolation is polynomial, it should be used only with small number of interpolation points (about 10-20 points) in order to avoid Runge's phenomenon and numerical problems (including NaN appearing).

BEWARE: output frame must be inertial if this instance is going to interpolate between tabulated spacecraft states defined by orbit, will throw an error otherwise.

Parameters:

interpolationPoints - number of interpolation points

extrapolationThreshold - extrapolation threshold beyond which the propagation will fail

outputFrame - output frame

attitudeReferenceFrame - reference frame from which attitude is defined

pvaFilter - filter for derivatives from the sample to use in position-velocity-acceleration interpolation

angularFilter - filter for derivatives from the sample to use in attitude interpolation

SpacecraftStateInterpolator

public SpacecraftStateInterpolator(int interpolationPoints,
 double extrapolationThreshold,
 Frame outputFrame,
 TimeInterpolator<Orbit> orbitInterpolator,
 TimeInterpolator<AbsolutePVCoordinates> absPVAInterpolator,
 TimeInterpolator<TimeStampedDouble> massInterpolator,
 TimeInterpolator<Attitude> attitudeInterpolator,
 TimeInterpolator<TimeStampedDouble> additionalStateInterpolator)

Constructor.

At least one interpolator for either orbit or absolute position-velocity-acceleration is needed. All the other interpolators can be left to null if the user do not want to interpolate these values.

BEWARE: output frame must be inertial if interpolated spacecraft states are defined by orbit. Throws an error otherwise.

BEWARE: it is up to the user to check the consistency of input interpolators.

Parameters:

interpolationPoints - number of interpolation points

extrapolationThreshold - extrapolation threshold beyond which the propagation will fail

outputFrame - output frame (inertial if the user is planning to use the orbit interpolator)

orbitInterpolator - orbit interpolator (can be null if absPVAInterpolator is defined)

absPVAInterpolator - absolute position-velocity-acceleration (can be null if orbitInterpolator is defined)

massInterpolator - mass interpolator (can be null)

attitudeInterpolator - attitude interpolator (can be null)

additionalStateInterpolator - additional state interpolator (can be null)

Since:

12.0.1

Method Details

checkSampleAndInterpolatorConsistency

public static void checkSampleAndInterpolatorConsistency(List<SpacecraftState> sample,
 boolean orbitInterpolatorIsPresent,
 boolean absPVInterpolatorIsPresent)

Check that an interpolator exist for given sample state definition.

Parameters:

sample - sample (non empty)

orbitInterpolatorIsPresent - flag defining if an orbit interpolator has been defined for this instance

absPVInterpolatorIsPresent - flag defining if an absolute position-velocity-acceleration interpolator has been defined for this instance

Throws:

OrekitIllegalArgumentException - if there is no defined interpolator for given sample spacecraft state definition type

checkStatesDefinitionsConsistency

public static void checkStatesDefinitionsConsistency(List<SpacecraftState> states)

Check that all state are either orbit defined or based on absolute position-velocity-acceleration.

Parameters:

states - spacecraft state sample

interpolate

public SpacecraftState interpolate(AbsoluteDate interpolationDate,
 Collection<SpacecraftState> sample)

Get an interpolated instance..

The additional states that are interpolated are the ones already present in the first neighbor instance. The sample instances must therefore have at least the same additional states as this neighbor instance. They may have more additional states, but the extra ones will be ignored.

All the sample instances must be based on similar trajectory data, i.e. they must either all be based on orbits or all be based on absolute position-velocity-acceleration. Any inconsistency will trigger an OrekitIllegalArgumentException.

Specified by:

interpolate in interface TimeInterpolator<SpacecraftState>

Overrides:

interpolate in class AbstractTimeInterpolator<SpacecraftState>

Parameters:

interpolationDate - interpolation date

sample - time stamped sample

Returns:

a new instance, interpolated at specified date

Throws:

OrekitIllegalArgumentException - if there are states defined by orbits and absolute position-velocity-acceleration coordinates

OrekitIllegalArgumentException - if there is no defined interpolator for given sample spacecraft state definition type

getSubInterpolators

public List<TimeInterpolator<? extends TimeStamped>> getSubInterpolators()

Get all lowest level interpolators implemented by this instance, otherwise return a list with this instance only.

An example would be the spacecraft state interpolator which can use different interpolators for each of its attributes (orbit, absolute position-velocity-acceleration coordinates, mass...). In this case, it would return the list of all of these interpolators (or possibly all of their sub-interpolators if they were to use multiple interpolators themselves).

Specified by:

getSubInterpolators in interface TimeInterpolator<SpacecraftState>

Overrides:

getSubInterpolators in class AbstractTimeInterpolator<SpacecraftState>

Returns:

list of interpolators

interpolate

protected SpacecraftState interpolate(AbstractTimeInterpolator<SpacecraftState>.InterpolationData interpolationData)

Interpolate instance from given interpolation data.

Specified by:

interpolate in class AbstractTimeInterpolator<SpacecraftState>

Parameters:

interpolationData - interpolation data

Returns:

interpolated instance from given interpolation data.

getOutputFrame

public Frame getOutputFrame()

Get output frame.

Returns:

output frame

getOrbitInterpolator

public Optional<TimeInterpolator<Orbit>> getOrbitInterpolator()

Get orbit interpolator.

Returns:

optional orbit interpolator

See Also:

• Optional

getAbsPVAInterpolator

public Optional<TimeInterpolator<AbsolutePVCoordinates>> getAbsPVAInterpolator()

Get absolute position-velocity-acceleration interpolator.

Returns:

optional absolute position-velocity-acceleration interpolator

See Also:

• Optional

getMassInterpolator

public Optional<TimeInterpolator<TimeStampedDouble>> getMassInterpolator()

Get mass interpolator.

Returns:

optional mass interpolator

See Also:

• Optional

getAttitudeInterpolator

public Optional<TimeInterpolator<Attitude>> getAttitudeInterpolator()

Get attitude interpolator.

Returns:

optional attitude interpolator

See Also:

• Optional

getAdditionalStateInterpolator

public Optional<TimeInterpolator<TimeStampedDouble>> getAdditionalStateInterpolator()

Get additional state interpolator.

Returns:

optional additional state interpolator

See Also:

• Optional