Package org.orekit.utils

Class AbsolutePVCoordinatesHermiteInterpolator

java.lang.Object

org.orekit.time.AbstractTimeInterpolator<AbsolutePVCoordinates>

org.orekit.utils.AbsolutePVCoordinatesHermiteInterpolator

All Implemented Interfaces:

TimeInterpolator<AbsolutePVCoordinates>

public class AbsolutePVCoordinatesHermiteInterpolator
extends AbstractTimeInterpolator<AbsolutePVCoordinates>

Class using a Hermite interpolator to interpolate absolute position-velocity-acceleration coordinates.

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).

Author:

Luc Maisonobe, Vincent Cucchietti

See Also:

HermiteInterpolator, AbsolutePVCoordinates

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
AbsolutePVCoordinatesHermiteInterpolator(int interpolationPoints, double extrapolationThreshold, Frame outputFrame, CartesianDerivativesFilter filter)	Constructor.
AbsolutePVCoordinatesHermiteInterpolator(int interpolationPoints, Frame outputFrame)	Constructor with : Default extrapolation threshold value (DEFAULT_EXTRAPOLATION_THRESHOLD_SEC s) Use of position and two time derivatives during 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).
AbsolutePVCoordinatesHermiteInterpolator(int interpolationPoints, Frame outputFrame, CartesianDerivativesFilter filter)	Constructor with default extrapolation threshold value (DEFAULT_EXTRAPOLATION_THRESHOLD_SEC s).
AbsolutePVCoordinatesHermiteInterpolator(Frame outputFrame)	Constructor with : Default number of interpolation points of DEFAULT_INTERPOLATION_POINTS Default extrapolation threshold value (DEFAULT_EXTRAPOLATION_THRESHOLD_SEC s) Use of position and two time derivatives during 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).

Method Summary

Modifier and Type	Method	Description
CartesianDerivativesFilter	getFilter()	Get the filter for derivatives from the sample to use in interpolation.
Frame	getOutputFrame()	Get output frame for the interpolated instance.
protected AbsolutePVCoordinates	interpolate(AbstractTimeInterpolator.InterpolationData interpolationData)	Interpolate instance from given interpolation data.

Methods inherited from class org.orekit.time.AbstractTimeInterpolator

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

Methods inherited from class java.lang.Object

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

Constructor Detail

AbsolutePVCoordinatesHermiteInterpolator

public AbsolutePVCoordinatesHermiteInterpolator(Frame outputFrame)

Constructor with :

• Default number of interpolation points of DEFAULT_INTERPOLATION_POINTS
• Default extrapolation threshold value (DEFAULT_EXTRAPOLATION_THRESHOLD_SEC s)
• Use of position and two time derivatives during 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).

Parameters:

outputFrame - frame for the interpolated instance

AbsolutePVCoordinatesHermiteInterpolator

public AbsolutePVCoordinatesHermiteInterpolator(int interpolationPoints,
                                                Frame outputFrame)

Constructor with :

• Default extrapolation threshold value (DEFAULT_EXTRAPOLATION_THRESHOLD_SEC s)
• Use of position and two time derivatives during 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).

Parameters:

interpolationPoints - number of interpolation points

outputFrame - frame for the interpolated instance

AbsolutePVCoordinatesHermiteInterpolator

public AbsolutePVCoordinatesHermiteInterpolator(int interpolationPoints,
                                                Frame outputFrame,
                                                CartesianDerivativesFilter filter)

Constructor with default extrapolation threshold value (DEFAULT_EXTRAPOLATION_THRESHOLD_SEC s).

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).

Parameters:

interpolationPoints - number of interpolation points

outputFrame - frame for the interpolated instance

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

AbsolutePVCoordinatesHermiteInterpolator

public AbsolutePVCoordinatesHermiteInterpolator(int interpolationPoints,
                                                double extrapolationThreshold,
                                                Frame outputFrame,
                                                CartesianDerivativesFilter filter)

Constructor.

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).

Parameters:

interpolationPoints - number of interpolation points

extrapolationThreshold - extrapolation threshold beyond which the propagation will fail

outputFrame - frame for the interpolated instance

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

Method Detail

getFilter

public CartesianDerivativesFilter getFilter()

Get the filter for derivatives from the sample to use in interpolation.

Returns:

filter for derivatives from the sample to use in interpolation.

getOutputFrame

public Frame getOutputFrame()

Get output frame for the interpolated instance.

Returns:

output frame for the interpolated instance

interpolate

protected AbsolutePVCoordinates interpolate(AbstractTimeInterpolator.InterpolationData interpolationData)

Interpolate instance from given interpolation data.

The interpolated instance is created by polynomial Hermite interpolation ensuring velocity remains the exact derivative of position.

Note that even if first time derivatives (velocities) from sample can be ignored, the interpolated instance always includes interpolated derivatives. This feature can be used explicitly to compute these derivatives when it would be too complex to compute them from an analytical formula: just compute a few sample points from the explicit formula and set the derivatives to zero in these sample points, then use interpolation to add derivatives consistent with the positions.

Specified by:

interpolate in class AbstractTimeInterpolator<AbsolutePVCoordinates>

Parameters:

interpolationData - interpolation data

Returns:

interpolated instance from given interpolation data.