fr.cnes.sirius.patrius.stela.forces.gravity.recurrence

Class StelaRecurrenceZonalAttraction

java.lang.Object

fr.cnes.sirius.patrius.stela.forces.AbstractStelaLagrangeContribution

fr.cnes.sirius.patrius.stela.forces.gravity.AbstractStelaZonalAttraction

fr.cnes.sirius.patrius.stela.forces.gravity.recurrence.StelaRecurrenceZonalAttraction

All Implemented Interfaces:

StelaForceModel, Serializable

public class StelaRecurrenceZonalAttraction
extends AbstractStelaZonalAttraction

Class representing the Earth zonal harmonics computed using recurrence methods.

Computes Zonal perturbations, short periods and partial derivatives using recurrence methods depending on the degree of development asked.

The class is adapted from STELA RecurrenceZonalAcc in fr.cnes.los.stela.elib.business.implementation.earthpotential.zonal.

Since:

4.16

Author:

Maxime Ecochard, Thibaut BONIT HISTORY VERSION:4.16:OPENFD-391:25/04/2025:[STELA-PATRIUS] Implementation zonaux par recurrence END-HISTORY

See Also:

Serialized Form

Concurrency :

conditionally thread-safe

Concurrency comment :

thread safe if the PotentialCoefficientsProvider used is thread safe

Field Summary

Fields inherited from class fr.cnes.sirius.patrius.stela.forces.gravity.AbstractStelaZonalAttraction

isJ2SquareComputed, zonalDegreeMaxPerturbation

Fields inherited from class fr.cnes.sirius.patrius.stela.forces.AbstractStelaLagrangeContribution

dPot

Constructor Summary

Constructors

Constructor and Description
StelaRecurrenceZonalAttraction(PotentialCoefficientsProvider provider, int zonalDegreeMaxPerturbation) Simple constructor.
StelaRecurrenceZonalAttraction(PotentialCoefficientsProvider provider, int zonalDegreeMaxPerturbation, boolean isJ2SquareComputed, boolean isNormalizedLegendrePolynomials) Constructor with J22 flag.

Method Summary

Modifier and Type	Method and Description
StelaRecurrenceZonalEquation	buildStelaRecurrenceZonalEquation(StelaEquinoctialOrbit orbit) Build the StelaRecurrenceZonalEquation object from this class initialized parameters.
double[]	computeJ2Square(StelaEquinoctialOrbit orbit) Compute the effect of the J2² of the Zonal Perturbation.
double[][]	computePartialDerivatives(StelaEquinoctialOrbit orbit) Compute the partial derivatives for a given spacecraft state.
double[]	computePerturbation(StelaEquinoctialOrbit orbit) Compute the dE/dt force derivatives for a given spacecraft state.
double[]	computeShortPeriods(StelaEquinoctialOrbit orbit, OrbitNatureConverter converter) Compute the short periodic variations for a given spacecraft state.
double[]	derParUdeg22(StelaEquinoctialOrbit orbit) Partial derivative due to 2nd order Earth potential zonal harmonics (J22).
boolean	isNormalizedLegendrePolynomials() Indicate if the zonal perturbation are normalized Legendre Polynomials or not.
double[]	nDegZonalPartialDerivatives(StelaRecurrenceZonalEquation zonalEq, int n) Compute Jn zonal term (n: order of potential development).

Methods inherited from class fr.cnes.sirius.patrius.stela.forces.gravity.AbstractStelaZonalAttraction

getZonalDegreeMaxPerturbation, isJ2SquareComputed

Methods inherited from class fr.cnes.sirius.patrius.stela.forces.AbstractStelaLagrangeContribution

getdPot, getType

Methods inherited from class java.lang.Object

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

Constructor Detail

StelaRecurrenceZonalAttraction

public StelaRecurrenceZonalAttraction(PotentialCoefficientsProvider provider,
                                      int zonalDegreeMaxPerturbation)
                               throws PatriusException

Simple constructor.

By default, this constructor enables the J2² computation and uses normalized Legendre Polynomials for the zonal perturbation.

Parameters:

provider - Gravity field coefficients provider

zonalDegreeMaxPerturbation - degree of development for zonal perturbations

Throws:

PatriusException - if the requested maximal degree exceeds the available degree

NotPositiveException - if zonalDegreeMaxPerturbation < 0

StelaRecurrenceZonalAttraction

public StelaRecurrenceZonalAttraction(PotentialCoefficientsProvider provider,
                                      int zonalDegreeMaxPerturbation,
                                      boolean isJ2SquareComputed,
                                      boolean isNormalizedLegendrePolynomials)
                               throws PatriusException

Constructor with J2² flag.

Parameters:

provider - Gravity field coefficients provider

zonalDegreeMaxPerturbation - degree of development for zonal perturbations

isJ2SquareComputed - if true, J2² is computed

isNormalizedLegendrePolynomials - if true, use normalized Legendre Polynomials for the zonal perturbation

Throws:

PatriusException - if the requested maximal degree exceeds the available degree

NotPositiveException - if zonalDegreeMaxPerturbation < 0

Method Detail

computeShortPeriods

public double[] computeShortPeriods(StelaEquinoctialOrbit orbit,
                                    OrbitNatureConverter converter)

Compute the short periodic variations for a given spacecraft state.

Note: the short periods (forces switches and degrees) are not used for this force model (return 0 array).

Parameters:

orbit - current orbit information: date, kinematics

converter - converter necessary in some specific case (drag short periods computation)

Returns:

the short periodic variations of the current force

computePartialDerivatives

public double[][] computePartialDerivatives(StelaEquinoctialOrbit orbit)
                                     throws PatriusException

Compute the partial derivatives for a given spacecraft state.

Parameters:

orbit - current orbit information: date, kinematics

Returns:

the partial derivatives of the current force

Throws:

PatriusException - if partial derivatives computation fails

computePerturbation

public double[] computePerturbation(StelaEquinoctialOrbit orbit)
                             throws PatriusException

Compute the dE/dt force derivatives for a given spacecraft state.

Specified by:

computePerturbation in class AbstractStelaLagrangeContribution

Parameters:

orbit - current orbit information: date, kinematics

Returns:

the perturbation dE/dt for the current force

Throws:

PatriusException - if perturbation computation fails

computeJ2Square

public double[] computeJ2Square(StelaEquinoctialOrbit orbit)
                         throws PatriusException

Compute the effect of the J2² of the Zonal Perturbation.

Specified by:

computeJ2Square in class AbstractStelaZonalAttraction

Parameters:

orbit - an orbit

Returns:

the J2² perturbation

Throws:

PatriusException - if the provider doesn't support 2nd degree

buildStelaRecurrenceZonalEquation

public StelaRecurrenceZonalEquation buildStelaRecurrenceZonalEquation(StelaEquinoctialOrbit orbit)

Build the StelaRecurrenceZonalEquation object from this class initialized parameters.

Returns:

the StelaRecurrenceZonalEquation object

nDegZonalPartialDerivatives

public double[] nDegZonalPartialDerivatives(StelaRecurrenceZonalEquation zonalEq,
                                            int n)

Compute Jn zonal term (n: order of potential development).

Parameters:

zonalEq - zonal terms

n - order

Returns:

Jn zonal term

derParUdeg22

public double[] derParUdeg22(StelaEquinoctialOrbit orbit)
                      throws PatriusException

Partial derivative due to 2nd order Earth potential zonal harmonics (J22).

Parameters:

orbit - a position-velocity in equinoctial parameters

Returns:

partial derivatives in equinoctial parameters

Throws:

PatriusException - if the provider doesn't support 2nd degree

isNormalizedLegendrePolynomials

public boolean isNormalizedLegendrePolynomials()

Indicate if the zonal perturbation are normalized Legendre Polynomials or not.

Returns:

true if the zonal perturbation are normalized Legendre Polynomials, false otherwise