Package org.orekit.propagation.semianalytical.dsst.forces

Class DSSTTesseral

java.lang.Object

org.orekit.propagation.semianalytical.dsst.forces.DSSTTesseral

All Implemented Interfaces:

DSSTForceModel

public class DSSTTesseral
extends Object
implements DSSTForceModel

Tesseral contribution to the central body gravitational perturbation.

Only resonant tesserals are considered.

Author:

Romain Di Costanzo, Pascal Parraud

Constructor Summary

Constructors

Constructor	Description
DSSTTesseral(Frame centralBodyFrame, double centralBodyRotationRate, UnnormalizedSphericalHarmonicsProvider provider, int maxDegreeTesseralSP, int maxOrderTesseralSP, int maxEccPowTesseralSP, int maxFrequencyShortPeriodics, int maxDegreeMdailyTesseralSP, int maxOrderMdailyTesseralSP, int maxEccPowMdailyTesseralSP)	Simple constructor.

Method Summary

Modifier and Type	Method	Description
EventDetector[]	getEventsDetectors()	Get the discrete events related to the model.
double[]	getMeanElementRate(SpacecraftState spacecraftState)	Computes the mean equinoctial elements rates dai / dt.
List<ShortPeriodTerms>	initialize(AuxiliaryElements aux, boolean meanOnly)	Performs initialization prior to propagation for the current force model.
void	initializeStep(AuxiliaryElements aux)	Performs initialization at each integration step for the current force model.
void	registerAttitudeProvider(AttitudeProvider attitudeProvider)	Register an attitude provider.
void	updateShortPeriodTerms(SpacecraftState... meanStates)	Update the short period terms.

Methods inherited from class java.lang.Object

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

Constructor Detail

DSSTTesseral

public DSSTTesseral(Frame centralBodyFrame,
                    double centralBodyRotationRate,
                    UnnormalizedSphericalHarmonicsProvider provider,
                    int maxDegreeTesseralSP,
                    int maxOrderTesseralSP,
                    int maxEccPowTesseralSP,
                    int maxFrequencyShortPeriodics,
                    int maxDegreeMdailyTesseralSP,
                    int maxOrderMdailyTesseralSP,
                    int maxEccPowMdailyTesseralSP)

Simple constructor.

Parameters:

centralBodyFrame - rotating body frame

centralBodyRotationRate - central body rotation rate (rad/s)

provider - provider for spherical harmonics

maxDegreeTesseralSP - maximal degree to consider for short periodics tesseral harmonics potential (must be between 2 and provider.getMaxDegree())

maxOrderTesseralSP - maximal order to consider for short periodics tesseral harmonics potential (must be between 0 and provider.getMaxOrder())

maxEccPowTesseralSP - maximum power of the eccentricity to use in summation over s for short periodic tesseral harmonics (without m-daily), should typically not exceed 4 as higher values will exceed computer capacity

maxFrequencyShortPeriodics - maximum frequency in mean longitude for short periodic computations (typically maxDegreeTesseralSP + maxEccPowTesseralSP and no more than 12)

maxDegreeMdailyTesseralSP - maximal degree to consider for short periodics m-daily tesseral harmonics potential (must be between 2 and provider.getMaxDegree())

maxOrderMdailyTesseralSP - maximal order to consider for short periodics m-daily tesseral harmonics potential (must be between 0 and provider.getMaxOrder())

maxEccPowMdailyTesseralSP - maximum power of the eccentricity to use in summation over s for m-daily tesseral harmonics, (must be between 0 and maxDegreeMdailyTesseralSP - 2, but should typically not exceed 4 as higher values will exceed computer capacity)

Since:

7.2

Method Detail

initialize

public List<ShortPeriodTerms> initialize(AuxiliaryElements aux,
                                         boolean meanOnly)

Performs initialization prior to propagation for the current force model.

This method aims at being called at the very beginning of a propagation.

Specified by:

initialize in interface DSSTForceModel

Parameters:

aux - auxiliary elements related to the current orbit

meanOnly - only mean elements are used during the propagation

Returns:

a list of objects that will hold short period terms (the objects are also retained by the force model, which will update them during propagation)

initializeStep

public void initializeStep(AuxiliaryElements aux)

Performs initialization at each integration step for the current force model.

This method aims at being called before mean elements rates computation.

Specified by:

initializeStep in interface DSSTForceModel

Parameters:

aux - auxiliary elements related to the current orbit

getMeanElementRate

public double[] getMeanElementRate(SpacecraftState spacecraftState)

Computes the mean equinoctial elements rates da_i / dt.

Specified by:

getMeanElementRate in interface DSSTForceModel

Parameters:

spacecraftState - current state information: date, kinematics, attitude

Returns:

the mean element rates dai/dt

updateShortPeriodTerms

public void updateShortPeriodTerms(SpacecraftState... meanStates)

Update the short period terms.

The short period terms that will be updated are the ones that were returned during the call to DSSTForceModel.initialize(AuxiliaryElements, boolean).

Specified by:

updateShortPeriodTerms in interface DSSTForceModel

Parameters:

meanStates - mean states information: date, kinematics, attitude

getEventsDetectors

public EventDetector[] getEventsDetectors()

Get the discrete events related to the model.

Specified by:

getEventsDetectors in interface DSSTForceModel

Returns:

array of events detectors or null if the model is not related to any discrete events

registerAttitudeProvider

public void registerAttitudeProvider(AttitudeProvider attitudeProvider)

Register an attitude provider.

Register an attitude provider that can be used by the force model.

Specified by:

registerAttitudeProvider in interface DSSTForceModel

Parameters:

attitudeProvider - the AttitudeProvider