org.orekit.propagation.semianalytical.dsst.forces

Class DSSTCentralBody

java.lang.Object

org.orekit.propagation.semianalytical.dsst.forces.DSSTCentralBody

All Implemented Interfaces:

DSSTForceModel

public class DSSTCentralBody
extends Object
implements DSSTForceModel

Central body gravitational contribution to the DSSTPropagator.

Central body gravitational contribution is made of:

1. zonal harmonics contribution
2. tesseral harmonics contribution

Author:

Pascal Parraud

Constructor Summary

Constructors

Constructor and Description
DSSTCentralBody(Frame centralBodyFrame, double centralBodyRotationRate, UnnormalizedSphericalHarmonicsProvider provider) DSST Central body constructor.
DSSTCentralBody(Frame centralBodyFrame, double centralBodyRotationRate, UnnormalizedSphericalHarmonicsProvider provider, boolean mDailiesOnly) DSST Central body constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	computeShortPeriodicsCoefficients(SpacecraftState state) Compute the coefficients used for short periodic variations.
EventDetector[]	getEventsDetectors() Get the discrete events related to the model.
double[]	getMeanElementRate(SpacecraftState spacecraftState) Computes the mean equinoctial elements rates dai / dt.
UnnormalizedSphericalHarmonicsProvider	getProvider() Get the spherical harmonics provider.
double[]	getShortPeriodicVariations(AbsoluteDate date, double[] meanElements) Computes the short periodic variations.
void	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 provider) Register an attitude provider.
void	resetShortPeriodicsCoefficients() Reset the coefficients used for short periodic variations.

Methods inherited from class java.lang.Object

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

Constructor Detail

DSSTCentralBody

public DSSTCentralBody(Frame centralBodyFrame,
               double centralBodyRotationRate,
               UnnormalizedSphericalHarmonicsProvider provider,
               boolean mDailiesOnly)

DSST Central body constructor.

Parameters:

centralBodyFrame - rotating body frame

centralBodyRotationRate - central body rotation rate (rad/s)

provider - provider for spherical harmonics

mDailiesOnly - if true only M-dailies tesseral harmonics are taken into account for short periodics

DSSTCentralBody

public DSSTCentralBody(Frame centralBodyFrame,
               double centralBodyRotationRate,
               UnnormalizedSphericalHarmonicsProvider provider)

DSST Central body constructor.

All harmonics are considered for the short-periodic tesseral contribution

Parameters:

centralBodyFrame - rotating body frame

centralBodyRotationRate - central body rotation rate (rad/s)

provider - provider for spherical harmonics

Method Detail

initialize

public void initialize(AuxiliaryElements aux,
              boolean meanOnly)
                throws OrekitException

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

Throws:

OrekitException - if some specific error occurs

initializeStep

public void initializeStep(AuxiliaryElements aux)
                    throws OrekitException

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

Throws:

OrekitException - if some specific error occurs

getMeanElementRate

public double[] getMeanElementRate(SpacecraftState spacecraftState)
                            throws OrekitException

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

Throws:

OrekitException - if some specific error occurs

getShortPeriodicVariations

public double[] getShortPeriodicVariations(AbsoluteDate date,
                                  double[] meanElements)
                                    throws OrekitException

Computes the short periodic variations.

Specified by:

getShortPeriodicVariations in interface DSSTForceModel

Parameters:

date - current date

meanElements - mean elements at current date

Returns:

the short periodic variations

Throws:

OrekitException - if some specific error occurs

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

computeShortPeriodicsCoefficients

public void computeShortPeriodicsCoefficients(SpacecraftState state)
                                       throws OrekitException

Compute the coefficients used for short periodic variations.

Specified by:

computeShortPeriodicsCoefficients in interface DSSTForceModel

Parameters:

state - current state information: date, kinematics, attitude

Throws:

OrekitException - if some specific error occurs

resetShortPeriodicsCoefficients

public void resetShortPeriodicsCoefficients()

Reset the coefficients used for short periodic variations.

This method is aimed to reset short periodics coefficients. It is called when one goes from a interpolation step to the next one.

Specified by:

resetShortPeriodicsCoefficients in interface DSSTForceModel

getProvider

public UnnormalizedSphericalHarmonicsProvider getProvider()

Get the spherical harmonics provider.

Returns:

the spherical harmonics provider

registerAttitudeProvider

public void registerAttitudeProvider(AttitudeProvider provider)

Register an attitude provider.

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

Specified by:

registerAttitudeProvider in interface DSSTForceModel

Parameters:

provider - the AttitudeProvider