org.orekit.forces.empirical

Class HarmonicAccelerationModel

java.lang.Object

org.orekit.forces.empirical.HarmonicAccelerationModel

All Implemented Interfaces:

AccelerationModel

public class HarmonicAccelerationModel
extends Object
implements AccelerationModel

Harmonic acceleration model.

Since:

10.3

Author:

Luc Maisonobe, Bryan Cazabonne

Constructor Summary

Constructors

Constructor and Description
HarmonicAccelerationModel(String prefix, AbsoluteDate referenceDate, double fundamentalPeriod, int harmonicMultiplier) Simple constructor.

Method Summary

Modifier and Type	Method and Description
List<ParameterDriver>	getParametersDrivers() Get the drivers for acceleration model parameters.
void	init(SpacecraftState initialState, AbsoluteDate target) Initialize the acceleration model at the start of the propagation.
<T extends CalculusFieldElement<T>> T	signedAmplitude(FieldSpacecraftState<T> state, T[] parameters) Compute the signed amplitude of the acceleration.
double	signedAmplitude(SpacecraftState state, double[] parameters) Compute the signed amplitude of the acceleration.

Methods inherited from class java.lang.Object

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

Constructor Detail

HarmonicAccelerationModel

public HarmonicAccelerationModel(String prefix,
                                 AbsoluteDate referenceDate,
                                 double fundamentalPeriod,
                                 int harmonicMultiplier)

Simple constructor.

Parameters:

prefix - prefix to use for parameter drivers

referenceDate - reference date for computing polynomials, if null the reference date will be automatically set at propagation start

fundamentalPeriod - fundamental period (typically set to initial orbit Keplerian period)

harmonicMultiplier - multiplier to compute harmonic period from fundamental period)

Method Detail

init

public void init(SpacecraftState initialState,
                 AbsoluteDate target)

Initialize the acceleration model at the start of the propagation.

The default implementation of this method does nothing

Specified by:

init in interface AccelerationModel

Parameters:

initialState - spacecraft state at the start of propagation.

target - date of propagation. Not equal to initialState.getDate().

signedAmplitude

public double signedAmplitude(SpacecraftState state,
                              double[] parameters)

Compute the signed amplitude of the acceleration.

The acceleration is the direction multiplied by the signed amplitude. So if signed amplitude is negative, the acceleratin is towards the opposite of the direction specified at construction.

Specified by:

signedAmplitude in interface AccelerationModel

Parameters:

state - current state information: date, kinematics, attitude

parameters - values of the force model parameters

Returns:

norm of the acceleration

signedAmplitude

public <T extends CalculusFieldElement<T>> T signedAmplitude(FieldSpacecraftState<T> state,
                                                             T[] parameters)

Compute the signed amplitude of the acceleration.

The acceleration is the direction multiplied by the signed amplitude. So if signed amplitude is negative, the acceleratin is towards the opposite of the direction specified at construction.

Specified by:

signedAmplitude in interface AccelerationModel

Type Parameters:

T - type of the elements

Parameters:

state - current state information: date, kinematics, attitude

parameters - values of the force model parameters

Returns:

norm of the acceleration

getParametersDrivers

public List<ParameterDriver> getParametersDrivers()

Get the drivers for acceleration model parameters.

Specified by:

getParametersDrivers in interface AccelerationModel

Returns:

drivers for acceleration model parameters