fr.cnes.sirius.patrius.forces.gravity

Class BalminoGravityModel

java.lang.Object

fr.cnes.sirius.patrius.forces.gravity.AbstractGravityModel

fr.cnes.sirius.patrius.forces.gravity.AbstractHarmonicGravityModel

fr.cnes.sirius.patrius.forces.gravity.BalminoGravityModel

All Implemented Interfaces:

GravityModel, Serializable

public class BalminoGravityModel
extends AbstractHarmonicGravityModel

Computation of central body attraction with normalized coefficients and Helmholtz Polynomials.

The algorithm implemented in this class has been designed by Balmino Georges (Observatoire Midi-Pyrénées/ Groupe de Recherche de Géodésie Spatiale (GRGS) / Centre National d’Etudes Spatiales (CNES), France) in his 1990 paper: Non-singular formulation of the gravity vector and gravity gradient tensor in spherical harmonics. (Manuscr. Geod., Vol. 15, No. 1, p. 11 - 16, 02/1990). It uses normalized C and S coefficients for greater accuracy.

Warning: using a 0x0 Earth potential model is equivalent to a simple Newtonian attraction. However computation times will be much slower since this case is not particularized and hence conversion from body frame (often ITRF) to integration frame is necessary.

Since:

2.1

Version:

$Id: BalminoAttractionModel.java 18094 2017-10-02 17:18:57Z bignon $

Author:

Rami Houdroge

See Also:

Serialized Form

Concurrency :

not thread-safe, uses internal mutable attributes

Field Summary

Fields

Modifier and Type	Field and Description
static String	RADIUS Parameter name for equatorial radius.

Fields inherited from class fr.cnes.sirius.patrius.forces.gravity.AbstractGravityModel

bodyFrame, centralTermContribution, MU, paramMu

Constructor Summary

Constructors

Constructor and Description
BalminoGravityModel(Frame frame, double ae, double mu, double[][] cCoefs, double[][] sCoefs) Create an instance of a normalized gravity computation model using normalized coefficients.
BalminoGravityModel(Frame frame, double ae, double mu, double[][] cCoefs, double[][] sCoefs, int degreePD, int orderPD) Create an instance of a normalized gravity computation model using normalized coefficients.
BalminoGravityModel(Frame frame, Parameter ae, Parameter mu, double[][] cCoefs, double[][] sCoefs) Create an instance of a normalized gravity computation model using normalized coefficients.
BalminoGravityModel(Frame frame, Parameter ae, Parameter mu, double[][] cCoefs, double[][] sCoefs, int degreePD, int orderPD) Create an instance of a normalized gravity computation model using normalized coefficients.
BalminoGravityModel(Frame frame, Parameter ae, Parameter mu, double[][] cCoefs, double[][] sCoefs, int degreePD, int orderPD, boolean centralTermContributionIn) Create an instance of a normalized gravity computation model using normalized coefficients.

Method Summary

Modifier and Type	Method and Description
void	checkData(AbsoluteDate start, AbsoluteDate end) This methods throws an exception if the user did not provide all the required data to perform model call on provided range [start; end].
Vector3D	computeNonCentralTermsAcceleration(Vector3D pos, AbsoluteDate date, Transform bodyFrameToPositionFrame) Compute the acceleration due to the non-central terms of the gravitational attraction.
double[][]	computeNonCentralTermsDAccDPos(Vector3D pos, Frame frame, AbsoluteDate date) Compute acceleration derivatives with respect to the state parameters for the non-central terms.
double	getAe() Get the equatorial radius.
double[][]	getC()
double[][]	getS()
void	setAe(double aeIn) Set the equatorial radius.

Methods inherited from class fr.cnes.sirius.patrius.forces.gravity.AbstractHarmonicGravityModel

computeAcceleration, computeCentralTermAcceleration, computeCentralTermDAccDPos, computeDAccDPos, isCentralTermContributionApplied, setCentralTermContribution

Methods inherited from class fr.cnes.sirius.patrius.forces.gravity.AbstractGravityModel

getBodyFrame, getMu, setMu

Methods inherited from class java.lang.Object

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

Field Detail

RADIUS

public static final String RADIUS

Parameter name for equatorial radius.

See Also:

Constant Field Values

Constructor Detail

BalminoGravityModel

public BalminoGravityModel(Frame frame,
                           double ae,
                           double mu,
                           double[][] cCoefs,
                           double[][] sCoefs)

Create an instance of a normalized gravity computation model using normalized coefficients.

Parameters:

frame - central body frame

ae - equatorial radius constant

mu - standard gravitational constant

cCoefs - Normalized c coefficients

sCoefs - Normalized s coefficients

BalminoGravityModel

public BalminoGravityModel(Frame frame,
                           double ae,
                           double mu,
                           double[][] cCoefs,
                           double[][] sCoefs,
                           int degreePD,
                           int orderPD)

Create an instance of a normalized gravity computation model using normalized coefficients.

Parameters:

frame - central body frame

ae - equatorial radius constant

mu - standard gravitational constant

cCoefs - Normalized c coefficients for acceleration computation

sCoefs - Normalized s coefficients for acceleration computation

degreePD - degree for partial derivatives

orderPD - order for partial derivatives

BalminoGravityModel

public BalminoGravityModel(Frame frame,
                           Parameter ae,
                           Parameter mu,
                           double[][] cCoefs,
                           double[][] sCoefs)

Create an instance of a normalized gravity computation model using normalized coefficients.

Parameters:

frame - central body frame

ae - parameter storing equatorial radius

mu - parameter storing standard gravitational

cCoefs - Normalized c coefficients

sCoefs - Normalized s coefficients

BalminoGravityModel

public BalminoGravityModel(Frame frame,
                           Parameter ae,
                           Parameter mu,
                           double[][] cCoefs,
                           double[][] sCoefs,
                           int degreePD,
                           int orderPD)

Create an instance of a normalized gravity computation model using normalized coefficients.

Parameters:

frame - central body frame

ae - parameter storing equatorial radius

mu - parameter storing standard gravitational

cCoefs - Normalized c coefficients for acceleration computation

sCoefs - Normalized s coefficients for acceleration computation

degreePD - degree for partial derivatives

orderPD - order for partial derivatives

BalminoGravityModel

public BalminoGravityModel(Frame frame,
                           Parameter ae,
                           Parameter mu,
                           double[][] cCoefs,
                           double[][] sCoefs,
                           int degreePD,
                           int orderPD,
                           boolean centralTermContributionIn)

Create an instance of a normalized gravity computation model using normalized coefficients.

Parameters:

frame - central body frame

ae - parameter storing equatorial radius

mu - parameter storing standard gravitational

cCoefs - Normalized c coefficients for acceleration computation

sCoefs - Normalized s coefficients for acceleration computation

degreePD - degree for partial derivatives

orderPD - order for partial derivatives

centralTermContributionIn - true if central term contribution should be considered (by default), false if not

Method Detail

computeNonCentralTermsAcceleration

public Vector3D computeNonCentralTermsAcceleration(Vector3D pos,
                                                   AbsoluteDate date,
                                                   Transform bodyFrameToPositionFrame)
                                            throws PatriusException

Compute the acceleration due to the non-central terms of the gravitational attraction..

Specified by:

computeNonCentralTermsAcceleration in class AbstractHarmonicGravityModel

Parameters:

pos - position of the spacecraft

date - date

bodyFrameToPositionFrame - body frame to frame in which position is provided transformation (used for computation times speed-up)

Returns:

the non-central terms acceleration in the given frame

Throws:

PatriusException - if some specific error occurs

computeNonCentralTermsDAccDPos

public final double[][] computeNonCentralTermsDAccDPos(Vector3D pos,
                                                       Frame frame,
                                                       AbsoluteDate date)
                                                throws PatriusException

Compute acceleration derivatives with respect to the state parameters for the non-central terms..

Specified by:

computeNonCentralTermsDAccDPos in class AbstractHarmonicGravityModel

Parameters:

pos - position of the spacecraft

frame - frame in which the acceleration derivatives are computed

date - date

Returns:

acceleration derivatives with respect to position

Throws:

PatriusException - if derivatives cannot be computed

checkData

public void checkData(AbsoluteDate start,
                      AbsoluteDate end)
               throws PatriusException

This methods throws an exception if the user did not provide all the required data to perform model call on provided range [start; end]. It is the responsibility of the model implementation to properly throw exceptions.

Parameters:

start - range start date

end - range end date

Throws:

PatriusException - thrown if some data is missing

getAe

public double getAe()

Get the equatorial radius.

Returns:

equatorial radius (m)

setAe

public void setAe(double aeIn)

Set the equatorial radius.

Parameters:

aeIn - the equatorial radius.

getC

public double[][] getC()

Returns:

the normalized C coefficients.

getS

public double[][] getS()

Returns:

the normalized S coefficients.