Package org.orekit.forces.gravity.potential

Class GravityFieldFactory

java.lang.Object

org.orekit.forces.gravity.potential.GravityFieldFactory

public class GravityFieldFactory
extends Object

Factory used to read gravity field files in several supported formats.

Author:

Fabien Maussion, Pascal Parraud, Luc Maisonobe

Field Summary

Fields

Modifier and Type	Field	Description
static final String	EGM_FILENAME	Default regular expression for EGM files.
static final String	FES_CHAT_EPSILON_FILENAME	Default regular expression for FES C hat and epsilon tides files.
static final String	FES_CNM_SNM_FILENAME	Default regular expression for FES Cnm, Snm tides files.
static final String	FES_HF_FILENAME	Default regular expression for FES Hf tides files.
static final String	GRGS_FILENAME	Default regular expression for GRGS files.
static final String	ICGEM_FILENAME	Default regular expression for ICGEM files.
static final String	SHA_FILENAME	Default regular expression for SHA files.
static final String	SHM_FILENAME	Default regular expression for SHM files.

Method Summary

Modifier and Type	Method	Description
static void	addDefaultOceanTidesReaders()	Add the default READERS for ocean tides.
static void	addDefaultPotentialCoefficientsReaders()	Add the default readers for gravity fields.
static void	addOceanTidesReader(OceanTidesReader reader)	Add a reader for ocean tides.
static void	addPotentialCoefficientsReader(PotentialCoefficientsReader reader)	Add a reader for gravity fields.
static void	clearOceanTidesReaders()	Clear ocean tides readers.
static void	clearPotentialCoefficientsReaders()	Clear gravity field readers.
static void	configureOceanLoadDeformationCoefficients(OceanLoadDeformationCoefficients oldc)	Configure ocean load deformation coefficients.
static NormalizedSphericalHarmonicsProvider	getConstantNormalizedProvider(int degree, int order, AbsoluteDate freezingDate)	Get the constant gravity field coefficients provider from the first supported file.
static UnnormalizedSphericalHarmonicsProvider	getConstantUnnormalizedProvider(int degree, int order, AbsoluteDate freezingDate)	Get the constant gravity field coefficients provider from the first supported file.
static LazyLoadedGravityFields	getGravityFields()	Get the instance of GravityFields that is called by the static methods of this class.
static NormalizedSphericalHarmonicsProvider	getNormalizedProvider(double ae, double mu, TideSystem tideSystem, double[][] normalizedC, double[][] normalizedS)	Create a time-independent NormalizedSphericalHarmonicsProvider from canonical coefficients.
static NormalizedSphericalHarmonicsProvider	getNormalizedProvider(int degree, int order)	Get the gravity field coefficients provider from the first supported file.
static NormalizedSphericalHarmonicsProvider	getNormalizedProvider(UnnormalizedSphericalHarmonicsProvider unnormalized)	Create a NormalizedSphericalHarmonicsProvider from an UnnormalizedSphericalHarmonicsProvider.
static OceanLoadDeformationCoefficients	getOceanLoadDeformationCoefficients()	Get the configured ocean load deformation coefficients.
static List<OceanTidesWave>	getOceanTidesWaves(int degree, int order)	Get the ocean tides waves from the first supported file.
static double[][]	getUnnormalizationFactors(int degree, int order)	Get a un-normalization factors array.
static UnnormalizedSphericalHarmonicsProvider	getUnnormalizedProvider(double ae, double mu, TideSystem tideSystem, double[][] unnormalizedC, double[][] unnormalizedS)	Create a time-independent UnnormalizedSphericalHarmonicsProvider from canonical coefficients.
static UnnormalizedSphericalHarmonicsProvider	getUnnormalizedProvider(int degree, int order)	Get the gravity field coefficients provider from the first supported file.
static UnnormalizedSphericalHarmonicsProvider	getUnnormalizedProvider(NormalizedSphericalHarmonicsProvider normalized)	Create an UnnormalizedSphericalHarmonicsProvider from a NormalizedSphericalHarmonicsProvider.
static PotentialCoefficientsReader	readGravityField(int maxParseDegree, int maxParseOrder)	Read a gravity field coefficients provider from the first supported file.

Methods inherited from class java.lang.Object

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

Field Details

ICGEM_FILENAME

public static final String ICGEM_FILENAME

Default regular expression for ICGEM files.

See Also:

• Constant Field Values

SHM_FILENAME

public static final String SHM_FILENAME

Default regular expression for SHM files.

See Also:

• Constant Field Values

EGM_FILENAME

public static final String EGM_FILENAME

Default regular expression for EGM files.

See Also:

• Constant Field Values

GRGS_FILENAME

public static final String GRGS_FILENAME

Default regular expression for GRGS files.

See Also:

• Constant Field Values

SHA_FILENAME

public static final String SHA_FILENAME

Default regular expression for SHA files.

See Also:

• Constant Field Values

FES_CNM_SNM_FILENAME

public static final String FES_CNM_SNM_FILENAME

Default regular expression for FES Cnm, Snm tides files.

See Also:

• Constant Field Values

FES_CHAT_EPSILON_FILENAME

public static final String FES_CHAT_EPSILON_FILENAME

Default regular expression for FES C hat and epsilon tides files.

See Also:

• Constant Field Values

FES_HF_FILENAME

public static final String FES_HF_FILENAME

Default regular expression for FES Hf tides files.

See Also:

• Constant Field Values

Method Details

getGravityFields

@DefaultDataContext
public static LazyLoadedGravityFields getGravityFields()

Get the instance of GravityFields that is called by the static methods of this class.

Returns:

the gravity fields used by this factory.

Since:

10.1

addPotentialCoefficientsReader

@DefaultDataContext
public static void addPotentialCoefficientsReader(PotentialCoefficientsReader reader)

Add a reader for gravity fields.

Parameters:

reader - custom reader to add for the gravity field

See Also:

• addDefaultPotentialCoefficientsReaders()
• clearPotentialCoefficientsReaders()

addDefaultPotentialCoefficientsReaders

@DefaultDataContext
public static void addDefaultPotentialCoefficientsReaders()

Add the default readers for gravity fields.

The default READERS supports ICGEM, SHM, EGM, GRGS and SHA formats with the default names ICGEM_FILENAME, SHM_FILENAME, EGM_FILENAME, GRGS_FILENAME, SHA_FILENAME and don't allow missing coefficients.

See Also:

• addPotentialCoefficientsReader(PotentialCoefficientsReader)
• clearPotentialCoefficientsReaders()

clearPotentialCoefficientsReaders

@DefaultDataContext
public static void clearPotentialCoefficientsReaders()

Clear gravity field readers.

See Also:

• addPotentialCoefficientsReader(PotentialCoefficientsReader)
• addDefaultPotentialCoefficientsReaders()

addOceanTidesReader

@DefaultDataContext
public static void addOceanTidesReader(OceanTidesReader reader)

Add a reader for ocean tides.

Parameters:

reader - custom reader to add for the gravity field

See Also:

• addDefaultPotentialCoefficientsReaders()
• clearPotentialCoefficientsReaders()

configureOceanLoadDeformationCoefficients

@DefaultDataContext
public static void configureOceanLoadDeformationCoefficients(OceanLoadDeformationCoefficients oldc)

Configure ocean load deformation coefficients.

Parameters:

oldc - ocean load deformation coefficients

See Also:

• getOceanLoadDeformationCoefficients()

getOceanLoadDeformationCoefficients

@DefaultDataContext
public static OceanLoadDeformationCoefficients getOceanLoadDeformationCoefficients()

Get the configured ocean load deformation coefficients.

If configureOceanLoadDeformationCoefficients has never been called, the default value will be the IERS 2010 coefficients.

Returns:

ocean load deformation coefficients

See Also:

• configureOceanLoadDeformationCoefficients(OceanLoadDeformationCoefficients)

addDefaultOceanTidesReaders

@DefaultDataContext
public static void addDefaultOceanTidesReaders()

Add the default READERS for ocean tides.

The default READERS supports files similar to the fes2004_Cnm-Snm.dat and fes2004.dat as published by IERS, using the configured ocean load deformation coefficients, which by default are the IERS 2010 coefficients, which are limited to degree 6. If higher degree coefficients are needed, the configureOceanLoadDeformationCoefficients method can be called prior to loading the ocean tides model with the high degree coefficients computed by Pascal Gégout.

WARNING: the files referenced in the published conventions have some errors. These errors have been corrected and the updated files can be found here: http://tai.bipm.org/iers/convupdt/convupdt_c6.html.

See Also:

• addPotentialCoefficientsReader(PotentialCoefficientsReader)
• clearPotentialCoefficientsReaders()
• configureOceanLoadDeformationCoefficients(OceanLoadDeformationCoefficients)
• getOceanLoadDeformationCoefficients()

clearOceanTidesReaders

@DefaultDataContext
public static void clearOceanTidesReaders()

Clear ocean tides readers.

See Also:

• addPotentialCoefficientsReader(PotentialCoefficientsReader)
• addDefaultPotentialCoefficientsReaders()

getConstantNormalizedProvider

@DefaultDataContext
public static NormalizedSphericalHarmonicsProvider getConstantNormalizedProvider(int degree,
 int order,
 AbsoluteDate freezingDate)

Get the constant gravity field coefficients provider from the first supported file.

If no PotentialCoefficientsReader has been added by calling addPotentialCoefficientsReader or if clearPotentialCoefficientsReaders has been called afterwards, the addDefaultPotentialCoefficientsReaders method will be called automatically.

Parameters:

degree - maximal degree

order - maximal order

freezingDate - freezing epoch

Returns:

a gravity field coefficients provider containing already loaded data

Since:

12.0

See Also:

• getNormalizedProvider(int, int)

getNormalizedProvider

@DefaultDataContext
public static NormalizedSphericalHarmonicsProvider getNormalizedProvider(int degree,
 int order)

Get the gravity field coefficients provider from the first supported file.

If no PotentialCoefficientsReader has been added by calling addPotentialCoefficientsReader or if clearPotentialCoefficientsReaders has been called afterwards, the addDefaultPotentialCoefficientsReaders method will be called automatically.

Parameters:

degree - maximal degree

order - maximal order

Returns:

a gravity field coefficients provider containing already loaded data

Since:

6.0

See Also:

• getConstantNormalizedProvider(int, int, AbsoluteDate)

getConstantUnnormalizedProvider

@DefaultDataContext
public static UnnormalizedSphericalHarmonicsProvider getConstantUnnormalizedProvider(int degree,
 int order,
 AbsoluteDate freezingDate)

Get the constant gravity field coefficients provider from the first supported file.

If no PotentialCoefficientsReader has been added by calling addPotentialCoefficientsReader or if clearPotentialCoefficientsReaders has been called afterwards, the addDefaultPotentialCoefficientsReaders method will be called automatically.

Parameters:

degree - maximal degree

order - maximal order

freezingDate - freezing epoch

Returns:

a gravity field coefficients provider containing already loaded data

Since:

6.0

See Also:

• getUnnormalizedProvider(int, int)

getUnnormalizedProvider

@DefaultDataContext
public static UnnormalizedSphericalHarmonicsProvider getUnnormalizedProvider(int degree,
 int order)

Get the gravity field coefficients provider from the first supported file.

If no PotentialCoefficientsReader has been added by calling addPotentialCoefficientsReader or if clearPotentialCoefficientsReaders has been called afterwards, the addDefaultPotentialCoefficientsReaders method will be called automatically.

Parameters:

degree - maximal degree

order - maximal order

Returns:

a gravity field coefficients provider containing already loaded data

Since:

6.0

See Also:

• getConstantUnnormalizedProvider(int, int, AbsoluteDate)

readGravityField

@DefaultDataContext
public static PotentialCoefficientsReader readGravityField(int maxParseDegree,
 int maxParseOrder)

Read a gravity field coefficients provider from the first supported file.

If no PotentialCoefficientsReader has been added by calling addPotentialCoefficientsReader or if clearPotentialCoefficientsReaders has been called afterwards, the addDefaultPotentialCoefficientsReaders method will be called automatically.

Parameters:

maxParseDegree - maximal degree to parse

maxParseOrder - maximal order to parse

Returns:

a reader containing already loaded data

Since:

6.0

getOceanTidesWaves

@DefaultDataContext
public static List<OceanTidesWave> getOceanTidesWaves(int degree,
 int order)

Get the ocean tides waves from the first supported file.

If no OceanTidesReader has been added by calling addOceanTidesReader or if clearOceanTidesReaders has been called afterwards, the addDefaultOceanTidesReaders method will be called automatically.

WARNING: as of 2013-11-17, there seem to be an inconsistency when loading one or the other file, for wave Sa (Doodson number 56.554) and P1 (Doodson number 163.555). The sign of the coefficients are different. We think the problem lies in the input files from IERS and not in the conversion (which works for all other waves), but cannot be sure. For this reason, ocean tides are still considered experimental at this date.

Parameters:

degree - maximal degree

order - maximal order

Returns:

list of tides waves containing already loaded data

Since:

6.1

getNormalizedProvider

public static NormalizedSphericalHarmonicsProvider getNormalizedProvider(double ae,
 double mu,
 TideSystem tideSystem,
 double[][] normalizedC,
 double[][] normalizedS)

Create a time-independent NormalizedSphericalHarmonicsProvider from canonical coefficients.

Note that contrary to the other factory method, this one does not read any data, it simply uses the provided data

Parameters:

ae - central body reference radius

mu - central body attraction coefficient

tideSystem - tide system

normalizedC - normalized tesseral-sectorial coefficients (cosine part)

normalizedS - normalized tesseral-sectorial coefficients (sine part)

Returns:

provider for normalized coefficients

Since:

6.0

getNormalizedProvider

public static NormalizedSphericalHarmonicsProvider getNormalizedProvider(UnnormalizedSphericalHarmonicsProvider unnormalized)

Create a NormalizedSphericalHarmonicsProvider from an UnnormalizedSphericalHarmonicsProvider.

Note that contrary to the other factory method, this one does not read any data, it simply uses the provided data.

Parameters:

unnormalized - provider to normalize

Returns:

provider for normalized coefficients

Since:

6.0

getUnnormalizedProvider

public static UnnormalizedSphericalHarmonicsProvider getUnnormalizedProvider(double ae,
 double mu,
 TideSystem tideSystem,
 double[][] unnormalizedC,
 double[][] unnormalizedS)

Create a time-independent UnnormalizedSphericalHarmonicsProvider from canonical coefficients.

Note that contrary to the other factory method, this one does not read any data, it simply uses the provided data

Parameters:

ae - central body reference radius

mu - central body attraction coefficient

tideSystem - tide system

unnormalizedC - un-normalized tesseral-sectorial coefficients (cosine part)

unnormalizedS - un-normalized tesseral-sectorial coefficients (sine part)

Returns:

provider for un-normalized coefficients

Since:

6.0

getUnnormalizedProvider

public static UnnormalizedSphericalHarmonicsProvider getUnnormalizedProvider(NormalizedSphericalHarmonicsProvider normalized)

Create an UnnormalizedSphericalHarmonicsProvider from a NormalizedSphericalHarmonicsProvider.

Note that contrary to the other factory method, this one does not read any data, it simply uses the provided data.

Parameters:

normalized - provider to un-normalize

Returns:

provider for un-normalized coefficients

Since:

6.0

getUnnormalizationFactors

public static double[][] getUnnormalizationFactors(int degree,
 int order)

Get a un-normalization factors array.

Un-normalized coefficients are obtained by multiplying normalized coefficients by the factors array elements.

Parameters:

degree - maximal degree

order - maximal order

Returns:

triangular un-normalization factors array

Since:

6.0