org.orekit.bodies
Class JPLEphemeridesLoader

java.lang.Object
  org.orekit.bodies.JPLEphemeridesLoader

All Implemented Interfaces:

CelestialBodyLoader, DataLoader

public class JPLEphemeridesLoader
extends java.lang.Object
implements CelestialBodyLoader

Loader for JPL ephemerides binary files (DE 405, DE 406).

JPL ephemerides binary files contain ephemerides for all solar system planets.

The JPL ephemerides binary files are recognized thanks to their base names, which must match the pattern unx[mp]####.ddd (or unx[mp]####.ddd.gz for gzip-compressed files) where # stands for a digit character and where ddd is an ephemeris type (typically 405 or 406).

Version:

$Revision:1665 $ $Date:2008-06-11 12:12:59 +0200 (mer., 11 juin 2008) $

Author:

Luc Maisonobe

Nested Class Summary

static class

JPLEphemeridesLoader.EphemerisType List of supported ephemerides types.

Constructor Summary

JPLEphemeridesLoader(java.lang.String supportedNames, JPLEphemeridesLoader.EphemerisType generateType, AbsoluteDate centralDate)
Create a loader for JPL ephemerides binary files.

Method Summary

boolean	foundData() Check if some data have already been loaded.
static double	getAstronomicalUnit() Deprecated. as of 4.2, replaced by the non-static method getLoadedAstronomicalUnit()
static double	getConstant(java.lang.String name) Deprecated. as of 4.2, replaced by the non-static method getLoadedConstant(String)
static double	getEarthMoonMassRatio() Deprecated. as of 4.2, replaced by the non-static method getLoadedEarthMoonMassRatio()
static double	getGravitationalCoefficient(JPLEphemeridesLoader.EphemerisType body) Deprecated. as of 4.2, replaced by the non-static method getLoadedGravitationalCoefficient(EphemerisType)
double	getLoadedAstronomicalUnit() Get astronomical unit.
double	getLoadedConstant(java.lang.String name) Get a constant defined in the ephemerides headers.
double	getLoadedEarthMoonMassRatio() Get Earth/Moon mass ratio.
double	getLoadedGravitationalCoefficient(JPLEphemeridesLoader.EphemerisType body) Get the gravitational coefficient of a body.
double	getMaxChunksDuration() Get the maximal chunks duration.
java.lang.String	getSupportedNames() Get the regular expression for supported PV coordinates files names.
CelestialBody	loadCelestialBody(java.lang.String name) Load celestial body.
void	loadData(java.io.InputStream input, java.lang.String name) Load data from a stream.
boolean	stillAcceptsData() Check if the loader still accepts new data.

Methods inherited from class java.lang.Object

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

Constructor Detail

JPLEphemeridesLoader

public JPLEphemeridesLoader(java.lang.String supportedNames,
                            JPLEphemeridesLoader.EphemerisType generateType,
                            AbsoluteDate centralDate)
                     throws OrekitException

Create a loader for JPL ephemerides binary files.

If the regular expression for supported names is null or is the empty string, a default value of "^unx[mp](\\d\\d\\d\\d)\\.(?:(?:405)|(?:406))$" supporting both DE405 and DE406 ephemerides is used.

The central date is used to load only a part of an ephemeris. If it is non-null, all data within a +/-50 days range around this date will be loaded. If it is null, an arbitrary 100 days range will be loaded, this is useful to load only data from the header like astronomical unit or gravity coefficients.

Parameters:

supportedNames - regular expression for supported files names (may be null)

generateType - ephemeris type to generate

centralDate - desired central date (may be null)

Throws:

OrekitException - if the header constants cannot be read

Method Detail

loadCelestialBody

public CelestialBody loadCelestialBody(java.lang.String name)
                                throws OrekitException

Load celestial body.

Specified by:

loadCelestialBody in interface CelestialBodyLoader

Parameters:

name - name of the celestial body

Returns:

loaded celestial body

Throws:

OrekitException - if the body cannot be loaded

foundData

public boolean foundData()

Check if some data have already been loaded.

Specified by:

foundData in interface CelestialBodyLoader

Returns:

true if some data have already been loaded

getSupportedNames

public java.lang.String getSupportedNames()

Get the regular expression for supported PV coordinates files names.

Specified by:

getSupportedNames in interface CelestialBodyLoader

Returns:

regular expression for supported PV coordinates files names

getAstronomicalUnit

@Deprecated
public static double getAstronomicalUnit()
                                  throws OrekitException

Deprecated. as of 4.2, replaced by the non-static method getLoadedAstronomicalUnit()

Get astronomical unit.

This method loads its constants from the files using the default JPL names only.

Returns:

astronomical unit in meters

Throws:

OrekitException - if constants cannot be loaded

getLoadedAstronomicalUnit

public double getLoadedAstronomicalUnit()
                                 throws OrekitException

Get astronomical unit.

Returns:

astronomical unit in meters

Throws:

OrekitException - if constants cannot be loaded

getEarthMoonMassRatio

@Deprecated
public static double getEarthMoonMassRatio()
                                    throws OrekitException

Deprecated. as of 4.2, replaced by the non-static method getLoadedEarthMoonMassRatio()

Get Earth/Moon mass ratio.

This method loads its constants from the files using the default JPL names only.

Returns:

Earth/Moon mass ratio

Throws:

OrekitException - if constants cannot be loaded

getLoadedEarthMoonMassRatio

public double getLoadedEarthMoonMassRatio()
                                   throws OrekitException

Get Earth/Moon mass ratio.

Returns:

Earth/Moon mass ratio

Throws:

OrekitException - if constants cannot be loaded

getGravitationalCoefficient

@Deprecated
public static double getGravitationalCoefficient(JPLEphemeridesLoader.EphemerisType body)
                                          throws OrekitException

Deprecated. as of 4.2, replaced by the non-static method getLoadedGravitationalCoefficient(EphemerisType)

Get the gravitational coefficient of a body.

This method loads its constants from the files using the default JPL names only.

Parameters:

body - body for which the gravitational coefficient is requested

Returns:

gravitational coefficient in m³/s²

Throws:

OrekitException - if constants cannot be loaded

getLoadedGravitationalCoefficient

public double getLoadedGravitationalCoefficient(JPLEphemeridesLoader.EphemerisType body)
                                         throws OrekitException

Get the gravitational coefficient of a body.

Parameters:

body - body for which the gravitational coefficient is requested

Returns:

gravitational coefficient in m³/s²

Throws:

OrekitException - if constants cannot be loaded

getConstant

@Deprecated
public static double getConstant(java.lang.String name)
                          throws OrekitException

Deprecated. as of 4.2, replaced by the non-static method getLoadedConstant(String)

Get a constant defined in the ephemerides headers.

This method loads its constants from the files using the default JPL names only.

Note that since constants are defined in the JPL headers files, they are available as soon as one file is available, even if it doesn't match the desired central date. This is because the header must be parsed before the dates can be checked.

Parameters:

name - name of the constant

Returns:

value of the constant of NaN if the constant is not defined

Throws:

OrekitException - if constants cannot be loaded

getLoadedConstant

public double getLoadedConstant(java.lang.String name)
                         throws OrekitException

Get a constant defined in the ephemerides headers.

Note that since constants are defined in the JPL headers files, they are available as soon as one file is available, even if it doesn't match the desired central date. This is because the header must be parsed before the dates can be checked.

Parameters:

name - name of the constant

Returns:

value of the constant of NaN if the constant is not defined

Throws:

OrekitException - if constants cannot be loaded

getMaxChunksDuration

public double getMaxChunksDuration()

Get the maximal chunks duration.

Returns:

chunks maximal duration in seconds

stillAcceptsData

public boolean stillAcceptsData()

Check if the loader still accepts new data.

This method is used to speed up data loading by interrupting crawling the data sets as soon as a loader has found the data it was waiting for. For loaders that can merge data from any number of sources (for example JPL ephemerides or Earth Orientation Parameters that are split among several files), this method should always return true to make sure no data is left over.

Specified by:

stillAcceptsData in interface DataLoader

Returns:

true while the loader still accepts new data

loadData

public void loadData(java.io.InputStream input,
                     java.lang.String name)
              throws OrekitException,
                     java.io.IOException

Load data from a stream.

Specified by:

loadData in interface DataLoader

Parameters:

input - data input stream

name - name of the file (or zip entry)

Throws:

OrekitException - if some data is missing or if some loader specific error occurs

java.io.IOException - if data can't be read