Package org.orekit.bodies

Class JPLEphemeridesLoader

  • All Implemented Interfaces:
    CelestialBodyLoader
    public class JPLEphemeridesLoader
extends Object
implements CelestialBodyLoader
    Loader for JPL ephemerides binary files (DE 4xx) and similar formats (INPOP 06/08/10).

    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 [lu]nx[mp]####.ddd (or [lu]nx[mp]####.ddd.gz for gzip-compressed files) where # stands for a digit character and where ddd is an ephemeris type (typically 405 or 406).

    The loader supports files encoded in big-endian as well as in little-endian notation. Usually, big-endian files are named unx[mp]####.ddd, while little-endian files are named lnx[mp]####.ddd.

    The IMCCE ephemerides binary files are recognized thanks to their base names, which must match the pattern inpop*.dat (or inpop*.dat.gz for gzip-compressed files) where * stands for any string.

    The loader supports files encoded in big-endian as well as in little-endian notation. Usually, big-endian files contain bigendian in their names, while little-endian files contain littleendian in their names.

    The loader supports files in TDB or TCB time scales.

    Author:
    Luc Maisonobe

    • Field Detail

      • DEFAULT_DE_SUPPORTED_NAMES

        public static final String DEFAULT_DE_SUPPORTED_NAMES
        Default supported files name pattern for JPL DE files.
        See Also:
        Constant Field Values

      • DEFAULT_INPOP_SUPPORTED_NAMES

        public static final String DEFAULT_INPOP_SUPPORTED_NAMES
        Default supported files name pattern for IMCCE INPOP files.
        See Also:
        Constant Field Values

    • Constructor Detail

      • JPLEphemeridesLoader

        public JPLEphemeridesLoader​(String supportedNames,
                            JPLEphemeridesLoader.EphemerisType generateType)
        Create a loader for JPL ephemerides binary files.
        Parameters:
        supportedNames - regular expression for supported files names
        generateType - ephemeris type to generate

    • Method Detail

      • getLoadedAstronomicalUnit

        public double getLoadedAstronomicalUnit()
        Get astronomical unit.
        Returns:
        astronomical unit in meters

      • getLoadedEarthMoonMassRatio

        public double getLoadedEarthMoonMassRatio()
        Get Earth/Moon mass ratio.
        Returns:
        Earth/Moon mass ratio

      • getLoadedGravitationalCoefficient

        public double getLoadedGravitationalCoefficient​(JPLEphemeridesLoader.EphemerisType body)
        Get the gravitational coefficient of a body.
        Parameters:
        body - body for which the gravitational coefficient is requested
        Returns:
        gravitational coefficient in m³/s²

      • getLoadedConstant

        public double getLoadedConstant​(String... names)
        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.

        There are alternate names for constants since for example JPL names are different from INPOP names (Sun gravity: GMS or GM_Sun, Mars gravity: GM4 or GM_Mar...).

        Parameters:
        names - alternate names of the constant
        Returns:
        value of the constant of NaN if the constant is not defined

      • getMaxChunksDuration

        public double getMaxChunksDuration()
        Get the maximal chunks duration.
        Returns:
        chunks maximal duration in seconds