Interface TimeScales

    • Method Detail

      • getTAI

        TAIScale getTAI()
        Get the International Atomic Time scale.
        Returns:
        International Atomic Time scale
      • getUTC

        UTCScale getUTC()
        Get the Universal Time Coordinate scale.
        Returns:
        Universal Time Coordinate scale
      • getTT

        TTScale getTT()
        Get the Terrestrial Time scale.
        Returns:
        Terrestrial Time scale
      • getGST

        GalileoScale getGST()
        Get the Galileo System Time scale.
        Returns:
        Galileo System Time scale
      • getGLONASS

        GLONASSScale getGLONASS()
        Get the GLObal NAvigation Satellite System time scale.
        Returns:
        GLObal NAvigation Satellite System time scale
      • getQZSS

        QZSSScale getQZSS()
        Get the Quasi-Zenith Satellite System time scale.
        Returns:
        Quasi-Zenith Satellite System time scale
      • getGPS

        GPSScale getGPS()
        Get the Global Positioning System scale.
        Returns:
        Global Positioning System scale
      • getTCG

        TCGScale getTCG()
        Get the Geocentric Coordinate Time scale.
        Returns:
        Geocentric Coordinate Time scale
      • getTDB

        TDBScale getTDB()
        Get the Barycentric Dynamic Time scale.
        Returns:
        Barycentric Dynamic Time scale
      • getTCB

        TCBScale getTCB()
        Get the Barycentric Coordinate Time scale.
        Returns:
        Barycentric Coordinate Time scale
      • getGMST

        GMSTScale getGMST​(IERSConventions conventions,
                          boolean simpleEOP)
        Get the Greenwich Mean Sidereal Time scale.
        Parameters:
        conventions - IERS conventions for which EOP parameters will provide dUT1
        simpleEOP - if true, tidal effects are ignored when interpolating EOP
        Returns:
        Greenwich Mean Sidereal Time scale
        Since:
        7.0
      • getIRNSS

        IRNSSScale getIRNSS()
        Get the Indian Regional Navigation Satellite System time scale.
        Returns:
        Indian Regional Navigation Satellite System time scale
      • getBDT

        BDTScale getBDT()
        Get the BeiDou Navigation Satellite System time scale.
        Returns:
        BeiDou Navigation Satellite System time scale
      • getJulianEpoch

        AbsoluteDate getJulianEpoch()
        Reference epoch for julian dates: -4712-01-01T12:00:00 Terrestrial Time.

        Both java.util.Date and DateComponents classes follow the astronomical conventions and consider a year 0 between years -1 and +1, hence this reference date lies in year -4712 and not in year -4713 as can be seen in other documents or programs that obey a different convention (for example the convcal utility).

        Returns:
        Julian epoch.
      • getModifiedJulianEpoch

        AbsoluteDate getModifiedJulianEpoch()
        Reference epoch for modified julian dates: 1858-11-17T00:00:00 Terrestrial Time.
        Returns:
        Modified Julian Epoch
      • getFiftiesEpoch

        AbsoluteDate getFiftiesEpoch()
        Reference epoch for 1950 dates: 1950-01-01T00:00:00 Terrestrial Time.
        Returns:
        Fifties Epoch
      • getCcsdsEpoch

        AbsoluteDate getCcsdsEpoch()
        Reference epoch for CCSDS Time Code Format (CCSDS 301.0-B-4): 1958-01-01T00:00:00 International Atomic Time (not UTC).
        Returns:
        CCSDS Epoch
      • getGalileoEpoch

        AbsoluteDate getGalileoEpoch()
        Reference epoch for Galileo System Time: 1999-08-22T00:00:00 GST.
        Returns:
        Galileo Epoch
      • getGpsEpoch

        AbsoluteDate getGpsEpoch()
        Reference epoch for GPS weeks: 1980-01-06T00:00:00 GPS time.
        Returns:
        GPS Epoch
      • getQzssEpoch

        AbsoluteDate getQzssEpoch()
        Reference epoch for QZSS weeks: 1980-01-06T00:00:00 QZSS time.
        Returns:
        QZSS Epoch
      • getIrnssEpoch

        AbsoluteDate getIrnssEpoch()
        Reference epoch for IRNSS weeks: 1999-08-22T00:00:00 IRNSS time.
        Returns:
        IRNSS Epoch
      • getBeidouEpoch

        AbsoluteDate getBeidouEpoch()
        Reference epoch for BeiDou weeks: 2006-01-01T00:00:00 UTC.
        Returns:
        Beidou Epoch
      • getGlonassEpoch

        AbsoluteDate getGlonassEpoch()
        Reference epoch for GLONASS four-year interval number: 1996-01-01T00:00:00 GLONASS time.

        By convention, TGLONASS = UTC + 3 hours.

        Returns:
        GLONASS Epoch
      • getJavaEpoch

        AbsoluteDate getJavaEpoch()
        Java Reference epoch: 1970-01-01T00:00:00 Universal Time Coordinate.

        Between 1968-02-01 and 1972-01-01, UTC-TAI = 4.213 170 0s + (MJD - 39 126) x 0.002 592s. As on 1970-01-01 MJD = 40587, UTC-TAI = 8.000082s

        Returns:
        Java Epoch
      • getPastInfinity

        AbsoluteDate getPastInfinity()
        Dummy date at infinity in the past direction.
        Returns:
        the earliest date.
      • getFutureInfinity

        AbsoluteDate getFutureInfinity()
        Dummy date at infinity in the future direction.
        Returns:
        the latest date.
      • createJulianEpoch

        AbsoluteDate createJulianEpoch​(double julianEpoch)
        Build an instance corresponding to a Julian Epoch (JE).

        According to Lieske paper: Precession Matrix Based on IAU (1976) System of Astronomical Constants, Astronomy and Astrophysics, vol. 73, no. 3, Mar. 1979, p. 282-284, Julian Epoch is related to Julian Ephemeris Date as:

         JE = 2000.0 + (JED - 2451545.0) / 365.25
         

        This method reverts the formula above and computes an AbsoluteDate from the Julian Epoch.

        Parameters:
        julianEpoch - Julian epoch, like 2000.0 for defining the classical reference J2000.0
        Returns:
        a new instant
        See Also:
        getJ2000Epoch(), createBesselianEpoch(double)
      • createBesselianEpoch

        AbsoluteDate createBesselianEpoch​(double besselianEpoch)
        Build an instance corresponding to a Besselian Epoch (BE).

        According to Lieske paper: Precession Matrix Based on IAU (1976) System of Astronomical Constants, Astronomy and Astrophysics, vol. 73, no. 3, Mar. 1979, p. 282-284, Besselian Epoch is related to Julian Ephemeris Date as:

         BE = 1900.0 + (JED - 2415020.31352) / 365.242198781
         

        This method reverts the formula above and computes an AbsoluteDate from the Besselian Epoch.

        Parameters:
        besselianEpoch - Besselian epoch, like 1950 for defining the classical reference B1950.0
        Returns:
        a new instant
        See Also:
        createJulianEpoch(double)