Package org.orekit.time

Interface TimeScales

All Known Implementing Classes:
AbstractTimeScales, LazyLoadedTimeScales
public interface TimeScales
A collection of TimeScales. This interface defines methods for obtaining instances of many common time scales.
Since:
10.1
Author:
Luc Maisonobe, Evan Ward
See Also:

  • Method Details

    • 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

    • getUT1

      UT1Scale getUT1(IERSConventions conventions, boolean simpleEOP)
      Get the Universal Time 1 scale.
      Parameters:
      conventions - IERS conventions for which EOP parameters will provide dUT1
      simpleEOP - if true, tidal effects are ignored when interpolating EOP
      Returns:
      Universal Time 1 scale
      See Also:

    • 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

    • getNavIC

      NavicScale getNavIC()
      Get the Navigation with Indian Constellation time scale.
      Returns:
      Navigation with Indian Constellation 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

    • getNavicEpoch

      AbsoluteDate getNavicEpoch()
      Reference epoch for NavIC weeks: 1999-08-22T00:00:00 NavIC time.
      Returns:
      NavIC 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

    • getJ2000Epoch

      AbsoluteDate getJ2000Epoch()
      J2000.0 Reference epoch: 2000-01-01T12:00:00 Terrestrial Time (not UTC).
      Returns:
      J2000 Epoch
      See Also:

    • 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:

    • 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:

    • of

      static TimeScales of(Collection<? extends OffsetModel> utcMinusTai, BiFunction<? super IERSConventions,? super TimeScales,? extends Collection<? extends EOPEntry>> eopSupplier)
      Create a set of time scales where all the data is loaded from the given functions.
      Parameters:
      utcMinusTai - offsets used to compute UTC. If the pre-1972 linear offsets are missing they will be added.
      eopSupplier - function to retrieve the EOP data. Since the EOP have to be reloaded every time a different IERSConventions is requested this function may be called multiple times. The requested conventions and the created time scales are passed as arguments. Attempting to call getUT1(IERSConventions, boolean) or getGMST(IERSConventions, boolean) on the time scales argument may result in unbounded recursion. To ignore EOP corrections this function should return an empty collection.
      Returns:
      a set of time scales based on the given data.
      See Also: