Procedure

     JYEAR ( Seconds per julian year )

     DOUBLE PRECISION FUNCTION JYEAR ()

Abstract

     Return the number of seconds in a julian year.

Required_Reading

     None.

Keywords

     CONSTANTS

Declarations

    None.

Brief_I/O

     The function returns the number of seconds per julian year.

Detailed_Input

     None.

Detailed_Output

     The function returns the number of seconds per julian year.

Parameters

     None.

Exceptions

     Error free.

Files

     None.

Particulars

     The julian year is often used as a fundamental unit of time when
     dealing with ephemeris data. For this reason its value in terms of
     ephemeris seconds is recorded in this function.

Examples

     Suppose you wish to compute the number of julian centuries
     that have elapsed since the ephemeris epoch J1950 (beginning
     of the julian year 1950) at a particular ET epoch. The
     following line of code will do the trick.


        CENTRY = ( ET - UNITIM ( J1950(), 'JED', 'ET' ) )
       .       / ( 100.0D0 * JYEAR() )

Restrictions

     None.

Literature_References

     [1]  P. Kenneth Seidelmann (Ed.), "Explanatory Supplement to the
          Astronomical Almanac," Page 8, University Science Books,
          1992.

Author_and_Institution

     J. Diaz del Rio    (ODC Space)
     W.L. Taber         (JPL)

Version

    SPICELIB Version 1.0.1, 08-APR-2021 (JDR)

        Edited the header to comply with NAIF standard.

    SPICELIB Version 1.0.0, 13-JUL-1993 (WLT)