Procedure

   SpiceDouble b1900_c ( void )

Abstract

   Return the Julian Date corresponding to Besselian Date 1900.0.

Required_Reading

   None.

Keywords

   CONSTANTS

Brief_I/O

   The function returns the Julian Date corresponding to Besselian
   date 1900.0.

Detailed_Input

   None.

Detailed_Output

   The function returns 2415020.31352, the Julian Date corresponding
   to Besselian Date 1900.0 as reported by Lieske [1].

Parameters

   None.

Exceptions

   Error free.

Files

   None.

Particulars

   Lieske [1] defines a mapping from Julian Ephemeris Date 
   to Besselian:

      BE = 1900. + (JED - 2415020.31352)/365.242198781

   The inverse mapping being:

      JED = (BE - 1900.)*365.242198781 + 2415020.31352

Examples

   The following code fragment illustrates the use of b1900_c.

      /.
      Convert Julian Date to UTC seconds past the reference
      epoch (B1900).
      ./

      spref = ( jd - b1900_c() ) * spd_c();

Restrictions

   None.

Literature_References

   [1] Jay Lieske, ``Precession Matrix Based on IAU (1976)
       System of Astronomical Constants,'' Astron. Astrophys.
       73, 282-284 (1979).

Author_and_Institution

   W.L. Taber      (JPL)
   I.M. Underwood  (JPL)

Version

   -CSPICE Version 1.1.0, 01-SEP-2005 (EDW)

       Added journal reference and associated citations.

   -CSPICE Version 1.0.1, 08-FEB-1998 (EDW)

       Corrected and clarified header entries.

   -CSPICE Version 1.0.0, 25-OCT-1997 (EDW)

Index_Entries

   besselian date 1900.0

Link to routine b1900_c source file b1900_c.c