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Abstract
I/O
Examples
Particulars
Required Reading
Version
Index_Entries

Abstract


   CSPICE_UTC2ET converts an input time from Calendar or Julian 
   Date UTC format to ephemeris seconds past J2000.

   For important details concerning this module's function, please refer to
   the CSPICE routine utc2et_c.

I/O

   
   Given:
   
      utcstr   a scalar string containing a UTC time-date expression
               in either Calendar or Julian Date format .
               
               'utcstr' should not exceed 80 characters in length.
 
   the call:
   
      cspice_utc2et, utcstr, et
   
   returns:
   
      et   the scalar double precision value equivalent of 'utcstr', 
           expressed in ephemeris seconds past J2000. If an error occurs, 
           or if the input string is ambiguous, et is not changed.
   
      Note: NAIF recommends calls to cspice_str2et instead of cspice_utc2et.
   

Examples


   Any numerical results shown for this example may differ between
   platforms as the results depend on the SPICE kernels used as input
   and the machine specific arithmetic implementation.

   
      ;;
      ;; Load a leapseconds kernel.
      ;;
      cspice_furnsh, 'standard.tm'
   
      ;;
      ;; Set the time string.
      ;;
      utcstr = 'December 1, 2004 15:04:11'
   
      ;;
      ;; Make the call.
      ;;
      cspice_utc2et, utcstr, et
      print, et

      ;;
      ;; It's always good form to unload kernels after use,
      ;; particularly in IDL due to data persistence.
      ;;
      cspice_kclear

   IDL outputs:
   
         1.5518552e+08

Particulars


   This routine handles that task of converting strings
   representing epochs in the UTC system to ephemeris seconds
   (TDB) past the epoch of the J2000 frame.

   Although this routine is intended primarily for the
   conversion of epochs during the "space age" it may also
   be used to convert much earlier epochs.  However, before
   using this routine to convert epochs prior to 1972
   you must be sure that the assumptions made by in the
   implementation are consistent with the accuracy of
   the input calendar string.

   This routine does not attempt to account for variations in the
   length of the second that were used prior to Jan 1, 1972.
   Instead each "UTC" day prior to Jan 1, 1972 is assumed
   to have exactly 86400 TDT seconds.

Required Reading


   ICY.REQ
   TIME.REQ

Version


   -Icy Version 1.0.2, 04-NOV-2008, EDW (JPL)

      Expanded and improved header

   -Icy Version 1.0.1, 27-MAR-2006, EDW (JPL)

      Corrected a typo in the Examples section, 'time_str'
      in the cspice_utc2et replaced with 'utcstr'.

   -Icy Version 1.0.0, 16-JUN-2003, EDW (JPL)

Index_Entries


   utc to ephemeris time




Wed Apr  5 17:58:04 2017