MISSION_TIME(1)

NAME

     mission_time -  SOI epoch in various units for time indices

SYNOPSIS

     mission_time [-X] [date_time | rotation:longitude]

DESCRIPTION

     Without flags, mission_time provides the  day  number,  hour
     number, minute number, and second number relative to the SOI
     mission epoch (1993.01.01_00:00:00_TAI) containing the  time
     corresponding  to  the  argument.  It also provides the GONG
     month and day number, and the Carrington rotation number and
     approximate longitude of SOHO.  The argument can be either a
     standard date/time string or  a  combination  of  Carrington
     rotation  number  and  longitude (separated by a colon).  If
     the Carrington longitude argument is used, the time is  that
     of  the  central  meridian  crossing  of  the  longitude  as
     observed by SOHO.  If no argument is given the current  sys-
     tem time is used.  The returned string is in the form:

     3245 77880 4672855 280371338 GONG 67/13 CR 1983:272.8125

     The following flags can be used to restrict the output:


     -d|D                SOI mission-day only

     -h|H                SOI mission-hour only

     -m|M                SOI mission-minute only

     -g|G                GONG month and day number,  without  the
                         prefix GONG

     -c|C                Carrington   rotation   and   longitude,
                         without the prefix CR

EXAMPLES

FILES

     requires the soho_ephemeris

SEE ALSO

     time_index(1), sscan_time(3), meridian_crossing(3)

DIAGNOSTICS

     none

BUGS

     It is assumed that interval numbers include zero  and  nega-
     tive values.

     The  Carrington  longitude  may  be  for  Earth  for   times
     preceding the SOHO mission and times in the future.

     For Carrington longitude arguments in the range 1938:225  to
     1941:340,  the program may fail, and the results will likely
     be spurious.  1940:

AUTHOR

     Rick Bogart

HISTORY

     2001.11.19      SOI Version 5.0