SUMMARY_EPHEM(1)

NAME

     summary_ephem - create or update an  online  SOHO  ephemeris
     table

SYNOPSIS

     summary_ephem  [argument= value ...]

DESCRIPTION

     summary_ephem summarizes the detailed SOHO ephemeris  infor-
     mation to short time-averaged records of key quantities in a
     single appendable flat file for quick  access.   Six  binary
     quantities  are  tabulated  along  with each time: OBS_DIST,
     OBS_L0, OBS_B0, OBS_VR, OBS_VN, and  OBS_VW.   The  Sun-SOHO
     distance is in Astronomical Units, the SOHO Carrington coor-
     dinates  in  Degrees,  and  the  three  components  of   the
     heliocentric SOHO velocity in meters per second.

ARGUMENTS

     in=name             The  input  dataset  name.   The   input
                         dataset  is  expected  to  contain a CDF
                         file containing either the SOHO  defini-
                         tive  or  predictive  orbit  data.   The
                         standard DSDS location for these data is
                          prog:soho,level:cdrom,series:def_orb[mission_day]

     sumdir=name         The output directory name.   The  output
                         directory  is  expected  to  contain two
                         files:  /fIsummary/fR,  the  appendable,
                         binary  flat-file  containing the ephem-
                         eris  data,  and  /fIupdate_log/fR,   an
                         appendable text file logging changes.

EXAMPLES

     summary_ephem                     -p                     in=
     prog:soho,level:cdrom,series:def_orb[1065]           sumdir=
     ~CM/tables/ephemeris

FILES

      ~CM/tables/ephemeris  is the standard directory  where  the
     permanent ephemeris table is kept.

SEE ALSO

DIAGNOSTICS

     If the verbose flag (-v) is set,  the  ephemeris  quantities
     are  echoed  to  the  history  as they are inserted into the
     table.

BUGS

     Assumes that input data are always equally spaced from  ori-
     gin of epoch.


     Bad error recovery from case in which desired epoch precedes
     start of existing sumfile.

     No file locking.

     There is a possible problem of  misinterpretation  of  epoch
     times,  which  may  actually  be UT although labeled as TAI.
     The Carrington coordinates are the instantaneous coordinates
     of the spacecraft, not the location of solar disc center (no
     correction for time delay).

     The module seems superfluous, in that the ephemeris data are
     also kept in the DSDS; however, because the data in the DSDS
     are interpolated to  one-minute  samples  and  contain  much
     extraneous  information, their sheer volume makes it imprac-
     tical to keep them online in a table accessible from outside
     the pipeline environment.

AUTHORS

     Rick Bogart

HISTORY

     1996-10-21     SOI Version 1.7