seeingLogger - NAOMI Seeing Logging Utility

     seeingLogger [-h] [-d dirname] [-DataServer <host>] [-v] [-i
     seconds] &

     seeingLogger is a daemon program that is used to create see-
     ing  trace  files based on seeing information extracted from
     the NAOMI process monitor. The each  line  detailed  in  the
     trace  file consists of a timestamp and an estimation of the
     corrected and uncorrected seeing.

     The seeingLogger will continually update the file at  inter-
     vals  specified  by  the  user on the command line or at the
     default interval of 5 seconds.

     A new seeing trace file will be created at midday everyday.

     The command  line  options  that  the  program  accepts  are
     detailed below.

     -h   Print usage information about the application.

     -d <dirname>
          Specify the name of  the  directory  within  which  the
          trace  files  will  be  written.  By default, the trace
          files are written to the directory /wht/var/seeingLogs.

     -v   Display the version number of the application.

     -DataServer <host name>
          This is the name of the machine  which  hosts  the  EPM
          data  server.  The  EPM  data  server  is the WHT OCS's
          interface to the NAOMI system and needs to  be  running
          in  order  for the application to retrieve seeing trace
          information from the AO system.

          Instruct the seeing logger to create a saw  tooth  wave
          in  the  plot file rather than taking the data from the
          NAOMI EPM. This is for test purposes.

     -i <seconds>
          Specifies the interval in seconds between  taking  sam-
          ples  of the seeing estimates and writing them into the
          file. The default interval is five seconds.

     The trace files will be written into the directory specified
     on  the  command  line  using the -d option. By default, the
     files    will    be    written    into     the     directory

     The files will adopt the following naming convention.


     Where YYYY is the current year, MM is the current month  and
     DD is the current day.

     The trace files will take the following format :

     #Trace Seeing Log Format 1.0

     963831603 0.204990 0.882917

     963831608 0.214990 0.822917

     The first line of the file is a marker so that  any  utility
     that  uses  the file can identify the file as a seeing trace
     file and can establish the version of the file format (given
     at the end of the first line).

     The second and subsequent lines will consist of the  follow-
     ing fields each separated by a TAB character.

     Time of Sample
          This is the Unix time expressed in seconds since 1st of
          January 1970.

     Corrected Seeing Estimate
          This is the corrected seeing estimate  expressed  as  a
          real number and in arcsecs.

     Uncorrected Seeing Estimate
          This is the uncorrected seeing estimate expressed as  a
          real number and in arcsecs.

          A new trace file will be created by the application  at

     The application respects the following environment variables

          This is the name of the machine which  is  hosting  the
          EPM  data  server. This may be overridden by specifying
          the name of the host machine when starting the applica-
          tion using the -DataServer command line switch.

     The following errors can be exhibited by the application :

     Unable to create seeing trace log
          If the application is unable to create the  new  seeing
          file  then  it  will abort. This will occur if the user
          that has started the application does adequate  permis-
          sion  to  write to the directory within which the trace
          files are to be written.

     Communications error with EPM
          If the application is unable  to  retrieve  the  seeing
          data  from  the  Electra process monitor it will report
          the error but will be unable to update the seeing  log.
          The application will continually retry until it finally
          resumes communication. If this error is reported, check
          to  see if the Electra process monitor is actually run-


     Craige Bevil (

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