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FOT fetching

The WFC-FOT data can be retrieved both from magnetic tape and by 'ftp'
from a provider on the internet.  The FOT processing is done by using 
datafiles on disk.  This means that the data from the tape has to be 
copied onto disk before it can be used.
	
Datafiles retrieved from the internet have names ending in '.dat', 
while those copied from tape have names that end in '.fot'.  There is no 
essential difference between files named according to these two schemes.  
	
It is also possible to get the disk data in 'tar'-format.  In that case 
after 'untar'ing the data will be in either one of the two naming schemes. 
Example of untarring data from a tape device into current directory:
  >  tar -xvf /dev/rmt/0mn
Example of untarring from a 'gzip'ped tarfile:
  >  gzip -cd /disk/fotfile.tar.gz | tar xvf -

In case of '.dat' nametypes it is necessary to make symbolic linkfiles of 
the '.fot' nametypes prior to processing.  See description of 'w_vaxlink' 
script how to do this.  
Example for Observation Period 999:
  >  w_vaxlink -obsper 999 -prefix OP999 -datdir /fotdisk/wop_999
which may result in the following filenames (parly shown):
  OP999__0001.fot -> /fotdisk/wop_999/tapedirtape_000000_00_0.dat
  OP999__0002.fot -> /fotdisk/wop_999/ephemeris_000000_00_0.dat
  OP999__0003.fot -> /fotdisk/wop_999/attitude_000000_00_0.dat
  OP999__0004.fot -> /fotdisk/wop_999/obt_utc_000000_00_0.dat
  OP999__0005.fot -> /fotdisk/wop_999/w1instdirtape_000000_00_0.dat
  OP999__0006.fot -> /fotdisk/wop_999/w1obsdirtape_000000_01_n.dat
  OP999__0007.fot -> /fotdisk/wop_999/w1exconf_00999_01_n.dat
  OP999__0008.fot -> /fotdisk/wop_999/w1hkd000_00999_01_n.dat
  OP999__0009.fot -> /fotdisk/wop_999/w1eng000_00999_01_n.dat
  OP999__0010.fot -> /fotdisk/wop_999/w1dir001_00999_01_n.dat
	
Some highlevel scripts like 'w_run' automatically detect the need for making 
these links and will create them automatically.

If the data is delivered on magnetic tape in FOT format it is necessary to 
load the tapefiles onto disk by using script 'w_proc'.  
For example:
  >  w_proc -fot -f OP999 -d /fotdisk/wop_999
	  
Although the FOT_ID (OP999) and the name of the directory (wop_999) can 
be freely chosen, it is advised to use the shown naming as some high level 
simple-to-use scripts assume this convention so they can be driven by only 
entering the OP-number (999 here).



Mark Savenije
Sat Jan 18 15:04:49 MET 1997