February, 2012

Data files

When running, the WFS software deposits files in /mmt/shwfs/datadir. A cron job cleans this directory out every morning, moving the files into an archive, as described elsewhere.

The first step in performing a WFS correction is to collect one or more images. This is done by a different GUI for each secondary or mode, and will produce one or more image files with the file extension .fits. Once the files have been collected, the next step is to perform the centroid calculations. This produces a series of files, each of which contain the results of one step in the data reduction pipeline. These are all small ascii files.

The original f9 wfs software consisted of a Tcl script and a handful of compiled C programs. Because Tcl brain-damage prevents using pipes to communicate with C programs being used in this fashion, each program writes its output to a file which is then opened and read. This is why all of these files are produced, but it can be handy for post mortem analysis once the purpose and contents of these files is understood.

Filenames for a single wfs run would be:

 manual_wfs_0000.fits
 manual_wfs_0001.fits
 manual_wfs_0001.center       
 manual_wfs_0001.dao          
 manual_wfs_0001.dao.av      
 manual_wfs_0001.dao.av.zrn 
 manual_wfs_0001.dao.reg   
 manual_wfs_0001.dao.sub.zrn
 manual_wfs_0001.psf
 manual_wfs_0001.seeing
or
 auto_wfs_0000.fits
 auto_wfs_0001.fits
 auto_wfs_0002.fits
 auto_wfs_0002_ave.fits
 auto_wfs_0002_ave.center       - single line, 2 values (center coordinates)
 auto_wfs_0002_ave.dao          - 139 spot coordinates
 auto_wfs_0002_ave.dao.av       - 139 spot coordinates
 auto_wfs_0002_ave.dao.av.zrn   - 19 lines, zernicke coefficients
 auto_wfs_0002_ave.dao.reg   	- region file for DS9 with 139 spot locations
 auto_wfs_0002_ave.dao.sub.zrn  - 19 zernicke coefficients
 auto_wfs_0002_ave.psf		- IRAF PSF file for the 139 spots
 auto_wfs_0002_ave.seeing	- one line, 2 numbers (rms and seeing)