The seeing data files are either from ZRMS measurements when we are using 
our cassegrain instruments, or direct K band imaging with WFCAM. In both 
cases the data are corrected to zenith and are for the K band (2.2 
microns). Note that WFCAM pixels are 0.4 arcsecs so that is the lower 
limit for those measurements. 

Files are either called cass_seeing_utdate.dat or 
WFCAM_seeing_cam*_utdate.dat (one file for each of the four cameras).

The columns in each cassegraing data file show

1) The UT date of the observation
2) The UT of the observation
3) The ZRMS (see http://arxiv.org/abs/astro-ph/0208448)
4) The zenith distance (radians) of the observation
5) The airmass of the observation
6) Estimated K band seeing in arcsecs corrected to zenith (ZD=0)

and the WFCAM data files show 

1) UT date of the observation
2) The UT of the observation
3) Airmass
4) Filter
5) The raw seeing using listed filter and at listed airmass
6) K band seeing corrected to zenith

Also, at 06:45 each morning, a summary file for the current year is 
updated (Cass_Summary_yyyy.dat and WFCAM_Summary_yyyy). The file format is 
the same as the individual data files but contains data for the entire 
year.

Please contact Tom Kerr at the JAC if you have questions.