*** QUICK CHECK FOR DATA QUALITY **

Here is a quick way to check for data integrity by checking that
all beams are present in a FITS file. Probably you should
not do this to a FITS file "in progress", but it is possible
to check on it right after it's done. This code is based
on Brian's "quicklook.pro" routine, but run line-by-line.

Check the observing log to find out the name of the
FITS file you want to examine; this can be a file which
was aborted mid-way.

Log into a fast computer at AO as "a2010".
Go to /share/a2010-2/work

In this example, we assume the errant file is:
   /share/pserverf.sdb1/wappdata/wapp.20080324.a2010.0025.fits

IDL> @wasinit2
IDL> @alfinit
IDL> file='/share/pserverf.sdb1/wappdata/wapp.20080324.a2010.0025.fits'
IDL> istat=wasopen(file, desc)
IDL> istat=corinpscan(desc, b, scan=desc.scani[0].scan)
IDL> corplot, b[30]

This displays the total power for record 31 for each beam, each pol. 
 Note that the beam designations are off by one (N+1). Are they all
 there? Is galactic HI in the right place?

Check another record (N) by changing the index in b[N-1]. Do this
repeatedly to try to find exactly when the error occurred.

IDL> corplot, b[300]
skip board:       6 data not finite
IDL> corplot, b[200]
skip board:       6 data not finite
IDL> corplot, b[100]
IDL> corplot, b[150]
skip board:       6 data not finite
IDL> corplot, b[120]
skip board:       6 data not finite
IDL> corplot, b[110]
IDL> corplot, b[115]
skip board:       6 data not finite
IDL> corplot, b[114]
skip board:       6 data not finite
IDL> corplot, b[113]

So the failure occured after record (113+1), 114 seconds into the file,
and the problem was that beam 5 dropped out entirely.
The other beams looked ok, through the rest of that drift.

If you want to see the spectrum of only one of the beams, try:
IDL > corplot, b[30], brd=1   (for Beam 0, etc)
IDL > corplot, b[30], brd=5   (for Beam 4, etc)