[daip] MATCH

[Andy Biggs]

Hi Eric. I've been doing some digging to shed some more light on the 
problem. I use ANBPL to display the hour angle of each data point; the 
output from MATCH is shifted by -8 hours compared to the input. I then 
modified TI2HA to print out a number of its variables. GSTIAT has changed 
after executing MATCH, by the same number of hours.

The reference date of the master file appears to lurk somewhere in the 
MATCH output where it is used by the hour angle routines. The dates of my 
master file and the file on which I run MATCH differ by almost exactly 16 
months; sidereal times separated by this amount of time differ by -8 
hours. This appears to be the cause of the problem.

Unfortunately, my AIPS programming skills are limited and I don't know 
where the hour angle routines are getting GSTIAT from. The observe date in 
the header is the correct date of observation, but as I mentioned, the 
reference date in the AN table is that of the master file. Changing this 
with TABED makes no difference to the hour angle routines.

I hope that some of this makes sense.

Andy