[daip] Urgent: Error using AIPS task 'DBCON'

[Alex Adair]

Hello,

AIPS (version 31DEC07) is currently installed on a Scientific Linux 
server at my workplace.  I am attempting to concatenate two UV datasets 
using the 'DBCON' task; the concatenation is "successful" in that AIPS 
does not return any errors, but the resulting combined UV dataset is not 
as expected.  I have created a plot of both the individual datasets as 
well as the combined dataset using UVPLT.  The combined plot shows 
strange structure that does not come from either of the individual 
dataset plots; many points extend up to an amplitude of ~3.5Jy while the 
individual data sets have the majority of points below 2.0Jy, and there 
are no points between 0-0.25Jy at 9-10MegaWavlngth on the combined plot, 
while they do exist on one of the individual plots.  Further 
discrepancies appear when the data is imaged using IMAGR.

I am using DBCON with REWEIGHT=0, DOPOS=1, and DOARRAY=-1 to combine two 
sets of A+ array data from the VLA.  I am also using UVPLT with XINC=1 
so that should be showing every point in the UVPLTs.  If you could 
please help, the data files are available at 
http://corral.ism.ucalgary.ca/~difrance/data/vla .  Both the FITS files 
for IRAS4.A1 and IRAS4.A2 are there (as well as their history files, if 
that helps).  The file that I have concatenated is also there 
(IRAS4.A1A2.FITS).  It was created on an AIPS installation on Mac OS X 
10 (Darwin), but the file was transfered and plotted on the Scientific 
Linux machine.

Thank you for your help,
Alex Adair
Student Research Assistant
National Research Council - Herzberg Institute of Astrophysics
Victoria, BC, Canada