[daip] New Ticket - [!JOM-292297]: problem with IMERG

[Gaelle Dumas]

New Ticket: problem with IMERG

Dear Helpdesk

I am using the task IMERG in aips to combine VLA and single-dish data for short spacing correction. I used this task with success on other VLA and single-dish data but I have a problem with these data: the result merged map is very wrong: it consists of 4 times the top right quadrant of the high resolution image.  I attached the image of the combined map for illustration (IMERG_RESULT.jpg). 

I encountered this problem before and solved it by making the maps smaller, but I cannot do it this these particular maps, because the object if very extended and I already cut the maps on the edge of the outer disk.


The high and low resolution maps have the same geometry (number of pixel, pixel size, pixel ref etc...) the beams are circular and the task IMERG do not complain with an error message. Here is the message which corresponds to the combined map I've attached:
IMERG1: Create M51.20.5G   .IMERG .   2 (MA)  on disk  1  cno   53
IMERG1: QINIT: did a GET  of     14116 Kwords, OFF          2996465
IMERG1: NORM. FACTOR FOR IMAGE 2 IS: 3.60994E-06
IMERG1: IMERG HI-RES MAP = 'M51.20.5G   ' . 'HGEOM ' .    2   1
IMERG1: IMERG LO-RES MAP = 'M51_Eff2    ' . 'REMAG ' .    1   1
IMERG1: IMERG IMERG MAP  = 'M51.20.5G   ' . 'IMERG ' .    2   1
IMERG1: IMERG BLC =     1     1  /BOTTOM LEFT CORNER
IMERG1: IMERG TRC =  1900  1900  /TOP   RIGHT CORNER
IMERG1: IMERG UVMIN,UVMAX =   2.0000E-01   4.5000E-01  /OF NORM. ANNULUS
IMERG1: IMERG FACTOR =   3.6099E-06 /NORM. OF LOW RES.
IMERG1: IMERG BLC(3) =      1 /CHANNEL NUMBER
IMERG1: Appears to have ended successfully


Can you help me to solve this problem?

thanks you in advance
Gaelle Dumas

Ticket Details
===================
Ticket ID: JOM-292297
Department: AIPS Data Processing
Priority: Default
Status: Open
Link:  https://help.nrao.edu/staff/index.php?_m=tickets&_a=viewticket&ticketid=573
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