Invert Error:No visibilities to map

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Elagali
Posts: 4
Joined: Wed Jun 29, 2016 4:36 pm

Invert Error:No visibilities to map

Post by Elagali »

Hi there,

I am using miriad to reduce ATCA data. I have data from 3 ATCA different configurations (H214,750B,1.5B). I managed to reduce the data and the HI-spectra of my source looks perfect :-), low noise and prominent HI emission line. When I ran invert to get a map from my visibilities, I only mange to get a map for the H214.
Running the same task (similar values for all the parameters) on the 750B and the 1.5B data sets result in the following error:
invert: Revision 1.22, 2016/01/20 03:03:49 UTC
Reading the visibility data ...
Making cubes with 100 planes
Visibilities accepted: 0
### Warning: Visibilities rejected: 37140
### Fatal Error: No visibilities to map

could someone please tell me what went wrong here or some tips to solve this?

Much appreciated!
ste616
Site Admin
Posts: 220
Joined: Thu Feb 04, 2010 3:27 pm
Location: Paul Wild Observatory Narrabri NSW

Re: Invert Error:No visibilities to map

Post by ste616 »

The most common reason for this behaviour is setting invert's "slop" parameter too low. By default, invert requires that all channels in the visibility are good, or else the visibility will be rejected. I recommend that you set "slop=0.5" to see if this solves your problem.
cheers
Jamie Stevens
ATCA Senior System Scientist
Elagali
Posts: 4
Joined: Wed Jun 29, 2016 4:36 pm

Re: Invert Error:No visibilities to map

Post by Elagali »

Hello Jamie,

Thank you very much, setting the slop=0.5 solve my problem.

Cheers,

Ahmed Elagali
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