gpboot NaN

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Laura
Posts: 6
Joined: Thu Aug 18, 2011 6:17 am

gpboot NaN

Post by Laura »

Hi

I've been calibrating some data, making use of the nfbin option in gpcal (using 4 bins). But when I get to the gpboot step, one of the bins gives me a NaN scaling:

-------------------------------------------------------------------------------
gpboot vis=$secondary.$freq cal=$primary.$freq

gpboot: Revision 1.0

Secondary flux density scaled by: 0.931
Frequency bin 1 scaled by : 0.923
Frequency bin 2 scaled by : 0.925
Frequency bin 3 scaled by : 0.927
Frequency bin 4 scaled by : NaN
-------------------------------------------------------------------------------

I've looked at the gpcal solutions for the secondary and the primary with gpcal, and I don't get any NaN errors. Could there be zero gains somewhere that are being divided-by?

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

Re: gpboot NaN

Post by ste616 »

Hi Laura,

I've had this problem in the past as well, and it always resulted from some poor data quality in that bin. Most of the time it was RFI or not enough unflagged channels (which is why it is usually the edge bins that fail).

However in your case I can't say anything definitive without looking at your data. If you'd like us to investigate this more, please supply a link to the data that is giving this error.
cheers
Jamie Stevens
ATCA Senior System Scientist
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