twillis449
commented
8 years ago RE: 2) above - I meant everything works fine for the first ~2500 integrations, and then the meqserver goes 'poof'!!
Open twillis449 opened 8 years ago
twillis449
commented
8 years ago RE: 2) above - I meant everything works fine for the first ~2500 integrations, and then the meqserver goes 'poof'!!
I'm having some problems getting fitting and calibration up and running for base-line dependent averaging simullations. The following stuff is available in my directory 'test_fitting' on Jake.
1) I've created a 5 min long test observation at 0.1 sec sampling rate with 99 antennas (just taking every 2nd antenna from a comination of meerkat + SKA1). The MS is already created - ska1_orig.MS. Run the turbo-sim.py script to generate a noise-free sim of a 1 Jy point source at the fieid centre whose phase is perturbed by the ionosphre. The parameters are already set in the .tdl.conf so the sim will run correctly.
2) OK - I try running calico-generic.py with the parameters given in the .tdl.conf file. Basically do a self-cal for each 0.1 sec time interval. (Note that I had to modify the standard supplied calico-generic script as the standard things like oms-gridded sky had been commented out.) Every thing works find for the first ~2500 intefrations - phase is perfectly straightened out, but then the meqserver just goes 'poof' with no proper explanation except a status of -1, so the last 500 integrations are not calibrated! I get the same exact result if I use just a complete meercat 64 antenna configuration. From looking at the output of 'top', my computer is not running out of memory etc.
3) Since calico-generic doesn't work, I try calico-stefcal.py (again modified to read in the oms-gridded-sky models). Here, stefcal seems to do some solving as a lot of stuff gets printed out on the terminal, but no calibration corrections are applied to the input data, and nothing appears in an inspector plot of the stefcal gains. I suspect that I'm not setting some flag here as I haven't used stefcal before - my current parameters are also in the .tdl.conf file. Could you please try a run and tell me what I'm not specifying correctly. Also I note that many of the stefcal parameters have no 'information' section associated with them so I don't have the slightest idea what they do.
So -- I'm stuck with the snail-like CASA gaincal and applycal routines until I can get one of these calibration schemes up and running. Advice needed!