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TGBT18B_502_01 - LBW tests round one
First round of testing of modifications to config tool and VEGAS M&C to support low bandwidth (100/200 MHz) modes.
Will test incoherent and coherent dedispersion modes
Will set up for cal and search mode scans
Where supported, will test GUPPI and VEGAS in dual backend mode
Session begins at 09:30
Joe took care of software version switch over
Ryan edited vegas.conf with a section for c0200x0064
Ryan edited scripts with legal values of tint/nchan (need to check that the config tool limits are appropriate)
Had to sort out some script typos. Nothing major.
NOTE: first few scans have a source name from last project. First scan number will be 14
Trying i0100x0512 with full Stokes parameters
The VEGAS mode isn't recognized. Script aborted.
Joe had to restart Grail
On second attempt GUPPI did not configure properly, and LO2 seemed to be tuned for VEGAS LBW group 2 instead of 3.
Joe edited vegas.conf to use group 2
VEGAS is also warning that Valon frequency is not equal to that set, although data seem tuned properly...
On third attempt GUPPI seemed to configure and data is flowing!
VEGAS levels look low (scale set to 100) but configuration seems OK. GUPPI data look OK at first glance.
Edited vegas.scale to 10000
Levels too high now, but data successfully recorded for cal and search mode, as well as with total intensity only
Noticed that VEGAS isn't balancing. Joe suggests changing the order in the Backend keyword. This has no effect.
Adding a manual balance and trying again.
Manual balance worked. Levels are a bit high with vegas.scale = 2000 in inco modes, but going to forge ahead to test other modes.
Search-mode data folded OK and cal is there. Bandpass has a strange dip in the middle, though, and there seem to be some periodic low-level artifacts to investigate.
guppi.scale is too high in i0100x1024
Cal not seen in i0100x1024.
Levels too high in GUPPI for i0100x4096. Data are zeros in VEGAS.
i0200x2048 scan aborted. Bank A had a fault in the scale_inco parameter.
It is properly set to 2000, though I notice that scale_[iquv] are not set. Not sure why the manager is complaining.
Signal only appearing in upper 50 MHz of band for i0200x4096. Input IF is tuned to 300 MHz but if we are in group 2 it should be 500 MHz.
Same thing in i0200x8192
Also not seeing cal in the part of the band where there is a bit of signal
VEGAS is not configured properly. It seems to be set up for a c0800x0064 with only one bank (A) active, instead of c0800x0512 (the c0100x0064 equivalent).
Cal is not showing up in GUPPI. GUPPI does seem to be configured correctly.
Cal is there in VEGAS although the square wave is noisy and there appear to be regular artifacts in the cal phase space
Frequency labels in VEGAS are wrong. Clearly it doesn't recognize what set-up it is in.
Bank A is active and should be getting an input IF of 250 MHz. I think this means that it should be in center of the observed band...
Same VEGAS config issue in c0100x0128. Cal is there in GUPPI this time, but only in one small part of the band...maybe it's a scaling issue?
Same VEGAS issues in c0100x0256. GUPPI no longer shows any signs of cal signal.
Same hint of cal signal in GUPPI in c0100x0512. VEGAS issues still the same.
Probably issues with vegas.scale in coherent modes, but tough to tell given set-up issues.
Same issues in 200 MHz BW modes (both VEGAS and GUPPI)
Cal signal does look stronger in VEGAS
Joe began switching back to release branch around 13:10
Did check outs and ended session at 14:00
100 MHz inco modes seemed to configure well. Other modes had some issues.
Check config tool limits on tint/nchan combinations
Make sure GUPPI configures properly every time
Fix Balance() behavior to automatically include VEGAS in dual backend mode
Look into VEGAS bandpass shape and possible artifacts
Clear up Valon warning in VEGAS
Need to do a test-tone injection to verify frequency tuning (though it seems to be OK by-eye)
Zeros in VEGAS bandpass in i0100x4096
Cal not seen in VEGAS for i0100x1024
scale_inco parameter seems to be illegal in i0200x2048
Fix coherent set up in VEGAS
Investigate artifacts in cal signal in coherent modes
Will investigate further and test again next maintenance day
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Topic revision: r2 - 2018-12-06,
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