TGBT18B_502_10 - FFTSHIFT and variance tests


  • Take some incoherent search-mode data with different fftshift values to look at effect on bandpass variance


  • Previous work ended at 11:05.
  • vegas.conf was modified to have an fftshift value of 55555557. Using /users/rlynch/VPM/vegas.conf.newbof_fftshift for vegas.conf with new BOF files.
  • Ryan took control at 11:25. Set scan number to 1 and cycled VEGAS off/on
  • Submitted VPM-FFTSHIFT-Test SB at 11:27. Will take 120 seconds scans in all incoherent HBW modes.
    • Forgot to reset vegas.scale. Using a value of 5000 and resubmitting at 11:32. Also verified BOF file name and fftshift value
      • First scan is #2.
    • Levels are a little low in i0800x0032 with vegas.scale = 5000. May want to redo this one with vegas.scale = 7000
    • Levels also too low in i0800x0064 with vegas.scale = 5000. Will redo this one as well with vegas.scale = 7000
    • Levels are a little bit better in i0800x0128 with vegas.scale = 7000. Actually a little high on Bank D
    • Low again in i0800x0256 with vegas.scale = 5000. Will increase to 7000.
    • Levels look better in i0800x0512 with vegas.scale = 5000
    • Levels too low in i0800x1024 with vegas.scale = 5000. Will try again with 7000.
    • Levels OK in i0800x2048
    • Levels are a bit low in i0800x4096 with vegas.scale = 5000. Will also increase this to 7000.
    • Accidentally skipped i1500x0032
    • Levels look mostly OK in i1500x0064
    • Levels were actually a bit high in i1500x0128. Decreasing to 4000.
    • Levels OK in i1500x0256
    • Levels a bit high in i1500x0512. Decreasing to 4000.
    • Levels could be a tiny bit higher in i1500x1024. Will increase to 7000.
    • Levels a bit high in i1500x2048. Will decrease to 4000.
    • Levels could be a bit higher in i1500x4096. Will increase to 7000.
  • So, obsmode was cal. Redoing all scans with new scales where applicable in search mode. Submitting at 12:30
    • Missed checking bandpass for i0800x0032 rescan.
    • i0800x0064 was OK but levels could still be a bit higher. Will increase to 10000
    • i0800x0128 looks OK
    • i0800x0256 could also be a bit higher. Will increase to 10000
    • i0800x0512 looks OK
    • i0800x1024 could also be higher. Will increase to 10000
    • i0800x2048 looks OK.
    • i0800x4096 could be a bit higher but might be OK. Could increase to 10000
    • i1500x0032 looks OK
    • i1500x0064 could be a bit higher. Could increase to 7000. But probably not necessary.
    • i1500x0128 looks OK
    • i1500x0256 levels could be a bit higher. Could increase to 7000, but probably not necessary
    • i1500x0512 looks OK
    • i1500x1024 looks OK
    • i1500x2048 looks OK
    • i1500x4096 looks OK
  • Going to wrap up at 13:05 to let other high priority work to go ahead.
  • Switched vegas.conf back to release


  • Got data. Will analyze.
-- RyanLynch - 2019-02-07
Topic revision: r1 - 2019-02-14, RyanLynch
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