TGBT15A_915_103 - More fftshift and scale tests for incoherent modes

Goals

• I previously tried to find good values of vegas.scale for an fftshift value of 0x5555555f. The vegas.scale values were uncomfortably high, so I will try to an fftshift values of 0x55555557 and see if lower vegas.scale values will work. Will also test some new BOF files from Luke:
  • i0800x1024_x14_7_24t_095binw_2017_Jun_22_1648.bof
  • i1500x1024_x14_7_24t_095binw_2017_Jun_22_1020.bof
  • c1500x1024_x14_7_24t_095binw_2017_Jun_26_0950.bof
  • c0800x2048_x14_7_24t_095binw_2017_Jul_11_1123.bof
  • c1500x2048_x14_7_24t_095binw_2017_Jul_17_1526.bof

Details

• Session begins at 09:22
• Switched to Justin's VPM branch
• Using IncoherentFFTSHIFTTests SB
• Will use vegas.scale = 1000 as initial value for all modes
• SB submitted at 09:41
  • Scan #1 is i0800x0032
    • Levels are much too low
  • Scan #2 is i0800x0064
    • Levels are pretty much perfect
    • No apparent overflow issues
  • Scan #3 is i0800x0128
    • Levels are good
    • No apparent overflow issues
  • Scan #4 is i0800x0256
    • Levels are good
    • No apparent overflow issues
  • Scan #5 is i0800x0512
    • Levels are good
    • No apparent overflow issues
  • Scan #6 is i0800x1024
    • Levels are a little low, by maybe a factor of 5-6
    • Maybe some overflow artifacts? Tough to tell
  • Scan #7 is i0800x2048
    • Levels are much too high
    • There seem to be overflow artifacts but they are only really visible in the parts of the band with no signal
  • Scan #8 is i0800x4096
    • Levels are a little low, by maybe a factor of 5-6
    • Overflow artifacts don't seem to be an issue
  • Scan #9 is i1500x0032
    • Levels are good
    • No apparent overflow artifacts
  • Scan #10 is i1500x0064
    • Levels are good
  • Scan #11 is i1500x0128
    • Levels are high by a factor of about 3
    • No apparent overflow artifacts
  • Scan #12 is i1500x0256 * Levels are OK but could lower by about a factor of 1.5 * No apparent overflow artifacts
  • Scan #13 is i1500x0512 * Levels are are high by a factor of about 3 * No apparent overflow artifacts
  • Scan #14 is i1500x1024 * Levels are low by about a factor of 2-3 * Possibly seeing some minor overflow artifacts
  • Scan #15 is i1500x2048 * Levels are good * Possibly seeing some overflow issues
  • Scan #16 is i1500x4096 * No data
• Will try again with same fftshift value. Some scales have been changed: i0800x0032 --> 5000, i0800x1024 --> 5000, i0800x2048 --> 200, i0800x4096 --> 5000, i1500x0128 --> 300, i1500x0256 --> 700, i1500x0512 --> 300, i1500x1024 --> 2500
• SB submitted at 10:34
  • Scan #17 is i0800x0032
    • Levels look good
    • No apparent overflow artifacts
  • Scan #18 is i0800x0064
    • Levels look good
    • No apparent overflow artifacts
  • Scan #19 is i0800x0128
    • Levels look good
    • No apparent overflow artifacts
  • Scan #20 is i0800x0256
    • Levels look good
    • No apparent overflow artifacts
  • Scan #21 is i0800x0512
    • Levels look good
    • No apparent overflow artifacts
  • Scan #22 is i0800x1024
    • Levels look good
    • Starting to see possible overflow artifacts
  • Scan #23 is i0800x2048
    • Levels look good
    • Seeing overflow artifacts
  • Scan #24 is i0800x4096
    • Levels look good
    • Possibly seeing overflow artifacts
  • Scan #25 is i1500x0032
    • Levels look good
    • No apparent overflow artifacts
  • Scan #26 is i1500x0064
    • Levels look good
    • No apparent overflow artifacts
  • Scan #27 is i1500x0128
    • Levels look good
    • No apparent overflow artifacts
  • Scan #28 is i1500x0256
    • Levels look good
    • No apparent overflow artifacts
  • Scan #29 is i1500x0512
    • Levels look good
    • Seeing some overflow artifacts
  • Scan #30 is i1500x1024
    • Levels look good
    • No major overflow artifacts
  • Scan #31 is i1500x2048
    • Levels look good
    • Overflow artifacts are starting to appear in low-power parts of band
  • Scan #32 is i1500x4096
    • Levels are OK but could be a bit higher
• I'm worried about overflow issues in some of the modes. Will set fftshift to 0xaaaaaaaf and reset all vegas.scale to 1000
• SB submitted at 11:15
  • Scan #33 is i0800x0032
    • Levels are too low
  • Scan #34 is i0800x0064
    • Levels are a little low but reasonable
    • No apparent overflow artifacts
  • Scan #35 is i0800x0128
    • Levels are low by a factor of 2-3
    • No apparent overflow artifacts
  • Scan #36 is i0800x0256
    • Levels are a little low but reasonable
    • Maybe some minor overflow artifacts?
  • Scan #37 is i0800x0512
    • Levels are low by a factor of 2-3
    • No apparent overflow artifacts
  • Scan #38 is i0800x1024
    • Levels are low by a factor of 5-6
    • No obvious overflow artifacts
  • Scan #39 is i0800x2048
    • Levels are way too high by about a factor of 3-5
    • Possible overflow artifacts in low-power part of band
  • Scan #40 is i0800x4096
    • Levels are low by a factor of 5-6
    • No apparent overflow artifacts
  • Scan #41 is i1500x0032
    • Levels are low by a factor of 5
    • No apparent overflow artifacts
  • Scan #42 is i1500x0064
    • Levels are good
    • No apparent overflow artifacts
  • Scan #43 is i1500x0128
    • Levels are good
    • No apparent overflow artifacts
  • Scan #44 is i1500x0256
    • Levels are good
    • No apparent overflow artifacts
  • Scan #45 is i1500x0512
    • Levels are OK, could maybe be higher by a factor of 1.5
    • Maybe a slight hint of overflow artifacts
  • Scan #46 is i1500x1024
    • Levels could be higher by a factor of 2
    • No apparent overflow artifacts
  • Scan #47 is i1500x2048
    • Levels are too low by a factor of 10
    • No apparent overflow artifacts
  • Scan #48 is i1500x4096
    • Levels are too low by a factor of 2-3
  • Scan #49 IS i0800x0032
    • Levels are still too low
  • Scan #50 is i0800x0064
    • Levels are good
  • Scan #51 is i0800x0128
    • Levels are good
  • Scan #52 is i0800x0256
    • Levels are good
  • Scan #53 is i0800x0512
    • Levels are good
  • Scan #54 is i0800x1024
    • Levels are good
  • Scan #55 is i0800x2048
    • Levels are much too high
  • Scan #56 is i0800x4096
    • Levels are good
  • Scan #57 is i1500x0032
    • No data
  • Scan #58 is i1500x0064
    • Levels are good
  • Scan #59 is i1500x0128
    • Levels are good
  • Scan #60 is i1500x0256
    • Levels are good
  • Scan #61 is i1500x0512
    • Levels are
  • Scan #62 is i1500x1024
    • Levels are good
  • Scan #63 is i1500x2048
    • Levels could be lower by a factor of 1.5
  • Scan #64 is i1500x4096
    • Levels are good
  • Scan #65 is i0800x0032
    • Levels are still low by a factor of about 2
  • Scan #66 is i0800x2048
    • Levels are still too high
  • Scan #67 is i1500x0032
    • Levels could be a bit higher
  • Scan #68 is i1500x2048
    • Levels are good
  • Scan #69 is i0800x0032
    • Levels are still low
  • Scan #70 is i0800x2048
    • No longer saturated by still high
  • Scan #71 is i1500x0032
    • Levels look good
  • Scan #72 is i0800x2048
    • Now a bit too low. Going to vegas.scale = 500
  • Scan #73 is i0800x2048 with vegas.scale = 500
    • Still a bit high.
  • Scan #74 is i0800x2048 with vegas.scale = 300
    • Close enough
• Switching back to release branch at 14:28
• Submitted CheckMode1 and CheckMode29 SBs
  • All looks good

Conclusions

• While there seem to be some OK combinations of fftshift and vegas.scale, I'm concerned that some modes still either need too large a vegas.scale parameter or seem to be showing some overflow artifacts. WIll need to think about better ways to mitigate this.