WORKSHOP_02.md

Workshop part 2: Radio oddities

This is a work in progress.

Downloads

from part 1

mkdir -p ${outdir:-./demo/data}/1341914000/raw
curl -L -o ${outdir:-./demo/data}/1341914000/raw/1341914000_20220715095302_ch137_000.fits 'https://projects.pawsey.org.au/mwa-demo/1341914000_20220715095302_ch137_000.fits'

New

mkdir -p ${outdir:-demo/data/}1060550888/raw
curl -L -o ${outdir:-demo/data/}1060550888/raw/1060550888_20130814212851_gpubox12_01.fits 'https://projects.pawsey.org.au/birli-test/1060550888_20130814212851_gpubox12_01.fits'

SSINS

Did aoflagger really get all the RFI? you can inspect the raw, preprocessed and calibrated files using ssins.py.

export obsid=1341914000
export metafits=${outdir:-demo/data/}${obsid}/raw/${obsid}.metafits
export raw="$(ls -1 ${outdir:-demo/data/}${obsid}/raw/${obsid}*.fits)"
export cal_ms="${outdir:-demo/data/}${obsid}/cal/hyp_cal_${obsid}.ms"
python demo/04_ssins.py $metafits $raw
# examine AOFlagger flags from preprocessed uvfits: autocorrelations and cross correlations
demo/05_prep.sh
python demo/04_ssins.py --flags --autos --no-diff ${outdir:-demo/data/}${obsid}/prep/birli_${obsid}*.uvfits
python demo/04_ssins.py --flags --crosses --no-diff ${outdir:-demo/data/}${obsid}/prep/birli_${obsid}*.uvfits
# examine flagged measurement set
demo/06_cal.sh
python demo/04_ssins.py $cal_ms

1341914000 - Multiple Issues

let's look at the z-scores for each antenna's autocorrelations. To simplify the plot, we'll look at only the long baseline group A initially.

python demo/04_ssins.py ${outdir:-demo/data/}1341914000/raw/1341914000{.metafits,_20220715095302_ch137_000.fits} --suffix '.ch137.LBA' --no-diff --autos --sigchain --no-flag-init --sel-ants LBA{1..8} --sel-pols xx

let's make a note to flag LBA5 for this observation and plot the others

python demo/04_ssins.py ${outdir:-demo/data/}1341914000/raw/1341914000{.metafits,_20220715095302_ch137_000.fits} --suffix '.ch137' --no-diff --autos --sigchain --skip-ants LBA5 --sel-pols xx

Now we can see three broadband RFI events seen by almost all tiles.

Let's see if we can flag it by asking ssins to look at the autocorrelations

python demo/04_ssins.py ${outdir:-demo/data/}1341914000/raw/1341914000{.metafits,_20220715095302_ch137_000.fits} --suffix '.ch137' --autos --skip-ants LBA5 --sel-pols yy

It found the start and end of the broadband stripes, but doesn't flag the middle. Let's try cross-correlations.

python demo/04_ssins.py ${outdir:-demo/data/}1341914000/raw/1341914000{.metafits,_20220715095302_ch137_000.fits} --suffix '.ch137' --crosses --skip-ants LBA5 --sel-pols yy

It seems to have done it, but with a little bit of collateral dammage. We can also see Starlink RFI at 175MHz

1060550888 channel 143 - Tile104 Narrow Swoosh

python demo/04_ssins.py ${outdir:-demo/data/}1060550888/raw/1060550888{.metafits,_20130814212851_gpubox12_01.fits} --no-diff --autos --sigchain --suffix '.ch143' --sel-ants Tile104 --sel-pols yy

1087596040 channel 134 - 171MHz Snake

python demo/04_ssins.py ${outdir:-demo/data/}1087596040/raw/1087596040{.metafits,_20140623220027_gpubox21_00.fits} --no-diff --crosses --suffix '.ch134' --sel-pols yy

1087596040 channel 143 - Tile108 Swoosh

python demo/04_ssins.py ${outdir:-demo/data/}1087596040/raw/1087596040{.metafits,_20140623220027_gpubox12_00.fits} --suffix '.ch143' --sel-ants Tile108 --sel-pols xx

1088806248 channel 133 - Snake

python demo/04_ssins.py ${outdir:-demo/data/}1088806248/raw/1088806248{.metafits,_20140707221035_gpubox22_00.fits} --crosses --suffix '.ch133' --sel-pols xx

1088806248 channel 145 - Tile055 Discontinuity

python demo/04_ssins.py ${outdir:-demo/data/}1088806248/raw/1088806248{.metafits,_20140707221035_gpubox10_00.fits} --no-diff --autos --sigchain --suffix '.ch145' --sel-ants Tile055 --sel-pols yy

1089238040 channel 133 - Snake

python demo/04_ssins.py ${outdir:-demo/data/}1089238040/raw/1089238040{.metafits,_20140712220707_gpubox22_00.fits} --no-diff --suffix '.ch133' --sel-pols xx

1090871744 channel 137 - Slow-moving TV

python demo/04_ssins.py ${outdir:-demo/data/}1090871744/raw/1090871744{.metafits,_20140731195531_gpubox18_00.fits} --no-diff --crosses --suffix '.ch137' --sel-pols xx

todo: all-sky images

1094319712 channel 142 - Tile108 Swoosh

python demo/04_ssins.py ${outdir:-demo/data/}1094319712/raw/1094319712{.metafits,_20140909174139_gpubox13_00.fits} --no-diff --autos --sigchain --suffix '.ch142' --sel-pols xx

python demo/04_ssins.py ${outdir:-demo/data/}1094319712/raw/1094319712{.metafits,_20140909174139_gpubox13_00.fits} --no-diff --crosses --suffix '.ch142' --skip-ants Tile108 --sel-pols xx

1252516448 channel 142 - Slow-moving TV

python demo/04_ssins.py ${outdir:-demo/data/}1252516448/raw/1252516448{.metafits,_20190914171353_gpubox13_00.fits} --no-diff --autos --sigchain --suffix '.ch142' --sel-pols xx

1255099440 channel 135 - Satellite Reflection

python demo/04_ssins.py ${outdir:-demo/data/}1255099440/raw/1255099440{.metafits,_20191014144345_gpubox20_00.fits}  --no-diff --crosses --suffix '.ch135' --sel-pols xx

1261482120 channel 177 - Tile027 Sparkle

python demo/04_ssins.py ${outdir:-demo/data/}1261482120/raw/1261482120{.metafits,_20191227114144_gpubox16_00.fits}  --sigchain --no-diff --suffix '.ch177' --sel-pol xx

python demo/04_ssins.py ${outdir:-demo/data/}1261482120/raw/1261482120{.metafits,_20191227114144_gpubox16_00.fits}  --no-diff --crosses --suffix '.ch177' --skip-ants Tile027 --sel-pol yy

1324134264 channel 142 - slow TV 181-188MHz

python demo/04_ssins.py ${outdir:-demo/data/}1324134264/raw/1324134264{.metafits,_20211221150406_ch142_000.fits} --suffix '.ch142.xxyy' --sigchain --no-diff --sel-pols xx yy

python demo/04_ssins.py ${outdir:-demo/data/}1324134264/raw/1324134264{.metafits,_20211221150406_ch142_000.fits} --suffix '.ch142.noT65E23' --crosses --no-diff --skip-ants Tile065 HexE23 --sel-pol xx

1344506888 channel 137 - Rx07 issue

python demo/04_ssins.py ${outdir:-demo/data/}1344506888/raw/1344506888{.metafits,_20220814100750_ch137_000.fits} --suffix '.ch137' --sigchain --no-diff

python demo/04_ssins.py ${outdir:-demo/data/}1344506888/raw/1344506888{.metafits,_20220814100750_ch137_000.fits} --suffix '.ch137.noRx7LBAB5' --no-dif  --crosses --skip-ants Tile07{1..8} LBA5 LBB5 --sel-pol xx

1360791928 - LB E,F,G issue

python demo/04_ssins.py ${outdir:-demo/data/}1360791928/raw/1360791928{.metafits,_20230218214510_ch137_000.fits} --suffix '.ch137' --sigchain --no-diff --sel-pol xx

python demo/04_ssins.py ${outdir:-demo/data/}1360791928/raw/1360791928{.metafits,_20230218214510_ch137_000.fits} --suffix '.ch137' --sigchain --no-diff --skip-ants LBE{1..8} --sel-pol yy

1361310560

python demo/04_ssins.py ${outdir:-demo/data/}1361310560/raw/1361310560{.metafits,_20230224214902_ch137_000.fits} --suffix '.ch137' --sigchain --no-diff --sel-pol xx

python demo/04_ssins.py ${outdir:-demo/data/}1361310560/raw/1361310560{.metafits,_20230224214902_ch137_000.fits} --suffix '.ch137.noLBE' --sigchain --no-diff --skip-ants LBE{1..8} --sel-pol xx

python demo/04_ssins.py ${outdir:-demo/data/}1361310560/raw/1361310560{.metafits,_20230224214902_ch137_000.fits} --suffix '.ch137.noLBE.noRx7_10_12' --sigchain --no-diff --skip-ants LBE{1..8} Tile07{1..8} Tile10{1..8} Tile12{1..8} --sel-pol yy

1361397000

• Tile151 issue
• Rx10 & Rx12 issue

python demo/04_ssins.py ${outdir:-demo/data/}1361397000/raw/1361397000{.metafits,_20230225214942_ch137_000.fits} --suffix '.ch137' --sigchain --no-diff

1362519024

python demo/04_ssins.py ${outdir:-demo/data/}1362519024/raw/1362519024{.metafits,_20230310213006_ch065_000.fits} --suffix '.ch065' --sigchain --no-diff --sel-pol yy