I've been working on bandpass calibrating some WSRT data. Usually this is a pretty simple process, but for some reason I can't get it to work out here. When I calibrate the data I'm getting large closure errors that seem to be baseline and polarization dependent. Before bandpass calibration, I went through the data and flagged anything that looked like it had an amplitude that was off. After flagging I thought the data looked pretty good in SPFLG. Changing the reference antenna or the calibration source doesn't fix the problem. What had partially fixed the problem for the LL feed at least was going from the default SOLTYPE to SOLTYPE='L1R', which uses a more robust method of fitting the bandpass that is less sensitive to variations in the input data.
Any ideas? I've put my inputs to BPASS and some sample output below.
Update (2/4/08): It looks like using bpassprm(5) = -1 instead of bpassprm(5) = 0 works. bpassprm(5) = -1 is only supposed to be used in cases of decent phase stability. It averages over time and then averages the ichansel channels rather than averaging the ichansel channels on a record-by-record base as does bpassprm(5)=0. Therefore, bpassprm(5)=-1 gives me a bit more signal enabling better bandpass calibration. The phase stability of my observations is pretty good, so I think I'm safe using this parameter.]AIPS 1: BPASS Task to generate a "Bandpass" (BP) table.
AIPS 1: Adverbs Values Comments
AIPS 1: ----------------------------------------------------------------
AIPS 1: USERID 0 User number
AIPS 1: INNAME 'POLANG' Input UV file name (name)
AIPS 1: INCLASS '13CM' Input UV file name (class)
AIPS 1: INSEQ 3 Input UV file name (seq. #)
AIPS 1: INDISK 2 Input UV file disk unit #
AIPS 1:
AIPS 1: Data Selection
AIPS 1: CALSOUR '3C286' Bandpass calibrator sources.
AIPS 1: *rest ' '
AIPS 1: QUAL -1 Calibrator qualifier -1=>all
AIPS 1: CALCODE ' ' Calibrator code ' '=>all
AIPS 1: UVRANG 0 0 UV range to select
AIPS 1: TIMERANG *all 0 Time range to select
AIPS 1: SELBAND -1 Bandwidth to select (kHz)
AIPS 1: SELFREQ -1 Frequency to select (MHz)
AIPS 1: FREQID 1 Freq. ID to select.
AIPS 1: BIF 0 Lowest IF number 0=>all
AIPS 1: EIF 0 Highest IF number 0=>all
AIPS 1: SUBARRAY 0 Subarray, 0=>all
AIPS 1: ANTENNAS *all 0 Antennas to select
AIPS 1:
AIPS 1: CLEAN map (optional)
AIPS 1: IN2NAME ' ' Cleaned map name (name)
AIPS 1: IN2CLASS ' ' Cleaned map name (class)
AIPS 1: IN2SEQ 0 Cleaned map name (seq. #)
AIPS 1: IN2DISK 0 Cleaned map disk unit #
AIPS 1: INVERS -1 CC file version #.
AIPS 1: NCOMP *all 0 # comps to use for model.
AIPS 1: 1 value per field
AIPS 1: FLUX 0 Lowest CC component used.
AIPS 1: NMAPS 0 No. Clean map files
AIPS 1: CMETHOD ' ' Modeling method:
AIPS 1: 'DFT','GRID',' '
AIPS 1: SMODEL *all 0 Source model, 1=flux,2=x,3=y
AIPS 1: See HELP SMODEL for details.
AIPS 1:
AIPS 1: Control options
AIPS 1: DOCALIB 1 > 0 calibrate data & weights
AIPS 1: > 99 do NOT calibrate weights
AIPS 1: GAINUSE 2 CL table to apply (SN table
AIPS 1: to apply to single-source)
AIPS 1: DOPOL -1 If >0 correct polarization.
AIPS 1: BLVER -1 BL table to apply.
AIPS 1: FLAGVER 1 Flag table version
AIPS 1: DOBAND -1 If >0 apply bandpass cal.
AIPS 1: Method used depends on value
AIPS 1: of DOBAND (see HELP file).
AIPS 1: BPVER 0 Bandpass table version
AIPS 1: SOLINT 0 Solution interval (mins)
AIPS 1: -1 => do whole time range
AIPS 1: SOLTYPE 'L1R' Soln type,' ','L1','GCON',
AIPS 1: REFANT 5 Reference antenna
AIPS 1: OUTVERS 0 Output BP table version
AIPS 1: 0 => a new table to be
AIPS 1: generated.
AIPS 1: SMOOTH *all 0 Smoothing function.
AIPS 1: BE VERY CAREFUL HERE.
AIPS 1: ANTWT *all 0 Ant. wts (0 => 1.)
AIPS 1: WEIGHTIT 0 Modify data weights function
AIPS 1: MINAMPER 10 Amplitude closure error
AIPS 1: regarded as excessive in %
AIPS 1: MINPHSER 10 Phase closure error regarded
AIPS 1: as excessive in degrees
AIPS 1: BPASSPRM 0 2 Control information:
AIPS 1: 0 0 1: if > 0 use only the
AIPS 1: 0 10 autocorrelation data.
AIPS 1: 10 1 2: print level - see help
AIPS 1: 1 3 3: If > 0 do not divide data
AIPS 1: 0 by source model
AIPS 1: 4: If > 0 store phases only
AIPS 1: in the BP table.
AIPS 1: 5: Divide by 'channel 0'
AIPS 1: **** SEE HELP - NEW ****
AIPS 1: 6: amp closure error limit -
AIPS 1: print channels averaging
AIPS 1: over this if (2) > 0
AIPS 1: 7: phase closure error limit
AIPS 1: print channels averaging
AIPS 1: over this if (2) > 0
AIPS 1: 8: > 0 => scalar average
AIPS 1: 9: > 0 => interpolate over
AIPS 1: flagged channels if poss.
AIPS 1: 10:1 => normalize amplitudes
AIPS 1: using all channels
AIPS 1: 2 => normalize amplitudes
AIPS 1: using ICHANSEL channels
AIPS 1: 3 => normalize amplitudes
AIPS 1: and zero average phase
AIPS 1: using ICHANSEL channels
AIPS 1: 4 => normalize amplitudes
AIPS 1: and zero average phase
AIPS 1: using all channels
AIPS 1: 0 => no deliberate norm.
AIPS 1: 11: > 0 solution weights are
AIPS 1: independent of channel
AIPS 1: = -1 weights scaled
AIPS 1: by amplitude**2
AIPS 1: < -1.5 weights scaled by
AIPS 1: 1 / amplitude**2
AIPS 1: ICHANSEL 5 50 Array of start and stop chan
AIPS 1: 1 1 numbers, plus a channel
AIPS 1: 5 50 increment and IF to be used
AIPS 1: 1 2 to select channels to sum to
AIPS 1: 5 50 find a 'channel 0'. If all
AIPS 1: 1 3 0, range set to inner 75% of
AIPS 1: 5 50 observing band.
AIPS 1: 1 4 5 50
AIPS 1: 1 5 5 50
AIPS 1: 1 6 5 50
AIPS 1: 1 7 5 50
AIPS 1: 1 8 *rest 0
AIPS 1: SPECINDX 0 Spectral index to correct
AIPS 1: 'Channel 0' uv-data
AIPS 1: IN3NAME ' ' Channel 0 uv name (name)
AIPS 1: must be '' to suppress option
AIPS 1: IN3CLASS ' ' Channel 0 uv name (class)
AIPS 1: must be '' to suppress option
AIPS 1: IN3SEQ 0 Channel 0 uv name (seq. #)
AIPS 1: IN3DISK 0 Channel 0 uv disk unit #
AIPS 1: BADDISK *all 0 Disks to avoid for scratch
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 1 Rpol
localh> BPASS1: 1- 2 25% 0d 1- 10 123% 0d 1- 13 44% 1d
localh> BPASS1: 1- 14 32% 1d 2- 4 34% 1d 2- 6 73% 178d
localh> BPASS1: 2- 7 25% 2d 2- 8 133% 0d 2- 9 238% 180d
localh> BPASS1: 2- 10 917% 178d 2- 11 662% 2d 2- 12 298% 178d
localh> BPASS1: 2- 13 80% 0d 2- 14 118% 1d 3- 8 53% 0d
localh> BPASS1: 3- 10 13% 1d 3- 13 20% 0d 3- 14 27% 0d
localh> BPASS1: 4- 6 74% 0d 4- 8 20% 2d 4- 9 63% 1d
localh> BPASS1: 4- 10 120% 178d 4- 11 31% 0d 4- 12 52% 0d
localh> BPASS1: 4- 13 35% 1d 4- 14 52% 1d 5- 8 63% 1d
localh> BPASS1: 5- 13 19% 0d 5- 14 28% 0d 6- 7 28% 1d
localh> BPASS1: 6- 9 111% 1d 6- 10 906% 0d 6- 11 84% 1d
localh> BPASS1: 6- 12 126% 1d 6- 14 24% 2d 7- 8 243% 2d
localh> BPASS1: 7- 9 26% 0d 7- 10 167% 0d 8- 11 140% 176d
localh> BPASS1: 8- 12 19% 178d 8- 13 32% 2d 8- 14 51% 2d
localh> BPASS1: 9- 10 801% 0d 9- 11 72% 0d 9- 12 107% 1d
localh> BPASS1: 9- 14 18% 2d 10- 11 586% 1d 10- 12 864% 0d
localh> BPASS1: 10- 13 205% 0d 10- 14 60% 176d 11- 12 64% 1d
localh> BPASS1: 12- 13 11% 0d 12- 14 28% 0d
localh> BPASS1: Closure error statistics: IF 7 correlator 1
localh> BPASS1: Channel Mean amp & amp**2 Mean phase & phase**2 Excess
localh> BPASS1: 1 52.84 104.74 16.72 53.59 53
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 2 Rpol
localh> BPASS1: 1- 13 13% 0d 2- 8 19% 2d 2- 13 13% 7d
localh> BPASS1: 2- 14 21% 5d 4- 8 11% 1d 4- 13 11% 2d
localh> BPASS1: 4- 14 16% 0d 5- 14 10% 1d 6- 12 12% 0d
localh> BPASS1: 7- 10 11% 1d 8- 12 1% 11d 9- 12 12% 1d
localh> BPASS1: 10- 12 12% 3d 10- 14 13% 1d
localh> BPASS1: 2 4.90 6.60 2.13 3.30 14
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 3 Rpol
localh> BPASS1: 6- 10 13% 0d 6- 14 11% 1d 9- 10 13% 1d
localh> BPASS1: 3 2.66 4.15 0.58 0.78 3
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 4 Rpol
localh> BPASS1: 6- 10 11% 0d 6- 14 11% 1d 9- 14 10% 2d
localh> BPASS1: 10- 13 12% 1d
localh> BPASS1: 4 2.66 4.08 0.57 0.76 4
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 5 Rpol
localh> BPASS1: 6- 10 11% 0d 6- 14 10% 1d 10- 13 12% 1d
localh> BPASS1: 5 2.60 3.99 0.53 0.69 3
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 6 Rpol
localh> BPASS1: 6- 7 10% 0d 6- 10 11% 0d 6- 14 12% 1d
localh> BPASS1: 9- 14 11% 2d 10- 13 12% 1d
localh> BPASS1: 6 2.65 4.10 0.55 0.73 5
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 7 Rpol
localh> BPASS1: 6- 7 10% 1d 6- 14 12% 1d 10- 13 12% 1d
localh> BPASS1: 7 2.58 3.92 0.51 0.69 3
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 8 Rpol
localh> BPASS1: 10- 13 10% 1d
localh> BPASS1: 8 2.20 3.30 0.55 0.73 1
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 9 Rpol
localh> BPASS1: 6- 7 11% 1d 10- 13 11% 1d
localh> BPASS1: 9 2.24 3.37 0.51 0.68 2
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 35 Rpol
localh> BPASS1: 6- 14 11% 1d
localh> BPASS1: 35 2.27 3.37 0.56 0.75 1
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 36 Rpol
localh> BPASS1: 6- 14 11% 1d
localh> BPASS1: 36 2.23 3.38 0.55 0.74 1
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 37 Rpol
localh> BPASS1: 6- 14 12% 1d
localh> BPASS1: 37 2.28 3.46 0.52 0.71 1
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 38 Rpol
localh> BPASS1: 6- 7 11% 0d 6- 14 12% 1d
localh> BPASS1: 38 2.32 3.58 0.54 0.73 2
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 39 Rpol
localh> BPASS1: 6- 7 10% 1d 6- 14 11% 1d
localh> BPASS1: 39 2.31 3.52 0.54 0.73 2
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 40 Rpol
localh> BPASS1: 6- 7 11% 0d 6- 14 11% 1d
localh> BPASS1: 40 2.28 3.49 0.54 0.73 2
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 41 Rpol
localh> BPASS1: 6- 7 11% 1d 6- 14 11% 1d 9- 10 10% 0d
localh> BPASS1: 10- 13 12% 1d
localh> BPASS1: 41 2.47 3.78 0.52 0.70 4
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 42 Rpol
localh> BPASS1: 6- 10 11% 0d 6- 14 10% 1d 7- 14 13% 1d
localh> BPASS1: 10- 13 12% 1d
localh> BPASS1: 42 2.79 4.24 0.54 0.73 4
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 43 Rpol
localh> BPASS1: 6- 7 10% 1d 7- 10 15% 0d 7- 14 13% 1d
localh> BPASS1: 9- 10 11% 1d 10- 13 10% 1d
localh> BPASS1: 43 2.85 4.38 0.55 0.75 5
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 44 Rpol
localh> BPASS1: 6- 14 10% 1d 7- 14 13% 1d 9- 10 10% 1d
localh> BPASS1: 10- 13 10% 1d
localh> BPASS1: 44 2.57 3.94 0.56 0.76 4
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 45 Rpol
localh> BPASS1: 6- 7 11% 1d 6- 14 11% 1d 7- 14 12% 1d
localh> BPASS1: 9- 10 10% 0d 9- 14 10% 2d 10- 13 10% 1d
localh> BPASS1: 45 2.57 3.97 0.54 0.74 6
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 46 Rpol
localh> BPASS1: 6- 7 10% 1d 6- 14 11% 1d 7- 14 12% 1d
localh> LOGFILE FOR USER 333 GETTING LARGE: USE PRTMSG AND CLRMSG NOW!
localh> BPASS1: 46 2.52 3.87 0.56 0.77 3
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 47 Rpol
localh> BPASS1: 6- 14 11% 1d 7- 14 13% 1d 9- 10 10% 0d
localh> BPASS1: 47 2.67 4.04 0.58 0.76 3
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 48 Rpol
localh> BPASS1: 6- 14 11% 1d 10- 13 11% 1d
localh> BPASS1: 48 2.58 3.86 0.57 0.76 2
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 49 Rpol
localh> BPASS1: 6- 14 10% 1d 10- 13 12% 1d
localh> BPASS1: 49 2.59 3.87 0.55 0.72 2
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 50 Rpol
localh> BPASS1: 6- 14 11% 1d 9- 10 10% 0d 10- 13 12% 1d
localh> BPASS1: 50 2.59 3.88 0.56 0.73 3
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 51 Rpol
localh> BPASS1: 9- 10 10% 0d
localh> BPASS1: 51 2.27 3.41 0.52 0.70 1
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 52 Rpol
localh> BPASS1: 9- 10 10% 0d 9- 14 10% 2d
localh> BPASS1: 52 2.07 3.11 0.52 0.69 2
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 62 Rpol
localh> BPASS1: 8- 11 11% 0d 8- 14 12% 1d 9- 14 10% 0d
localh> BPASS1: 10- 13 14% 2d
localh> BPASS1: 62 2.98 4.31 0.88 1.11 4
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 63 Rpol
localh> BPASS1: 1- 12 11% 3d 2- 4 15% 4d 2- 12 10% 8d
localh> BPASS1: 3- 7 13% 1d 4- 7 7% 12d 4- 8 19% 10d
localh> BPASS1: 4- 11 14% 5d 5- 11 10% 3d 5- 12 11% 1d
localh> BPASS1: 7- 11 11% 7d 7- 12 16% 4d 8- 12 16% 3d
localh> BPASS1: 8- 13 14% 4d 8- 14 18% 2d 10- 13 13% 5d
localh> BPASS1: 10- 14 13% 6d 11- 13 12% 3d 11- 14 12% 1d
localh> BPASS1: 63 6.02 7.44 3.66 4.36 18
localh> BPASS1: Closure errors at 3/ 2 47 50. IF/Chn no. 7 64 Rpol
localh> BPASS1: 1- 7 23% 2d 1- 8 35% 12d 1- 11 2% 12d
localh> BPASS1: 1- 12 17% 8d 1- 13 2% 11d 1- 14 2% 15d
localh> BPASS1: 2- 3 14% 5d 2- 4 63% 8d 2- 6 16% 12d
localh> BPASS1: 2- 7 203% 27d 2- 8 156% 14d 2- 10 15% 7d
localh> BPASS1: 2- 11 4% 55d 2- 12 107% 48d 2- 13 34% 45d
localh> BPASS1: 2- 14 3% 56d 3- 7 28% 4d 3- 8 41% 12d
localh> BPASS1: 3- 11 6% 12d 3- 12 9% 13d 3- 14 4% 13d
localh> BPASS1: 4- 7 73% 35d 4- 8 68% 28d 4- 10 5% 10d
localh> BPASS1: 4- 11 53% 23d 4- 12 5% 46d 4- 13 64% 2d
localh> BPASS1: 4- 14 66% 20d 5- 6 10% 2d 5- 7 11% 17d
localh> BPASS1: 5- 8 2% 21d 5- 11 27% 4d 5- 12 30% 1d
localh> BPASS1: 5- 13 16% 9d 5- 14 30% 8d 6- 7 6% 19d
localh> BPASS1: 6- 8 27% 26d 6- 11 19% 9d 6- 12 34% 7d
localh> BPASS1: 6- 14 27% 6d 7- 8 178% 15d 7- 9 15% 16d
localh> BPASS1: 7- 10 12% 11d 7- 11 125% 45d 7- 12 257% 31d
localh> BPASS1: 7- 13 50% 47d 7- 14 88% 43d 8- 9 11% 22d
localh> BPASS1: 8- 10 22% 21d 8- 11 55% 55d 8- 12 164% 42d
localh> BPASS1: 8- 13 17% 56d 8- 14 9% 53d 9- 11 5% 12d
localh> BPASS1: 9- 12 27% 3d 9- 13 4% 13d 9- 14 3% 15d
localh> BPASS1: 10- 11 10% 14d 10- 12 20% 9d 10- 13 12% 9d
localh> BPASS1: 10- 14 20% 13d 11- 12 128% 20d 11- 13 72% 6d
localh> BPASS1: 11- 14 90% 1d 12- 13 96% 23d 12- 14 106% 16d
localh> BPASS1: 13- 14 47% 6d
localh> BPASS1: 64 27.85 45.82 15.40 21.64 67
localh> BPASS1: Antenna 1 IF 7 corr 1 had 12 excess closure errors
localh> BPASS1: Antenna 2 IF 7 corr 1 had 26 excess closure errors
localh> BPASS1: Antenna 3 IF 7 corr 1 had 11 excess closure errors
localh> BPASS1: Antenna 4 IF 7 corr 1 had 24 excess closure errors
localh> BPASS1: Antenna 5 IF 7 corr 1 had 13 excess closure errors
localh> BPASS1: Antenna 6 IF 7 corr 1 had 51 excess closure errors
localh> BPASS1: Antenna 7 IF 7 corr 1 had 40 excess closure errors
localh> BPASS1: Antenna 8 IF 7 corr 1 had 31 excess closure errors
localh> BPASS1: Antenna 9 IF 7 corr 1 had 29 excess closure errors
localh> BPASS1: Antenna 10 IF 7 corr 1 had 54 excess closure errors
localh> BPASS1: Antenna 11 IF 7 corr 1 had 26 excess closure errors
localh> BPASS1: Antenna 12 IF 7 corr 1 had 31 excess closure errors
localh> BPASS1: Antenna 13 IF 7 corr 1 had 40 excess closure errors
localh> BPASS1: Antenna 14 IF 7 corr 1 had 62 excess closure errors
Monday, February 4, 2008
Bandpass calibration trauma
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