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P737 Jan 28th 2013

Observers: G. Hobbs (SOC/Marsfield), D. Reardon (Parkes)


  • DFB search mode tests to check whether extra subints are written at the end in split mode and normal mode
  • J0437-4715 pcm track with 20cm multibeam
  • Check issues remaining in AFB-decommissioning document

Working directory: /DATA/BRAHE_1/hob044/P737/P737_28jan

Schedule: P737/P737_28Jan.sch


  • Schedule lines: 1-2. Pulsar: Vela, Observation: 120seconds, 100us tsmp, no split files, 1bit, 1prod., nsblk = 2048. Filename: s130127_174043.sf
  • Number of subintegrations: 185881 (ahh ... this has NSBLK = 1 as I was using sr4 instead of sr3 in the schedule line)
  • All subintegrations okay except for the last 7 (which have zeroes for the TSUBINT).
  • This file is 1G in size -- deleted it from my work area.
  • Update the schedule as we had sr4 parameters set instead of sr3. Do it again.
  • Updated schedule lines: 1-2. Pulsar: Vela, Observation: 120 seconds, 100us tsmp, no split files, 1bit, 1prod, nsblk = 2048. Filename: s130127_175101.sf
  • Number of subintegrations: 621
  • All subintegrations okay except for the last 7 (which have zeroes for the TSUBINT)
  • Note that 120seconds with 100us sampling does not give an integral number of NSBLK (=2048)
  • Update schedule to have an integration time of 128s.
  • Schedule: lines 3-4: same as above but with an integration time of 128s. Filename: s130127_175101.sf. Have 670 subintgrations. Same again ... last 7 subintegrations wrong.
  • Note that 7 subintegrations = 1.4336 seconds
  • Double the sample time (200us).
  • Schedule: lines 5-6: same as above, but with sample time of 200us. Filename: s130127_181356.sf
  • Have 338 subintegrations. Still have 7 incorrect subintegrations at the end.
  • In the above tests I had tsmp = 512us in the SRCH_SET, but 100us or 200us in the actual observation. Now set tsmp = 200us in srch_set and also in the main observations
  • Schedule: lines 7-8: same as above, but with sr3_tsmp 200 in the srchset line: Filename: s130127_182149.sf
  • Have 509 subintegrations! Last 7 are wrong!
  • Why do I now have more subintegrations? nsblk = 2048 in both files. tsamp = 0.0002 in both files. Requested tobs = 128s in both files. One file has length = 138.445s and the more recent has 208.486s.
  • Run again, but make the distance needed to slew between the srchset and the actual observation smaller than before.
  • Schedule: lines 9-10: (shorter slew required). Filename: s130127_182149.sf
  • Now have 363 subintegrations! What's going on? Still have TSUBINT = 0 for the last 7 subintegrations.
  • Run again, but have the srchset at exactly the same place as the pulsar (i.e., no slew required)
  • Schedule: lines 11-12: (no slew required): Filename: s130127_184009.sf
  • Now have 338 subintegrations again! Last 7 subintegrations wrong
  • Just copy lines 11-12 in the schedule again (to 13-14) and re-load the schedule by just clicking on "view" (instead of "own")
  • Schedule: lines 13-14: Filename: s130127_184555.sf
  • Identical -- 338 subintegrations. Last 7 subintegrations wrong.
  • Now try with the file splitting mode. Include sr3_ftmx 30 in the schedule
  • Schedule: lines 15-16: Filenames s130127_185339.sf, s130127_185339_1.sf, s130127_185339_2.sf, s130127_185339_3.sf, s130127_185339_4.sf
  • First 4 have 81 subintegrations (length = 33.178s) the last has 42 subintegrations (17.203s).
  • s130127_185339.sf (last 7 subintegrations wrong)
  • s130127_185339_1.sf (last 7 subintegrations wrong)
  • s130127_185339_2.sf (last 7 subintegrations wrong)
  • s130127_185339_3.sf (last 7 subintegrations wrong)
  • s130127_185339_4.sf (last 7 subintegrations)
  • Now try and ensure that all the samples/subints/number in each file are integers. Have sr3_ftmx 30. Have nsblk = 2000 (does this have to be a 2^N number?). tsamp = 200us. Have tobs = 120s. Should have 75 subints in each file and four files in total.
  • Schedule: lines 17-18. Filename: s130127_190515.sf, s130127_190515_1.sf, s130127_190515_2.sf, s130127_190515_3.sf, s130127_190515_4.sf
  • All files have 83 subintegrations except for the last one that has 17 subintegrations.
  • In all cases the last 7 subintegrations are wrong
  • Do just line number 18 again (i.e., don't redo the srchset)
  • s130127_191029.sf -> s130127_191029_4.sf
  • Results are identical to the previous test
  • All of the above tests used pfits_fv to view the subint headers. Now use "fv". Get the same result. Note all the following are set to zero

- TSUBINT, OFF_SUB, LST_SUB, RA_SUB, DEC_SUB, etc. etc., DAT_FREQ and the DATA array

  • Note that we're using atcsver next. PDFB3 Version 2012-07-10_22:28

Try again. Unfortunately Vela has set. Using 1744-1134.

  • Schedule line 19-20: 1744 (exactly the same as the previous test, but using 1744 instead). Filename: s130127_204156.sf (_1,_2,_3,_4)
  • Get same results as before (7 bad subints)
  • Schedule line 21-22: Same as before, but now with 8bit sampling and 4 pol. Filename: s130127_204906.sf (_1,_2,_3,_4)
  • Perfect!! No problems with bad subints. Either caused by NBITS or NPOL
  • Try putting NPOL back to 1. Schedule line 23-24: as above with 8bits sampling, but 1 pol. Filename: s130127_205546.sf
  • Perfect!! Still no problems. So no issue with NPOL.
  • Try putting NBITS = 4. Schedule lines 25-26: nbits = 4, npol = 1. Filename: s130127_210146.sf
  • Perfect!! Still no problems.
  • Try putting NBITS = 2. Schedule lines 27-28: nbits = 2, npol =1. Filename: s130127_210750.sf
  • Perfect!! Still no problems.
  • Re-try now with NBITS = 1. Schedule lines 29-30: nbits = 1, npol = 1. Filename: s130127_211256.sf
  • Wrong .... have last subints incorrect

Summary: the search mode works except for nbits = 1.