1. Flag CH0 in TVFLG on galaxy with calibration applied. This will look for any extremely high points that cover a lot of the line channels.
  2. Copy flag table to the line data (TABED)
  3. WIPER on the line data to look for extremely high points (> 50 Jy). Use CLIP to flag these high points. Flagging in WIPER is inefficient and writes way too many flags.
  4. Once all of the high points are gone, use WIPER to look for bad baselines/times/line channels (amp v. time). If you identify any bad baselines, you can use SPFLG to flag the specific time and baseline. Just remember to set antenna= and baseline=.
  5. TASAV to save the tables before SPLIT.
  6. SPLIT the data off. (doband 1, docalib 1)
  7. POSSM - get the spectrum (aparm(1) = 1, nplots = 0, solint =0, codetype 'real'). The real part should average to 0 in the line-free channels. Write down the channels that have your line. You will need them for continuum subtraction.
  8. UVLSF - continuum subtraction. Typical inputs are order 1, dooutput 1, channel maxchan/2, ichansel 1 50 1 1 150 200 1 1.
  9. CVEL - this will be the same inputs for ALL observations of a single galaxy.
    • aparm(1) = velocity from spreadsheet in m/s (spreadsheet is in km/s)
    • aparm(2) =nchannels/
    • aparm(3) = 1 (heliocentric)
    • aparm(4) = 0 (optical?)
    • aparm(5)~ 1420.4E6, 5752
    • aparm(7) =1 (vla data)
  10. DBCON - you will have to run this a few times to concatenate all the files
    • getn b
    • get2n c
    • outname 'bc'
    • go dbcon
    • getn bc
    • getn d1
    • outname bcd1
    • go dbcon
    • getn bcd1
    • getn d2
    • outname bcd
    • go dbcon
This final DBCON file will be what you image.

-- AdrienneStilp - 2009-03-03

This topic: Main > TWikiUsers > JuergenOtt > VlaAngst > DataReduction > Pre-ImagingSteps
Topic revision: 2009-03-03, AdrienneStilp
This site is powered by FoswikiCopyright © by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding NRAO Public Wiki? Send feedback