a1659 sband hi ch measurements ons only

aug03 , 2003


    A1659 used standard ons to track positions in the sky for up to 100 minutes per src. The pattern was on (300 or 900 secs) followed by a 10 second cal on,off. The bandwidth was 750 khz with 1024 channels. There were over 300 scans with more than 60 separate sources. Eventually a map was to be made of the positions. The data was taken over many days with the same source in more than one file.


    The on followed by calon/caloff does not have an off position for bandpass correction/standing wave cancellation. Since the bandwidth is narrow and the lines are narrow, you can probably get away with this.  You want to convert the data to kelvins (this is galactic work) and then average all the scans for each source. The processing below does not worry about rfi or bad records. At 3.3 ghz this works...The processing strategy is:     The routines used for this processing are:

An example of the code:

  • filelist.dat An array of filenames determines which cor files to process:
  •  procdays.pro For each data file, pfcalib() is called to process all of the scans in the file. It will average each scan and then scale to kelvins. It will not average together any scans. It ouputs an idl save file for each day.
  • avgthenbaseline.pro This file will input all the daily save files, combine them into 1 large array (b_all[]). The data is then averaged over all the scans of the same source (checking that the frequencies and velocities are the same) resulting in b_allavg[]. This data array is then  baslined by source storing the baselined data in bbl[] while the actual baselines used are stored in blAr[]. The code at the end is various ways to look at the data.

  • What we end up with:

        bbl[] will hold the baslined data. 1 entry per source, blAr[] holds the baselines. usrcnm[] holds the unique source names (which are also in the headers of bbl,blar).

    Things that still need to be done:

    processing: usr/a1659/procdays.pro, doit.pro