Reducing

Reducing Ceduna data on ares!!

Please note that ARES is not the fastest ever machine, so if you are doing a lot of reduction it may be quicker to install the software on your own pc. For help doing this give me a shout (Jay).

After transferring data to ares the data needs to be mauled into shape.

First log on to ares, either as yourself or as observer. Check the reduction packages libraries are hapopy by typing: cedred The output should be:
Usage: cedred ##### #####
Where ##### are start and stop times (eg 09282)

If you get a complaint about llmmin.so.0 check your LD_LIBRARY_INCLUDE contains /usr/local/lib (or get someone to update ldconf)

Assuming this all looks happy:

  1. Go to the data directory /data/jayb/Ceduna/data/
    cd /data/jayb/Ceduna/data/
    You can either work in here or copy the data you want to reduce to your own directory.
    Note: Please don't work in tpac as this is a backup.
  2. Run cedred on the range you are adding, for example:
    cedred 10147 10161

    This is the main reduction software, it does pointing and gain elevation corrections, calculates the amplitudes, merges the 4 scan blocks into one, and spits out two files (one for each IF) for each source. Arguments are yydoy so year, and day of year.

    North and south group remain separate so it is possible to have up to 4 files per source.

  3. Have a look at an example output for a source:
    ls 1144*.dat
    1144-379_IF_1_N.dat 1144-379_IF_2_N.dat
    1144-379_IF_1_S.dat 1144-379_IF_2_S.dat


  1. Next up is calibration. Please note that two different programs are used depending on if you are calibrating the north/south group or the AGN group (due to the different cadence of obs) here we will describe the north/south group calibration. To do the AGN group just run cedcal_agn instead of cedcal.

    cedcal must be run for each source and group separately but only on IF_1! It will do the second IF automatically:
    cedcal 1144-379_IF_1_S.dat
    Have a quick look at the output to make sure the numbers look reasonable.

    If you have both north and south group data for one source (1144 for example) running:
    cedcal 1144-379_IF_1_N.dat
    Will now merge all the data into the output files:
    1144-379_IF_1_cal.dat and 1144-379_IF_2_cal.dat

You now have calilbrated ceduna data! It is usually a good idea to apply some averaging to the data. This can be done using cedav.
Simply run:
cedav 1144-379_IF_1_cal.dat
Cedav will create two new files: 1144-379_IF_1_cal.dat.av and 1144-379_IF_2_cal.dat.av I recommend concatinating this with previous reductions for the same source and keeping that file somewhere specific.