La Silla - Science Operation Department

Handling data generated by ToO observations with WFI

Doc. No. LSO-PRO-ESO-90100-XXXX, Version: 1.0 2004-12-15 F. Selman

At the telescope:

  • You will usually need to obtain observations of objects such as SNs. These can be placed in a single chip. The best is to place them in chip2 (#51 or a) as it is a good chip cosmetically, and has good efficiency. Also, standard star observation are routinelly carried out with many stars in this chip. Some Landolt fields have stars only on this chip, e.g. TPhe and RU149.

    On machine w2p2off:

  • As user astro create a subdirectory of /data/reduced/WFI to put all the data, DATADIR, e.g. wfi_Hildegar_2004-12-13 for observations for PI Hildegar taken the night of 2004-12-13.
  • In DATADIR create subdirectories with the date of the observations. For example, if the main ToO was observed during 2004-12-23, but you have flat fields taken in 2004-12-22, then create two subdirectories: 2004-12-22, and 2004-12-23
  • Create soft links of all the relevant data files to these subdirectories: bias, dome flats, sky flats, standard stars observations in the same filters, and the ToO observations. In the example above you would be creating links from /data/raw/2004-12-22 and /data/raw/2004-12-23. For example, if the files to link are images 60 to 67 you would issue the command
    ln -s /data/raw/2004-12-23/WFI_Ima.6[0-7].fits.
    which will create 8 soft links which you should verify with the command ls -l. Do this will all the files that need to be split to be sent to the archive.
  • To reduce the size of the image we should extract the chip that contains the object. To do this we use fitsTranslate. In the directory where the extraction will be carried out create a file, wfi.ftt (fits translation table), with the single line:
    Then from the command line issue the command
     fitsTranslate -v 1 -ftt wfi.ftt WFI*.fits
    This creates 8 files for each input file. For example, if there was a file named WFI_Ima.12.fits, now we will have eight additional files named WFI_Ima.12_0001.fits up to WFI_Ima.12_0002.fits.
  • Remove all the files that are not useful. For example, if the ToO is in chip 2 (#51), then you will leave only files called WFI*_0002.fits.
  • Create a log of the observations by issuing the command
     dfits WFI*.fits | fitsort OBJECT EXPTIME INS.FILT1.NAME TEL.AIRM.START > obslog 
  • Now compress all the files that will be uploaded:
     gzip WFI*.fits 
    Be patient as this takes some time
  • Repeat the above steps for each of the directories with data associated to a single ToO observation.
  • From the directory DATADIR connect to
     ncftp -u ls-too0X 
    Then create a subdirectory with the appropriate name, eg wfi_PINAME_2004-12-23, and move into that directory.
  • Download all the files, e.g. put -R 2004-12-22 2004-12-23

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