Data Maintenance

Archiving
Data Reduction
Macros
Editing Files
Observer's Notes
  • General
  • Saving data from the MODCOMP (modread)
  • Saving archived data from disk (diskread)
  • Recovering archived data from CD

    General
    Strict and consistent archiving is critical for the ultimate collection, reduction and analysis of the data. Without consistent and dedicated filing, data will be easily lost or misplaced, which will cost valuable time and effort, and generally be a royal pain.

    Within the UMIGS account are many directories, one for each of the survey galaxies (i.e. n3628 for NGC 3628, i342 for IC 342)...

    Saving data from the MODCOMP (modread)
    The data are read from the MODCOMP into files created in the FCRAO package of CLASS (see scanload in data reduction), and are named by the UT date (YYmmmDD) when the observations began, e.g.,

    Scanload automatically updates the history file with the date of the observation, the observer(s), the weather, the start and end scans, and the number of maps. The user must only update the history file by adding any additional comments. An example of a line in a history.log file is:

    This means the particular galaxy was observed Jan 10, 1999 in the 12CO line by MG and MR. The weather was bad and 2 maps were completed, starting on scan 4000 and ending on scan 5000. Get it?

    Recovering archived data from disk
    If the data are older, they may no longer be on the MODCOMP. In this case, they're most likely still on disk in the archive directory. To see this directory, type

    You will see there several files of the form YYMMDD.t.gz and YYMMDD.list, almost the format we use. Find the date of your observations, and copy that file into your galaxy directory. The *.list files say what observations (scan numbers, objects, etc.) are in the T-file (the *.t.gz files). You can use grep or more to see them. You may also use the FCRAO command disklist to see the scans in a tfile.

    After copying the file, you have to unzip the file by simply typing "gunzip filename". You'll notice the .gz extension will go away. From FCRAO, use the macro diskload just as you would scanload, only now it also wants an input file (type help diskread or see the macros).

    Recovering archived data from CD
    If the data are older still and are no longer on disk, they have been stored on CD. Mark has these CDs. You read the CD on cutthroat, and copy the T-file you want from /cdrom to the home directory of umigs on cutthroat. First you have to mount the CD drive though:

    That last period says "put it right where I am now." When you're done, unmount the drive:

    Now you can remove the disk and give it back to me or Mark. To put the T-file on fcrao in the tfiles directory, use a program called ftp.

    Log onto fcrao now and procede as with diskread above.

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