Data Archival

*** NOTE: USERS MUST SUPPLY ALL ARCHIVAL MEDIA. ***

CCD Data

Most Sun Sparc Stations have 8mm Exabyte tape drives.

• All drives but one (in the 2.7m control room) are capable of writing in the 8200 format (2.3Gbyte/tape).
• The drives at the 2.7M and 0.8M are capable of additionally writing in the 8505 format (10 Gbyte/tape). HOWEVER, it is recommended to use only the 8200 format unless you are sure that you have a drive capable of reading the higher density formats (there are very few of them in Austin). One of the drives at the 2.7m telescope will ONLY write in high density, though it can read a low density tape if the tape is write-locked. All Suns are capable of writing your data in the FITS format, HOWEVER we suggest using TAR unless there is a specific reason that you need FITS. The TAR tapes will write in about 1/10 the amount of time it takes to write a FITS tape, with fewer problems.
• If you are using one of the "true blue" Sun 8mm drives and the top and bottom LED start to flash, don't panic! This means that the tape drive's internal counter says it needs to be cleaned. Eject your tape after you are finished with the current operation and place a cleaning cartrige in it. When it is finished cleaning itself, it will eject the cleaning tape and the LEDs will turn off. Please make sure to log the cleaning on the cleaning tape and/or on its box (cross off one of the boxes). If all of the boxes are full on log, toss the cleaning tape in the trash, note it on the night report and another cleaning tape will be provided.
• There is currently only one 4mm DAT drive available at Mt.Locke. It is located at the 2.7M and connected to Atlas (2.7M Data Collection Sun) and can be accessed either via IRAF (mtao) or TAR (/dev/rst0/dev/nrst0). (See all the tape drive designations here).
• NOTE: Some data disks are NFS mounted on all systems so you may not need to copy your data over to another machine to use its tape drive. If you would like to write your data from a non-mounted system, please call computer support for help.
• Writing data to tape. Please note that these are merely a couple of suggestions for ways to write your data. There are other procedures for both tar and IRAF writing of your data. 
• In IRAF, go to your data directory, place your tape in the drive, then type 'dataio' to enter the tape-writing package. Then 'epar wfits'. Edit the file as shown in the sample below. The FITS filename (line 2) must correspond to the particular tape drive you are using. Line 3 should be 'yes' or 'no' depending on whether your tape is blank or not. See above for all the IRAF tape drive designations.

                                   I R A F  
                    Image Reduction and Analysis Facility
PACKAGE = dataio
   TASK = wfits

iraf_fil=                *.fits  IRAF images
fits_fil=                  mtt  FITS filename(s)
newtape =                  yes  Blank tape?
(fextn  =                 fits) Extension to append to output disk FITS filename
(extensi=                   no) Write all images to a single FITS file ?
(global_=                  yes) Prepend a global header to the FITS extensions f
(make_im=                  yes) Create a FITS image file?
(long_he=                   no) Print FITS header cards?
(short_h=                  yes) Print short header?
(bitpix =                    0) FITS bits per pixel
(blockin=                    0) FITS tape blocking factor
(scale  =                  yes) Scale data?
(autosca=                  yes) Auto_scaling?
bscale  =                   1.  FITS bscale
bzero   =                   0.  FITS bzero
(mode   =                   ql)

Type 'CTRL-D' to exit the editor, then type 'wfits' to begin the transfer. When done, remove your tape from the drive and exit IRAF nicely (lo). Just exiting your windows at this point without exiting IRAF first may cause problems for the next observer.

Writing to a tar tape. This is easier, much, much faster and much less likely to hose up. From a UNIX shell, go to your data directory Place your tape in the drive.

tar cvf /dev/nrst4 .          (does not rewind the tape when done)
tar cvf /dev/rst4 .           (rewinds the tape when done)

Photometry and Polarimetry

All IBM-PCs have 3.5 inch high density floppy drives as well as a hard drive for real time storage. All QUILT data are written in ASCII format and can be copied from the hard drive to a floppy with a normal MSDOS copy command.