How to write fits tapes at the JKT

Last updated Oct 99

At the end of the night (or more often if you prefer) you --- the observer --- will have to write your FITS data files (.fit) to a DAT tape on lpss10 using fitsinit and fitsout. In general you will write two tapes: one (called the D-tape or Data-tape) is forwarded by the observatory to the RGO data archive, and the other (called the C-tape or Copy-tape) is for you to take away.

For each D-tape and C-tape you'll need to initialise the tape. This process includes appending a tape number of the form JKTDnnnn or JKTCnnnn and other tape initialisation information as the first tape file. Here, nnnn is the tape number assigned to your run by your support astronomer or taken from the tape log book by the tapes in the computer area. A typical tape number is JKTD3472.

Always use the same tape number for both C and D tapes; always put the same data on the D-tape and its corresponding C-tape.

Please realize that the use of the fitsinit program on a tape that already contains data will destroy that data. Use fitsinit only once for every tape! Once you have initialized the tape, you can append data to it with as many separate sessions of the fitsout program as you like. Please avoid the situation that the 2Gb tapes become full; use a new tape when necessary.

The steps for writing data to tape are detailed below:

You open an xterm window on lpss10

You cd to the data directory from which you wish to write data files from (eg. /obsdata/jkta/19991231).

If you want to write data to a new tape, you initialize the tape using the command fitsinit. Answer the prompts as follows:

device: /dev/rmt/0n	you can use the default for the DAT on lpss10
block size: 2880	use the default
tape initials: GFM	use your own initals
volume name: JKTD3266	for example

After initializing, or when you want to append data to previously written data, you can use the command fitsout to write your files. First cd to the data directory, and answer to fitsout as follows:

device: /dev/rmt/0n	you can use the default for the DAT on lpss10
block size: 2880	use the default
run number of first file	23437 - for example
run number of last file	23489 - for example