The AIPS Software Package and how to access it

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Topics Covered:

What is AIPS?

The Astronomical Image Processing System (AIPS) software package was developed at NRAO in the late 1970s. Its primary purpose is to calibrate and display radio astronomical data from the VLA, VLBA, or VLBI network. Users unfamiliar with AIPS should read the first three chapters of the AIPS Cookbook and either Chapter 4 (VLA) or Chapter 9 (VLBA/VLBI).

What Machine Should I Use?

There are seven public machines available for AIPS: RGLINUX2, RGLINUX4-7, and RTDC1-2. WREST (formerly called REST) and RGLINUX3 have been removed from the AIPS fleet. WREST now belongs to Lynn Matthews and RGLINUX3 has become a combined home directory and sofware server.

AIPS disks are not cross mounted. If your AIPS files are on RGLINUX2, for example, you must run AIPS on RGLINUX2. Tapes can be read (or written to) remotely by setting remhost in the AIPS verb MOUNT.

What's my Userid Number?

If you've done AIPS processing at NRAO and were assigned a userid number there, use the same userid number here. If not, please speak to Shoshana Rosenthal and she will assign you a number.

How do I Start AIPS?

Steps for getting into AIPS (on, say, RGLINUX2):

setenv AIPS_MSG_EMULATOR xterm aips tst (new, old) tv=local[:n]
setenv DISPLAY rglinux2:0.0 (to get AIPS TV when start AIPS)
(to get separate message window, if desired)
(to actually start up AIPS)

AIPS Versions:

AIPS Version Date Computer
TST     31DEC08     RGLINUX2,4-7, RTDC1-2
NEW 31DEC07 RGLINUX2,4-7, RTDC1-2
OLD 31DEC06 RGLINUX2,4

Notes and Caveats:

  1. Use AIPS TST, which consists of the most up-to-date AIPS software, unless you have a good reason not to.
  2. Please do not start AIPS by typing, for example: aips tst (new, old) rglinux2: A different set of commands is executed upon startup, which allow only one TV to be opened per machine. In other words, use "local" and not the machine name.
  3. The "tv=local" string tells the computer to choose the first available unix socket to start up a TV window. If the computer has lost track of how many TVs are running or has failed to delete temporary lock files, you will have to set this yourself with ":n". Try, for example, "F", "N", or "X"
  4. NRAO reports: "31DEC07 contains a significant difference from 31DEC06. The pseudo-array processor memory is obtained dynamically rather than being pre-compiled into each "AP" task. This means that each task asks for the memory needed and so should use less disk for large problems and less memory for small problems. This is a large enough change that we chose not to put it into a soon to be frozen version 31DEC06. It has been tested pretty thoroughly although some attributes have yet to be understood entirely."
  5. Very old disk files (created using a pre-April 1998 version of AIPS) can not be read by any of the AIPS versions currently installed on the R&G computers. Trying to read these files may permanently corrupt them and render them useless. Files that were processed with a pre-April 1998 version, then written to tape, are not affected.
  6. Running multiple AIPS sessions on the same machine does not speed up processing, since you will just be sharing cpu resources among your own sessions. More importantly, however, it has the potential to lead to unexpected and incorrect results, since parameter and input settings will also be shared.

Where are my AIPS Windows?

Two icons (windows) will pop up somewhere on your computer screen when you start AIPS:
  1. A TV window (look for picture of ape). This window is necessary for interactive editing and is very useful for the display of data or images at various stages of calibration . To use your TV window, set docrt=1 or dotv=1 in the appropriate AIPS tasks.
  2. A TEKSRV window, which is necessary for running tasks such as TKPL.

How do I Exit AIPS cleanly?

Please exit AIPS by typing "kleenex" instead of "exit." The former exits and gets rid of windows and temporary lock files.

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