To:      Phyllis Jackson

From:    Eric Greisen

Date:    "1 January 1996"

Subject: Quarterly Report on AIPS (1995 Q4)

     The first release of AIPS under a "GNU General Public License"
rather than a "user agreement" took place on August 18.  The source
code and full binary forms for a variety of architectures are found
through anonymous ftp in directory aips/15JUL95 (and below) on the
computer known as baboon.cv.nrao.edu.  Since then, 154 sites have
copied some or all of AIPS to their machines.  Tape copies of AIPS are
also available, currently without a media charge. So far 51 copies
have been shipped on tape to 32 sites.  To provide more information on
AIPS use, and to provide data which will allow us to set priorities, a
registration system has been established. Although the AIPS code is
now free and mostly anonymous, help with installation and use of AIPS
requires a site "registration" which is also at no charge to
institutions engaging in research in astronomy.  To date, 70 of the
186 non-NRAO sites have registered the 15JUL95 release, indicating
that they expect to run it on 485 computers.  These include 163 Sun4,
167 Solaris, 47 PC (Linux), 39 DEC Alpha, 27 HP, 20 SGI, 13 IBM, 4 DEC
Ultrix, 2 Sun3, 2 PC (Linux Elf), and 1 Convex systems.

     The new edition of the CookBook neared completion during the
quarter.  Out-of-date chapters on analysis, advanced subjects (POPS,
remote use, programming), exiting, and the handling of problems were
revised to reflect modern conditions and capabilities.  A brand new
chapter on single-dish data in AIPS was written.  The new index plus
the table of contents and all references to these chapters were kept
current.  The only chapter that has not been modernized is the
Glossary, which is rather dated but still very useful.  All chapters
of the CookBook are made available via the World Wide Web.  Users can
fetch the new chapters as they are actually completed by fetching the
files via the WWW (or via anonymous ftp).  AIPS is at WWW URL
http://www.cv.nrao.edu/aips/.

     A number of changes of general interest were made.  When users
enter a gripe, the text is now sent by e-mail to a number of accounts.
This makes the gripe system available to non-NRAO sites and should
improve the reaction time to many of the gripes.  The remote use of
magnetic tapes and, particularly,  pseudo-tape disk files caused a
glaring hole in computer security which has been repaired at the cost
of forcing remote sites to be registered with the site providing the
remote "tape" service.  Remote users of compute servers will soon be
able to interact with their data using AIPS display tools running on
their desktop computer using a new provision for "guest" display
accounts.  A "garbage collector" has been written for POPS, the user
input language of AIPS.  This has been needed for 25 years and not
only reclaims wasted space but allows the user to pick up new system
verbs, adverbs, and procedures while retaining all adverb values and
procedures.

     Of interest both to VLA and to VLBA, the new task CPASS
determines the spectral bandpass calibration with polynomial fits
rather than channel-by-channel averages.  This should enhance the
flexibility and signal-to-noise ratios in that calibration process.
Fringe-rate imaging may now be applied to VLA data with FRMAP to find
the areas of emission prior to using more standard imaging techniques.
FITLD applies a correction for the correlator's saturation effect in
VLBA self spectra.  Serious errors in position angles plotted by PCNTR
and fit by IMFIT, JMFIT, and SAD were corrected.  The handling of
noise and error estimates in the fitting routines was also improved.

     Support for single-dish data reduction in AIPS was enhanced by a
significant number of (individually) small corrections and
improvements.  The new task SDMOD may be used to generate model
single-dish data or subtract a model from real data.  OTFUV was
corrected to read 12m on-the-fly data on all computer architectures.

File: /home/primate/egreisen/AIPS/reports/QRep95d.TXT