AIPS release information
------------------------

The 15JAN96 version of AIPS was released. Partly due to the new GNU
licensing, the 15JUL95 version of AIPS was one of the most popular
ever, with 281 shipped copies, 230 of which electronically. First
statistics of the 15JAN96 version suggest that it may be equally
popular as its predecessor. The next version of AIPS will be 15OCT96,
after which we intend to release again every 6 months, with release
dates in April and October.


General AIPS developments
-------------------------

We concluded the rewrite of the AIPS Cookbook with the new Chapter 12:
"AIPS for the more sophisticated user". As before, the latest version
of every Cookbook Chapter is available via the World Wide Web. The
very strict compiler of the DEC Alpha uncovered a number of potential
problems, which were all fixed before they could lead to real
trouble. The meaning and functionality of the adverb SMOOTH was
changed throughout AIPS. It should be more consistent now between the
various tasks that have SMOOTH as an adverb. A critical look at AIPS
buffer usage uncovered a number of cases of inefficient buffer use. As
a result, improved buffer usage was implemented, along with a general
cleanup of buffer usage throughout AIPS. For the user this means that
many AIPS tasks will be somewhat more modest in their memory
requirements. As usual, a large number of existing and potential
problems were solved.


VLBI-related AIPS developments
------------------------------

The objectives of VLBI-related development in AIPS during this quarter
remain the maintenance of existing code used for VLBI data reduction
and the development of new software required for the VLBA and Space
VLBI. This has included the first release of an interactive
model-fitting task by C. Flatters, which is designed primarily for
orbiting VLBI data. A new algorithm implemented for polarization
self-calibration of spectral line VLBI data has been successfully used
to calibrate 43 GHz VLBA observations. In addition, pulse-calibration
of VLBA data has been improved for the case of non-contiguous IF
channels.  The first phase of an initiative to routinely test AIPS
software against simulated data has been completed. This has included
new tasks to generate simulated data and measure test compliance after
processing. The core calibration tasks are currently being included in
these standard tests. A significant number of general changes have
also been made during this quarter to improve reliability,
functionality and the documentation of VLBI support in AIPS.