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AIPS++ Project News
Tim Cornwell- NRAO/Socorro
The third release of the AIPS++ package will be made on November 13 at
the ADASS meeting in Boston. This release has many new features aimed
at scientific completeness. The most notable improvement is the
ability to process VLA observations entirely in AIPS++, from VLA
archive tape to final deconvolved image. Advances have been made in
many different areas of synthesis processing:
- Filling from a vla archive tape can be performed using the
vlafiller tool.
- Flagging can be performed either interactively with visplot or
in a batch mode using flagger.
- Calibration, including both flux scale and phase determination
can be performed using the calibrater tool.
- Imaging, including many variants of deconvolution, can be performed
using the imager tool.
In addition, numerous aspects of the user interface have been
improved. We have been aided in this by a group of dedicated (and
persistent!) testers in Socorro. The testers (Debra Shepherd, Greg
Taylor, and Steve Myers) have worked closely with the AIPS++ group to
improve all areas of the processing of VLA data. There still remains
some work to be done in making the end-to-end path for VLA data as
easy to use as possible. For example, an improved chapter for
Getting Results in AIPS++
is in preparation. Another examples is that we have been experimenting
with vertical integration of the synthesis tools into one tool called
map. Improvements in these areas will be made available as patches to
the new release as they become available.
The single dish processing environment, dish, has also seen
significant improvements. Bob Garwood converted the data access
mechanism (the "sditerator") to use a MeasurementSet in addition to
the flat table previously used. In addition to spending eight weeks in
National Guard training, Joe McMullin modified the interface of dish
to be fundamentally command line based. A very detailed description of
the use of dish is given in the
Dish User's Manual (AIPS++ Note 236).
We have changed the format of the CDROM for this release. AIPS++ can
no longer be run from the CDROM but instead must be installed to a
disk. This has enabled the two distributions (Linux and Solaris) to
be placed on one CDROM, saving considerable copying and distribution
costs.
Finally, I would like to highlight some of the recent documents in
the AIPS++ Notes series.
The Notes series is used to document
many different things. Designs of major packages are often written
as a Note. The work planned for a development cycle is documented
as a Note. Some recent examples are:
- In the development cycle leading to this third release, we
completed a carefully planned change to a revised version of the
observational data format used in AIPS++: the MeasurementSet. This
second version of the format has been designed to rectify some
shortcomings in the first version, but also to better support a
wider range of observations, including single dish, VLBI, and
optical interferometry. In putting together this definition, we
benefited from extensive discussions with a number of people
throughout the various astronomical communities. The definition
of the MeasurementSet is available at
AIPS++ Note 229, and a
summary of the key changes can be found in the
MeasurementSet Version 2.0 article
in this Newsletter.
- The AIPS++ Measures system is a set of C++ classes and glish
tools that handle measurements with units, coordinates, and
reference frames. The Measures system is documented in the
C++ header files (as is our standard practice) and in the
User Reference Manual. A programmers guide to using the C++
classes is found in
AIPS++ Note 233.
- Throughout its history, AIPS++ has benefited from a number of
software engineering practices. Those interested in the type of
practices that we have found to be useful may find a detailed
description in
AIPS++ Note 237.
- The Display Library is one of the most important packages within
AIPS++. It is designed to provide display capabilities for all
types of data within AIPS++. Originally designed and partially
implemented by Tom Oosterloo and John Pixton, it has been filled
out and extended by David Barnes. An excellent description of the
design, implementation, and use of the Display Library is found in
AIPS++ Note 231.
Tim Cornwell
November 2000
Mark Holdaway
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