AIPS++ Newsletter
November 2000
AIPS++ News


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