To: Visiting Committee From: Richard Simon Date: 11 March 1996 Subject: Annual Report on Classic AIPS Software Software Overview There are three main elements to NRAO's current software strategy for supporting data processing and analysis. First, AIPS supports the reduction and analysis of (primarily) radio interferometric data. AIPS has extremely broad and flexible capabilities and is certainly used in many other areas of image processing and analysis outside of ordinary interferometric radio astronomy. Second, UniPOPS still supports the reduction and analysis of single dish data, with a strong emphasis on NRAO's two current single dish instruments, the 140 Foot in Green Bank and the 12 Meter on Kitt Peak. These will be phased out as the third element in NRAO software, AIPS++, becomes operational over the next few years. The current distribution of personnel between these three efforts is roughly: AIPS: Four full time positions in Charlottesville, four full time positions in Socorro (including effort dedicated to Orbiting VLBI for JPL) plus two part time people (<~ 25%) (one in Socorro and one in Charlottesville). The goal of this AIPS support is primarily to keep AIPS stable and to provide support as needed for the VLBA and for the VLA survey efforts. UniPOPS: No dedicated personnel; bug fixes and user support are provided as needed. UniPOPS is at a plateau where further development would require significantly greater support for further progress. AIPS++ will replace UniPOPS within the next two years. AIPS++: There are presently eight positions in the AIPS++ project. AIPS++ is discussed in detail in a separate section. AIPS New copyright: The 15JUL95 release is the first release under a new system designed to protect NRAO's intellectual property rights, while making AIPS more readily available to both the astronomy and non-astronomy communities. All files are now copyrighted by Associated Universities, Inc., NRAO's parent corporation, but are made freely available under the GNU General Public License. This means that User Agreements are no longer required, that anyone may obtain a copy of AIPS via anonymous ftp, and that under certain restrictions the software may be redistributed or modified. Supported architectures: We continued our support for the most commonly used architectures in radio astronomical data processing (SunOS 4, Sun Solaris, PC Linux, DEC Alpha, HP-UX, SGI Irix, IBM AIX). The port to Linux has been successful in bringing AIPS to the world of PC users. The use of SunOS 4 is being phased out at the NRAO in favor of the Solaris operating system. We will keep one or more computers on the old system as long as we can and we do not anticipate major problems anytime soon, but it is inevitable that the quality of our support for the old OS will diminish with time. New releases: AIPS had releases in January, 1995; July, 1995; and in January, 1996. The number of shipped releases has increased dramatically from 80 - 100 in previous years to almost 300 for 15JUL95. We assume the adoption of the new copyright has added to the popularity of AIPS. About 80 percent of all shipments take place over the network, the remaining 20 percent is done using various kinds of magnetic tape. Almost 50 percent of all shipments are readily compiled and linked (and therefore operating system dependent) versions of AIPS. We have decided to switch to October and April releases of AIPS; therefore the next release will be 15OCT96. NCSA collaboration: We have tentatively started a collaboration with the National Center For Supercomputing Applications (NCSA). In this collaboration, scientists with extremely large projects can apply for AIPS time on one of NCSA's powerful computers. As of early March 1996, the AIPS installation on one of these computers was nearing completion (see below for more details regarding NCSA). New utilities: One of the benefits of using the GNU General Public License on AIPS is that we are free to include and use other GNU-licensed packages. The first of these is the GNU readline library which provides the user-input interface for AIPS under Unix beginning with the 15JAN96 release. It gives the user the ability to use the cursor-arrow keys, as well as various "control" and "escape" key sequences, to recall previously entered commands, to edit the current command line (without having to back-space and re-type the entire line), to search the command history for previously executed commands, to define customized key bindings for executing commands and macros, and much more. The AIPS Gripe System has fallen into disuse in part because the obsolete mechanism of harvesting the gripes and forwarding them to the programmers collapsed. In an attempt to improve matters and to allow non-NRAO sites to participate in the Gripe System, the GRIPE and GRDROP verbs were changed to e-mail copies of the gripe to a number of system and individual addresses. We hope that this will allow serious problems to be addressed immediately and to restore some responsiveness to the whole system. New software - General: The 15JUL95 version of AIPS saw important improvements in basic capabilities of calibration application, Fourier transforming, and cleaning. These three capabilities are now combined in the task IMAGR, which replaces all previous tasks like UVMAP, HORUS, MX, and WFCLN. Its real appeal is the addition of several new parameters, such as the robustness parameter, developed by Dan Briggs, which allows the user more freedom in choosing the data weighting and shape of the resulting beam. The development of IMAGR was greatly aided by the availability of the Object Oriented Package in AIPS, originally developed by Bill Cotton. A second task is SCMAP, which, like IMAGR, is based on the OOP package. SCMAP is intended to perform imaging, cleaning, and self-calibration iteratively in one task. SCMAP is not new, but has been improved by the addition of all of the new data-weighting and imaging options of IMAGR. SCMAP offers IMAGR's interactive TV options during Clean plus a similar interactive TV display before each self-calibration cycle. New functionalities and improvements were added to other tasks. The various contour plotting tasks were amalgamated into KNTR, which combines all capabilities of the tasks it replaces. The TV handling was improved as well, both in the number of graphics channels and in the way color tables are allocated. The new task CPASS is a version of BPASS that fits polynomials to the bandpass calibration data, and will lead to better spectral signal-to-noise ratios for some applications. The support of handling single-dish data within AIPS was extended and improved. New software - VLBI specific: In the past year, the emphasis of AIPS software development has been in the area of VLBI specific applications. FITLD has been extensively modified to incorporate digital corrections for data processed by the VLBA correlator, and now allows the ability to select data by frequency and bandwidth. PCLOD allows VLBA pulse-cal information to be added to an VLBA dataset. The polarization calibration tasks POLSN and SPCAL were added. Automated data editing was made possible by upgrading the existing task UVFLG, and by adding the new task VPLOT. New software - Space VLBI: The fringe fitting routine BLING, the task BLAPP to apply BLING solutions and a model-fitting task were further enhanced during the past year. This software is expected to be fully functional by the time the VSOP satellite is scheduled to be launched late 1996. Cookbook update: The rapid development in AIPS software over the last couple of years has made it necessary to essentially rewrite the AIPS Cookbook. New chapters were made available on the WWW as soon as they were completed. ADASS: At the ADASS 1995, the yearly conference about data analysis in astronomy, held in Tucson in October 1995, Gustaaf van Moorsel gave a presentation entitled: "AIPS Developments in the Nineties."