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APPENDIX C: BIMA REPORT

In this last cycle, the BIMA AIPS++ group's efforts focused on the four areas:

Enabling calibration of BIMA data,

Support for processing on parallel platforms,

OpenGL-based visualization, and

User outreach.

These efforts included contributions at NCSA from Ray Plante (local manager, 50%), Dave Mehringer (site installation manager, 50%), Harold Ravlin (50%), Anuj Sarma (50%), and Paulo Cortes. In addition, Peter Teuben of the University of Maryland also contributed part time to development and testing.

A special effort was made to build up greater local expertise in the AIPS++ system. Plante, Mehringer, and Teuben traveled to Socorro for ``high-bandwidth'' discussions with experts at NRAO. The establishment of a local users group has also helped build our experience using the AIPS++ package.

BIMA Calibration

Efforts continue to enable end-to-end calibration and imaging of BIMA data. The bulk of the effort this cycle has been in filler development by Plante and Teuben. The previously existing filler, bimafiller, developed and maintained by Teuben, is now designated as the development filler: it is tool to develop and test new capabilities needed in the short term, such as MS-2 compliance and system temperature-based error weighting. It also includes a workaround to the incomplete support for heterogeneous spectral windows in the AIPS++ core library. This filler was used this cycle to support imaging of the BIMA SONG galaxy survey. Plante developed the production filler, mirfiller, based on the experimental development by Teuben. This filler includes full MS-2 compliance and support for heterogeneous spectral windows, multiple sources, and multiple arrays.

Plante and Mehringer outlined the basic calibration strategy for BIMA data, and Mehringer began implementing high-level tools that apply the strategy using the standard calibration infrastructure. Added to the system in this cycle was the bimams tool, which understands the BIMA MS conventions used by the BIMA calibration strategy. This strategy uses wideband averages of data from multiple windows from the same sideband, and bimams supports the recalculation of these averages.

Parallel Platforms

The bulk of the effort this cycle has been spent on porting AIPS++ to experimental 32-bit and 64-bit clusters at NCSA. The 32-bit builds were complete with out change to the basic AIPS++ system or code, and initial timing tests were run using the parallel spectral line imaging and wide-field imaging algorithms. The 64-bit port was incomplete due to the use of immature compilers. Some changes to code were necessary and documented; however the basic 64-bit support infrastructure (see Note 227) appeared to be sufficient to support the new 64-bit clusters at NCSA. Primarily Mehringer and Cortes carried out porting work, with assistance from Plante and Wes Young of NRAO.

Sarma performed general timing tests on the NCSA Origin 2000 and cluster platforms using the wide field imaging algorithm.

OpenGL-based Visualization

Ravlin began his work exploring OpenGL-based visualization with Aipsview. A current motivator for this work is to support large-pixel, multipanel displays at NCSA for displaying large images. Once he gained the basic experience using OpenGL to display astronomical images, he began transferring that expertise to the AIPS++ Display Library with the creation of an OpenGL DisplayCanvas class. This work is on-going.

Outreach

To help prepare BIMA astronomers for processing data with AIPS++, a working group was established at UIUC called the LAI AIPS++ Users Group and Help (LAUGH). It included of AIPS++ developers (Plante, Mehringer, and Sarma) along with two astronomers from the local BIMA group, Lanie Dickel (research associate) and Dave Fong (graduate student). The main activity of this group has been to write the BIMA calibration cookbook for AIPS++ (i.e. a Getting Results chapter). A basic draft is nearly complete.

This committee also sponsored two outreach activities. The first was a series of short tutorials given by Plante at the biweekly UIUC BIMA meetings to introduce users to basic AIPS++ concepts; see
http://monet.astro.uiuc.edu/AIPS++/gentle. The second was a hands-on workshop. The topic of the workshop was multi-scale cleaning; however, this topic was used as a forum for exercising basic skills needed for running AIPS++. This workshop is described in AIPS++ Note 245.