AIPS quarterly report (Q2), July 08 1999 ---------------------------------------- Versions -------- The current TST version of AIPS (15OCT99) is distributed nightly to all NRAO sites and to 7 non-NRAO sites in the US, Europe and Japan. Full support for SVLBI processing has been available since 15APR98. The 15OCT98 version of AIPS has been distributed to over 302 sites, running Solaris, Linux, DEC Alpha, HP and SGI versions. The overall number of AIPS installations has continued to grow over the last two years. The majority (75%) of AIPS distributions are now received by ftp, although the CD-ROM distribution is still in stong demand. General Issues -------------- - Raised the number of sub fields available in IMAGR to 512. This change has been made to support low-frequency observing on the VLA. Also changed coordinate handling to allow very large offset angles and the special coordinates used by East-West interferometers. - Changed all tasks which use Clean components as the data model to support the large number of fields, to handle the new coordinates, and to offer a user-set flux limit for the components used in the model. - Added option to do Steer-Dewdney-Ito Clean as well as Clark Clean in IMAGR. Also added option to remove weak, isolated Clean components from the Clean model. - LWPLA has been changed to produce multi-page plot files. - The ability to specify which antennas to use for gain normalization when running amplitude self-cal in CALIB has been added. - FITLD now writes data weights that reflect the integration time of the sample. - The VLBA phase-cal task PCCOR now allows IF selection for the case when two bands are observed simultaneously, for example S/X observations typically used in astrometry/geodesy. - CL2HF - Dave Gordon at GSFC has supplied a new version of CL2HF that is reported by R. Gaume at USNO to produce acceptable results on one of the RDV experiments. - Added support for Solaris on PCs; this allows large (>2GB) files on PCs. Full support for large files in Linux is epxected late 1999. Bugs ---- - The 15APR99 release corrected a wide variety of bugs in the calibration application and imaging software. Bugs in bandpass calibration, 3D gridding of data during imaging, handling of source-table frequency offsets, and SPLIT were corrected in the last few weeks preceding the release. - Patches have been issued for problems affecting little-endian computers' handling of the TV image catalog, dispersive delays in TECOR and APGPS, buffer handling in RESEQ, and compressed data in CLIP, DTCHK, and RESEQ.