AIPS: 3rd Quarter 2002

Distribution and Versions

              The 31DEC02 version of AIPS now has been in routine operation for nine months, under the new CVS configuration for the midnight jobs. Counts of midnight-job fetches were resurrected in the 3rd quarter, and show approximately 50 sites running the new midnight job. This is considerably more sites than were active under the old “secure-shell” midnight job, indicating that the CVS configuration has made life easier for the remote users. Monitoring of remote downloads of the frozen 31DEC01 version, by ftp, is expected to be completed in the 4th quarter of 2002.

Key Developments


1.           A new task, WIPER, was added to provide interactive editing of data using a plot of the (u,v) data on a TV screen. Various options, for flagging data or for removing flags for data previously flagged with WIPER, are available.

2.           The VLA data-filling task, FILLM, has been changed to allow the reading of disk files. This will be important for use with the upcoming on-line VLA data archive. Minor bugs in file counts and the handling of channel 0 data also were fixed in FILLM.

3.           The UVCON task that is used to simulate (u,v) data, particularly for configuration studies for ALMA, SKA, and EVLA, has been modified to improve its mosaicing capabilities. The various mosaicing imaging tasks (e.g., VTESS) and AIPS “include” files have been changed to permit up to 4096 fields (pointings) to be imaged.

4.           QUACK was given an option (“TAIL”) to flag all sources for a user-specified time after the end of a scan. This deals with a minor VLBA feature in which a few antennas are not recorded as being off source until a second or two after a scan actually ends.

5.           The task FRPLT, which plots fringe-rate spectra, has been rewritten completely to expand the plot options.

6.           The multi-source fitting task, SAD, was fixed to correct mistakes in the reports of errors of source sizes in major and minor axes.

7.           FITLD had an error in computing the apparent positions of sources, because general relativistic corrections had not been included. This has been fixed.

8.           IMAGR has been modified so that it will avoid remaking all images in the middle of cleaning the images, if at all possible.

9.           More friendly/flexible naming of output text files has been made available within AIPS.

10.         The AIPS Cookbook was modified to include all the above changes, and more.

11.         The guide to low-frequency imaging is dependent on observers who are postdoctoral fellows, and has been delayed by their other activities.

Goals for Fourth Quarter 2002


1.           Continue user support and bug fixes, as the major portion of AIPS effort.

2.           Freeze 31DEC02 version of AIPS, and begin new daily-updated 31DEC03 version.

3.           Add monitoring of ftp downloads of frozen AIPS version..

4.           Add new task for fitting antenna positions, needed by the data analysts after VLA reconfigurations..

5.           Add low-frequency/wide-field imaging appendix to AIPS Cookbook.

6.           Incorporate VLBA calibration pipeline into AIPS midnight job release.

Central Development Laboratory