AIPS

AIPS is a set of programs for the analysis of continuum and line VLBI observations involving one or more BB channel. These programs are available for a wide range of computer operating systems, including various flavors of Linux and the Mac-OS/X operating system. Sections 28.1 and 28.3 give contact information. Extensive on-line internal documentation can be accessed within AIPS. An entire chapter in the AIPS Cookbook (NRAO staff, 2007) provides useful ``how-to'' guidance for those reducing VLBI data, including discussion of VLBA calibration transfer, space VLBI, polarimetry, and phase referencing. Appendix C of the AIPS Cookbook provides a step-by-step guide to calibrating many types of VLBA data sets in AIPS, employing simple VLBA utilites, including calibration modifications for VLBA+VLA data sets. A new ``frozen'' version of AIPS (currently 31DEC06) is produced each year, and a newer version (currently 31DEC07) is updated and made available throughout the calendar year. Observers are encouraged to use a very recent version of AIPS, since new capabilities such as improved astrometric calibration and simpler data-reduction procedures are implemented frequently.