1.2 The CookBook

This CookBook is intended to help beginning users of the NRAO Astronomical Image Processing System (AIPS) by providing a recipe approach to the most basic AIPS operations. While it illustrates some aspects of AIPS, it does not pretend to be complete. However, it does include detailed instructions for running many important items of AIPS software. With these as a model, the user should be able to run other AIPS software aided by the EXPLAIN, HELP and INPUTS files and the complete index of software given in Chapter 13 of the CookBook. In this edition, some of the chapters have matured into something more like a users’ manual, than a beginners’ cookbook. These sections provide an overview of a few less basic, but nonetheless interesting, programs which often seem to be forgotten even by experienced AIPS users. To assist the beginning and infrequent user, appendices have been added to provide outlines of continuum, spectral-line, and high-frequency calibration procedures, primarily geared to users of the VLA, and a simplified outline of VLBA data reduction. A guide to reduction of data from the historic VLA appears in Appendix O. To assist in finding information in this now large document, an index has been added.

AIPS software is changing and growing continually. This edition of the CookBook describes the 31DEC18 (aka “AIPS for the Ages (Aged), version 19”) release of AIPS. Some chapters have information only from earlier releases. When something only applies to fairly recent versions of AIPS, a comment to that effect is made. Features remain in later releases even if the particular comment does not say as much. There were many changes in AIPS software between the seventh (15JAN94) and the sixth (15JUL90) edition of the CookBook. The chapter on the AIPS calibration package for continuum, spectral-line, solar and VLBI data (Chapter 4) was revised in 2018 to describe calibration and editing of the Expanded VLA. Material applying to the old VLA was moved to Appendix O (old). The list of current AIPS tasks (Chapter 13) has been updated and reflects the extensive improvement and expansion of AIPS software. The chapters on imaging and improving images were merged as were the chapters on interactive and hard-copy displays. These mergers reflect in part the mergers of these operations. The chapter on spectral-line imaging (Chapter 8) has been revised with the assistance of Elias Brinks. Phil Diamond, John Conway, Athol Kemball, and Ketan Desai have rewritten the chapter on VLBI calibration and imaging (Chapter 9). Appendix Z contains instructions and advice peculiar to the individual AIPS sites of the NRAO. This has been revised extensively to reflect the migration of much of the data reduction at NRAO sites away from VAXes and Convex computers to Sun and Linux workstations. The ninth edition has an Index which is current and updates concerning editing, calibration, imaging and single-dish processing in the 15APR98 and later versions of AIPS. This edition still contains, essentially unchanged, the helpful glossary of astronomical and computing terms written by Fred Schwab.

Paper copies of recent editions of the CookBook are no longer available from NRAO. However, much of the AIPS documentation, including the CookBook, is now available on the “World-Wide Web” so that it may be examined and retrieved over the Internet (start with “URL” http://www.aips.nrao.edu). This edition of the CookBook is issued in a ring-binder format with a chapter-based page numbering system. This allows us to update individual chapters without altering the pagination of others and to make each chapter available individually over the Internet. The documentation is also included with every copy of AIPS shipped.

Additional written documentation on AIPS is available in several forms. A programmers’ reference manual called Going AIPS is available in two volumes. This was revised completely for the 15APR90 release due to the upgrading of the AIPS code to FORTRAN-77 and to reflect the extensive additions and improvements to the software. Unfortunately, it has not been revised since but it continues to be quite useful. The first volume is intended for applications programmers, while the second volume is needed by programmers developing AIPS for new peripheral devices or computers. Going AIPS may be obtained from the AIPS web site.

AIPS provides run-time documentation in the form of HELP and EXPLAIN files which may be viewed at the terminal or printed. (See 3.8 for explicit instructions.) Should these not suffice, consult your local AIPS Manager and then, if needed, e-mail the AIPS programmer at daip@nrao.edu. Although individual AIPS programs have often been written, and are best understood, by a single programmer, the AIPS group as a whole assumes responsibility for all released software. Anyone in the group will attempt to help you or, at least, to identify another member of the group better able to help you.

Finally, users are encouraged to recommend new and better analysis and display tools and to help debug the existing software by entering “Gripes” (see 11.1). Please note that examples of bugs that are documented by printouts of inputs, message logs, etc. are most useful to the programmers. Also note that written bug reports are much more effective than verbal reports. E-mail to daip@nrao.edu reaches everyone in the group.