Let us begin with a rough outline of the steps that you might take in analysing your data in AIPS.
The succeeding sections describe these steps in detail. In addition, a flow chart showing a suggested path through the analysis maze is provided at teh end of this section. The steps shown can sometimes be moved about in order.
You may want to make as good a calibration as possible with MIRIAD (see § 3.3 for a discussion on this). Although you could work entirely within MIRIAD, it may be preferable to combine the best features of AIPS with those of MIRIAD. This generally means loading your data into AIPS, editing it to remove bad data, and then shipping the data to MIRIAD for calibration and imaging. Generally, the TV display and image analysis software is better in AIPS than MIRIAD, so you may then return to AIPS (although MIRIAD does offer reasonable software in all these areas). See the MIRIAD manual for more information.
Before actually loading your data into AIPS, it is useful to discuss some of the general methods employed by the AIPS calibration package. I will assume some working knowledge of AIPS. If you are inexperienced with AIPS, then read the AIPS Cookbook, or ask for help from an unfortunate colleague or from your ATNF support scientist (if you are at Epping). There are also fairly extensive HELP files in AIPS, and even more extensive EXPLAIN files. Appendix A presents a list of some tasks that are relevant to the calibration and imaging procedures. Longer lists can be found in the AIPS Cookbook.
In general, I will not explain all AIPS adverbs that you must fill in for each task. If they are self-evident or well documented, then I leave it up to you. If I think they need specific discussion then I will do so; in particular, a group of adverbs used for most of the calibration tasks is discussed in Appendix B.
Your initial aim in AIPS will be to build what is called a multi-source visibility file. This file contains visibility data for many sources (possibly with different frequencies and bandwidths). The concept of the calibration package is that you never touch the actual data in the multi-source file, you just derive tables that are applied to the data in order to correct them. These tables are attached to the multi-source file and are specific types of what are called extension files. The number and type of extension files present can be ascertained with the general header viewing task, IMHEAD. Multiple versions of extension files can be kept, and there is a suite of tasks to delete, copy, and generally manipulate them (see Appendix A).
Examples of extension files that are not tables are the history (HI) and plot (PL) files. The tables applications tasks will not function on non-tables extension files. A correct use of the myriad of tables that the calibration package produces is essential. Appendix C explains what the most common tables you will encounter in AIPS are for and what some of their contents mean. Please take the time to read this.
As well as multi-source visibility files, AIPS also supports single-source files. As indicated by the name, these contain data for one source only. After you have finished calibrating with multi-source files, it is often convenient to apply the calibration directly to the data and split sources off into single-source files. The calibration tables are eliminated, as the actual visibilities will have been corrected. This saves you the book-keeping that goes along with keeping track of the calibration tables. Extension files such as the AN, HI, and PL files can still be attached to single-source files. The only calibration table that will generally become associated with single-source files is the solution (SN) table, because this is used in the self-calibration procedure.
It is also possible, depending on exactly what sort of imaging you wish to do, to work entirely with the multi-source files and not bother with splitting off sources into single-sources files. This may be advantageous if you have a large number of sources in your observation.