Introduction

Mapping is the last stage in processing data from the IRAM Plateau de Bure Interferometer (PdBI). Since this is the last stage, we assume you are familiar with interferometry concepts, and you have good knowledge of the CLIC program. Here we introduce parts of the GILDAS (Grenoble Image and Line Data Analysis Software) software that have not been used in previous stages of data analysis.

Data calibration consisted of using a single (big) program from the GILDAS package, CLIC, and a single type of data, the .IPB files. In the mapping stage, the astronomer will use all the tools of GILDAS: a big program for data display, and many image processing programs called Tasks. He (or she) will also manipulate two or three kinds of data: Images, Tables, and UV Tables. An introduction to GILDAS is available in the GILDAS manual. One of the essential feature of GILDAS is its orientation towards spectral line mapping: most tasks handle 3-dimensional data cubes, processing all frequency planes in the same way. cm

The astronomer has three basic ways to proceed:

• the naked GRAPHIC and Tasks
  The GRAPHIC program is used to activate tasks (via command RUN) and to display the task results. All tasks are available in such a way.

• the tailored GRAPHIC and Tasks
  For the most frequently used tasks, procedures have been prepared to ease parameter specifications. Interaction with the task is performed from GRAPHIC via the procedure INPUT and GO. The normal RUN command is still available for those tasks wich cannot be controlled by INPUT and GO.

• MAPPING
  MAPPING is a superset of GRAPHIC with additional commands to make maps and deconvolve them. Because of its full interactivity, MAPPING offers more flexibility than the basic tasks. However, new developments are often available as tasks before being incorporated in MAPPING . Since MAPPING is a superset of GRAPHIC, the two other possibilities can be used directly from MAPPING .