1 Introduction

This document describes the basic reduction of photometric data taken with the Submillimetre Common-User Bolometer Array (SCUBA) at the James Clerk Maxwell Telescope. The adopted method is applicable to the full range of SCUBA’s photometric observing modes: simple ‘stare’ type observations such as those performed with UKT14, small jiggle maps taken with a single pixel or either of the above but chopping between 2 or 3 bolometers on the arrays.

At the time of writing the fully commissioned photometry mode employs a single bolometer to make small 9-point maps centred on the source. This scheme has been shown to give better signal-to-noise under moderate submillimetre ‘seeing’ conditions than the traditional ‘stare’ method. However, the reduction procedure is still valid regardless of the adopted jiggle mode, for example, if a 7-point map or a scheme with no jiggling was used for the observation. Although not yet fully commissioned, it is possible to chop between two or three bolometers on the arrays and the reduction of these data is discussed briefly. In the future more elaborate methods, such as two and three position chopping, will be available and the document will evolve accordingly.

Our basic philosophy was to style the SCUBA photometry reduction graphical interface in a manner similar to that used for UKT14 [2] (i.e. COADD) but the observing modes and hence steps in the reduction process are particular to SCUBA.

This cookbook requires access to the Scuba User Reduction Facility (Surf) software [3] (for processing demodulated SCUBA data), Kappa[4]¹ (for data display and post-processing) and Convert[5] (for exporting data to ASCII or FITS). Surf is available from the Starlinkhomepage.