### 1 Introduction

The Orac-dr pipeline (SUN/230) is a suite of recipes and primitives for the automated processing of raw instrument data into scientifically-useable products. However, this is only the start point for the analysis and further operations on these data is inevitable. The PIpeline for Combining and Analyzing Reduced Data (Picard) is a modification to Orac-dr which allows pipeline-processed data to be manipulated using generic, instrument-independent methods. Furthermore, it is inefficient to begin at the computationally-expensive raw data stage again for every minor adjustment to the analysis. Thus Orac-dr and Picard together represent two halves of the data reduction and analysis workflow.

This document will describe the basics of using Picard and contains a summary of available processing recipes.

#### 1.1 Document conventions

In an attempt to make this document clearer to read, different fonts are used for specific structures.

Starlink package names are shown in small caps (e.g. Smurf); individual task names are shown in sans-serif (e.g. makemap). Picard recipe and primitive names are also shown in sans-serif and are always upper case (e.g. REMOVE_BACKGROUND).

Text relating to filenames (including suffices for data products), key presses or entries typed at the command line are also denoted by fixed-width type (e.g. % smurf), as are parameters for tasks which are displayed in upper case (e.g. METHOD).

References to Starlink documents, i.e., Starlink User Notes (SUN), Starlink General documents (SG) and Starlink Cookbooks (SC), are given in the text using the document type and the corresponding number (e.g. SUN/95). Non-Starlink documents are cited in the text and listed in the bibliography.

File name suffices represent the text between the final underscore character and the three-letter .sdf extension. For example, a file named s4a20101020_00002_0001_cal.sdf has the suffix _cal.