ESO Reflex: A Graphical Workflow Engine for Running Recipes

Abstract

Sampo is a 3 year project that began in January 2005. It is led by ESO and conducted by a software development team from Finland as an in-kind contribution to joining ESO. The goal of the project is to assess the needs of the ESO community in the area of data reduction and analysis environments and to create pilot software products that illustrate critical steps along the road to a new system.

The Sampo team has been developing new ways in which instrument pipeline recipes can be executed in a more flexible way. This has led to a prototype application called ESO Reflex that provides a new approach to astronomical data analysis. The integration of a modern graphical user interface and field-proven legacy data reduction algorithms aims to give an astronomer the best of both worlds: ease of use combined with optimal scientific results.

Much of the raw data produced by ESO instruments is reduced using compiled recipes based on the Common Pipeline Library (CPL). Each of these recipes performs a single task in the reduction process and they are combined to form reduction pipelines. Currently such recipes are run one at a time using a command line application EsoRex or the GUI-based application Gasgano. Using ESO Reflex, a sequence of recipes can be run as a workflow and the output of a recipe can be used as an input to another recipe. The workflow can be executed either automatically or in interactive mode, where the user can interrupt processing at intermediate stages to visualize the results and also change the processing parameters if needed. The data classification functionality offered by ESO Reflex (based on Gasgano) helps the user to select the right data for input, which also reduces the likelihood of errors. ESO Reflex also detects errors that occur during the execution of the recipes, and appropriate action can then be taken by the user.

ESO Reflex is based on a graphical workflow engine called Taverna that was originally developed for the molecular biology community in the UK. Workflows have been created so far for several instruments on the ESO VLT and VLTI. The easy-to-use GUI allows the user to make changes to these or create their own workflows.