GrosbølPreben
Preben Grosbøl, Klaus Banse, Pascal Ballester (ESO)
The vast amount of data expected from the VLT and the multitude of instruments demand that raw data can be reduced highly efficient and with a minimum of manual intervention. The pipeline of the VLT Data Flow System (DFS) has been designed for this purpose and will be used for three main applications: a) near real time reduction of data at the VLT observatory to provide a first assessment of data quality, b) off-line reduction of data at the ESO headquarters to offer users standard reduced data products for service-mode observations, and c) data reduction at the users home institute to make a more customized processing possible.
The DFS pipeline system consists of two main components namely a DataOrganizer (DO) which analyzes incoming data and creates ReductionBlocks (RB) depending on a set of instrument specific rules, and a ReductionBlockScheduler (RBS) which submits the RB's to one or more Data Reduction Systems for execution. The pipeline system can be configured, through a set of ASCII files, to handle several instrument simultaneously. It was designed using the object-oriented methodology and major parts of the baseline version will be written in Java.
The paper presents the basic design of the DFS pipeline and discusses implementation issues of the first Java version.