The Calibration Data Archive and Analysis system for PDS, the high energy instrument on board the SAX satellite.
The PDS (Phoswich Detection System) is an array of four phoswich scintillation detectors (800 cm geometric area) to be flown on board the Italian astronomical satellite SAX (Frontera et al., Advances in Space Research , 11 , 281 ). On ground tests and calibrations on the assembled instrument are scheduled to start by the end of this year and to continue, with various steps, up to the pre--launch phase. Tests on electronics were already performed (Frontera et al., IEEE Trans. Nucl. Sci. , in press). During the operational phase the PDS group at TeSRE will continue to monitor the in flight performance of the instrument, and will mantain an archive containing in flight data and calibrations to be used for this monitoring. In this paper we report the architectural design of the data analysis and archival system for PDS calibration data. The data will be obtained both from ground calibrations, and during the operative phase of SAX. The system is based on a network of workstations, with one of them (a HP9000/735 workstation) acting as a database server, and the others as clients. The system includes ~ 3 GB of magnetic disc space (current figure; to be upgraded in the next phases), magnetooptical rewritable disks, CD-ROMs. The data archival is based on a commercial relational database. Data hierarchy will be described and data retrieval will be outlined. Data analysis will be based on both home--made tools and on IDL. Even if PDS is a non--imaging instrument, moderate capability to manipulate pseudo--images (matrices of counts versus Pulse Height Amplitude versus Pulse Shape) is required. Some of the required functionalities are non--standard image manipulations. A scheme of data reduction and of data manipulation will be presented. Current status of the realization will be discussed.
Astronomical Data Analysis Software and Systems III
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