The NOAO Mosaic Data Handling System

The NOAO Mosaic CCD Camera consists of 8 CCDs producing an 8K x 8K format. The Mosaic Data Handling System (MDHS) receives the data in real time as it is read out of the detector. A data feed client (DFC) receives data packets from the detector system and broadcasts them on a message bus. A data capture agent (DCA) receives the data and writes it to a distributed shared image (DSIM). The images are displayed as they are read out by a real-time display (RTD) and are recorded to disk as multi-extension format (MEF) FITS les by the DCA. The DCA triggers a data reduction agent (DRA) to do standard pipeline processing and archiving with a graphical user interface (GUI) for user interaction. The MDHS provides a suite of IRAF data reduction tools for the user and the DRA which are tailored for the MEF mosaic data. The tools provide capabilities for quick-look analysis of the data, basic CCD calibration, mosaic reconstruction, and combining of dithered observations into a fully populated (gaps removed) image.