Summit Pipelines

The Data Aquisition System (DAS) will do coadds of multiple reads/consecutive exposures on the same field, apply non-linearity corrections, as necessary, and assemble each multiquadrant read into a coherent whole. For WFCAM this will minimise the DFS requirements to $\approx$100 Gbytes per night. VISTA will generate roughly a factor $\times$4 more data each night.

The main purpose of the summit pipelines is to generate near real-time DQC information by processing data on-the-fly using either library master calibration frames or simple locally derived (from each MSB or OB) calibration data.

For WFCAM the summit pipeline will run under the control of the ORAC data aquisition and processing system and together with the CASU-supplied modules, will produce the required DQC information, the export MEF FITS files and instigate a FITS header and data verification program.

The summit pipelines will have to maintain and update a ``best guess'' series of master calibration frames (dark, flats, skies, hot/bad pixel masks) and to monitor and measure the instrumental non-linearities to provide basic 2D instrumental signature removal. The DQC feedback will probably require some form of catalogue generation software which can be used to produce measures for DQC monitoring, including: astrometric pointing accuracy - requires telescope to point to better than a few arcsec rms; photometric throughput; image shape measures - trailing; sky brightness levels; sky noise levels (details TBD). This latter software should be a subset of the basic pipeline.

As already noted, to minimise data volumes the data aquisition system must carry out basic operations such as reset-correction and stacking multiple sequential exposures (an `integration') in situ before forwarding data to the rest of the system.