1 July 1990 CCD guidance system for the William Herschel Telescope
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The CCD autoguider detector system for the William Herschel Telescope (WHT) comprises a Peltier cooled, slow-scan CCD camera supported by an MC68020-based VME computer for image processing. The detector is a fluorescent dye coated EEV P8603 CCD chip operated in frame transfer mode. The CCD controller enables a full image to be read out during acquisition, but with windowed readout during guiding so as to permit an increased frame rate. The windowing is controlled by the VME computer, which is also used to calculate the centroid of the guide star and provides a local user interface, displaying images and guider status information. Special attention has been paid to the CCD drive clocks and bias voltages, enabling a very low dark current to be achieved (2 electrons per pixel per second at -35 C) without the need for extreme cooling. Guiding to magnitude 19 on the WHT has been demonstrated during dark time, with an integration time of one second.
© (1990) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
David J. Thorne, Nicholas R. Waltham, Graham M. Newton, Ian G. van Breda, Martin Fisher, and P. J. Rudd "CCD guidance system for the William Herschel Telescope", Proc. SPIE 1235, Instrumentation in Astronomy VII, (1 July 1990); doi: 10.1117/12.19106; https://doi.org/10.1117/12.19106

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