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3 May 1979 Focas-Faint Object Classification And Analysis System
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A system for detecting and classifying images on astronomical plates is described. In particular, the very faint and barely resolved images of 24th magnitude galaxies are shown to be detectable and distinguishable from stellar images of similar brightness. The algorithms and other implementation con-siderations used in the construction of FOCAS are given. Detection and classification at 24th magnitude is achieved with N2 presensitized IIIaJ plates exposed for one hour in the KPNO 4-m telescope prime focus camera. For a digital 6000x6000 pixel image made from the central square area 37' on a side approximately 16000 objects are found to 24.7 mag on such plates. Since the resulting catalog of objects is 3 or 4 magnitudes deeper than existing surveys a variety of internal tests must be used to assess the accuracy and completeness of the list of objects. The tests and simulations made to support these claims are also discussed.
© (1979) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
J. F. Jarvis and J. A. Tyson "Focas-Faint Object Classification And Analysis System", Proc. SPIE 0172, Instrumentation in Astronomy III, (3 May 1979);

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