IRAS Explanatory Supplement
V. Data Reduction
D. Point Source Confirmation
D.2 Overview of Seconds-Confirmation
D.2.a Band Seconds-Confirmation
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In-band seconds-confirmation was done in the position domain rather than the time domain to account for variations in the scan rate. The design of the focal plane permitted legitimate sources to produce pairs or triplets of detections and these modes were handled separately. When neither mode appeared correct, confusion processing was required. Although this salvaged useful detections, it could also let false alarms leak through. The confirmation process, however, may be considered a serial filter arrangement, and so a few false alarms slipping through one stage are very unlikely to penetrate the entire obstacle course.
After accepting a confirmed point source, the flux and position estimates were refined. The multiple observations were used in statistical computations aimed at gathering information about the instrument and the a priori statistics.
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