IRAS Explanatory Supplement
V. Data Reduction
F. Asteroids and Comets
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To achieve the objective of high reliability in the measurement of inertially fixed sources, the survey required that a source be repeatedly detected on several time scales (see discussion in Section V.D.1). This multiple confirmation process provided the means of detecting and rejecting objects moving at a variety of angular rates with respect to the inertial sky and the orbiting satellite. Detections which failed seconds-confirmation were due to radiation hits and infrared sources near the spacecraft, such as material emitted by IRAS itself space debris, and Earth orbiting satellites. Failures at hours- and weeks- confirmation were used to detect comets and asteroids, effectively rejecting them from the catalog.
Solar system objects moving across the sky more rapidly than about 1' per hour failed the hours- confirmation test. This test was used during the mission to search for fast-moving objects and resulted in the discovery of six comets, an extensive cometary debris trail, and two Apollo asteroids, one of which may be an extinct cometary nucleus. The details of the search for fast moving objects are given in Section III.D.1.
Asteroids and comets moving more slowly than 1' per hour would hours-confirm, and thus reside in the WSDB. To assess the efficiency of the weeks-confirmation filter, the coordinates of ail hours-confirmed sources were positionally associated with the coordinates predicted from the orbital elements of asteroid numbered 1 through 2736, 12 periodic comets, and the 6 outer planets. The tagged sources enabled one to trace known solar system objects through the confirmation process. An analysis of these sources is given in Section VII.F.
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