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.
Chapter Contents
| Introduction | Authors
| References
Table of Contents |
Index | Previous Section
| Next Section