Detection of small GEO debris by use of the stacking method

Abstract

In this paper we propose a new method known as "the stacking method" to detect small pieces of unknown GEO debris, in which several images taken with a CCD camera are used to detect this debris. With this method, the streaks of stars are completely eliminated, and the sky background fluctuation decreases significantly. This allows the detection of very dark debris that is not visible on a single image. We tested this method by using the 45 cm telescope at the Yatsugatake Observatory and a small CCD camera manufactured by Nakanishi Image Laboratory (N.I.L). The globular cluster M13 was observed to evaluate the method and to calculate the limiting magnitude. The three regions of the geostationary orbit were also observed to search for unknown GEO debris. One possible piece of GEO debris about 1 m big was detected as a result of analysis that used the stacking method. The limiting magnitude shows that we can detect GEO debris of about 50 cm in size. With this method, by means of observation using the facilities at the Bisei Spaceguard Center (BSGC), a 1 m telescope, and an SITe CCD camera, we may be expected to detect GEO debris of about 10 cm in size.