Finding Very Small Near-Earth Asteroids using Synthetic Tracking
We present a new technique that is designed to significantly increase the sensitivity for finding and tracking small and fast moving near Earth asteroids (NEAs). The technique relies on a combined use of a novel data processing approach and a new generation of high-speed cameras which allow taking short exposures of moving objects at high frame rates, effectively “freezing” their motion. Although the signal to noise ratio (SNR) of a single short exposure is insufficient to detect the dim object in one frame, by shifting successive frames relative to each other and then co-adding the shifted frames in post-processing, we synthetically create a long-exposure image as if the telescope were tracking the object with a significantly higher SNR. We call this approach “synthetic tracking.” In addition to the enhancement of the SNR for asteroid detection, synthetic tracking also improves the astrometric accuracy of the detected objects relative to background stars. We apply this technique to observations of two known asteroids conducted on the Palomar 200-inch telescope and demonstrate the improved SNR and the 10-fold improvement of astrometric precision over the traditional long exposure approach. In the past 6 years, about 150 of NEAs with absolute magnitudes H=28 mag (~10 m in size) or fainter have been discovered. With an upgraded version of our camera and a field of view of (28 arcmin)^2 on the Palomar 200-inch telescope, synthetic tracking could allow detecting of up to 80 such objects per night including very small NEAs, with sizes down to 7 m.
Michael Shao, Bijan Nemati, Chengxing Zhai, Slava G.Turyshev, Jagmit Sandhu, Gregg W. Hallinan, Leon K. Harding (Submitted on 12 Sep 2013)
Comments: 11 pages, 9 figures, revtex4
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:1309.3248 [astro-ph.IM]
(or arXiv:1309.3248v1 [astro-ph.IM] for this version) Submission history From: Slava G. Turyshev [v1] Thu, 12 Sep 2013 19:22:22 GMT (220kb)
