Accurate Ground-based Near-Earth-Asteroid Astrometry Using Synthetic Tracking

作者：Zhai Chengxing^*; Shao Michael; Saini Navtej S; Sandhu Jagmit S; Owen William M; Choi Philip; Werne Thomas A; Ely Todd A; Lazio Joseph; Martin Mur Tomas J; Preston Robert A; Turyshev Slava G; Mitchell Adam W; Nazli Kutay; Cui Isaac; Mochama Rachel M

来源：Astronomical Journal, 2018, 156(2): 65.

DOI：10.3847/1538-3881/aacb28

• astrometry
• atmospheric effects
• methods: observational
• minor planets, asteroids: general
• techniques: image processing

Accurate astrometry is crucial for determining orbits of near-Earth-asteroids (NEAs) and therefore better tracking them. This paper reports on a demonstration of 10 mas level astrometric precision on a dozen NEAs using the Pomona College 40 inch telescope, at the JPL's Table Mountain Facility. We used the technique of synthetic tracking (ST), in which many short-exposure (1 s) images are acquired and then combined in post-processing to track both target asteroid and reference stars across the field of view. This technique avoids the trailing loss and keeps the jitter effects from atmosphere and telescope pointing common between the asteroid and reference stars, resulting in higher astrometric precision than the 100 mas level astrometry from traditional approach of using long exposure images. Treating our ST of near-Earth asteroids as a proxy for observations of future spacecraft while they are downlinking data via their high rate optical communication laser beams, our approach shows precision plane-of-sky measurements can be obtained by the optical ground terminals for navigation. We also discuss how future data releases from the Gaia mission can improve our results.

• 出版日期2018-8