Accurate Near-Earth-Object Astrometry using Synthetic Tracking and Applications

Synthetic tracking technique uses multiple short exposure images to observe moving objects to prevent the objects from streaking in an individual frame. It integrates frames in post-processing, where the tracking of telescope at any desired rate can be simulated by shifting frames accordingly. Such an approach avoids trailing loss, thus improves detection sensitivity, especially for fast moving objects. It also yields accurate astrometry for moving objects independent of rate of motion with precision comparable to stellar astrometry. Using the Gaia DR2 catalog, we are able to demonstrate 10 mas level near-Earth-object (NEO) astrometry with the synthetic tracking technique. Accurate NEO astrometry allows us to determine NEO orbit more precisely. We discuss applications such as cataloging newly discovered NEOs with less measurements and/or from observation time windows covering shorter orbit arcs, better predicting the chance for a potentially hazardous asteroid to impact the Earth, measuring non-gravitational acceleration to infer physical properties of minor planets, and optical navigation for future spacecraft carrying optical communication lasers.