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 postprocessing 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.

Its advice touches most aspects of law, but it is especially influential for its interpretation of constitutional provisions that rarely, if ever, are subject to judicial scrutiny. While its importance is acknowledged by journalists, law professors, and legal practitioners, political science has yet to incorporate OLC systematically into studies of the presidency outside the ambit of war and emergency powers-areas where OLC achieved notoriety during the George W. Bush administration. We argue that there are unique and important reasons for political scientists to study OLC beyond its War on Terror legacy. In this essay, we construct a theory-driven research agenda for incorporating OLC into studies of the rhetorical and administrative presidencies, Neustadtian bargaining and the unilateral presidency, and transformative bureaucracy.

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