An Experimental Survey of Evaluation Strategies for Constellation Queries

Given a set of query points within an image coordinate system, constellation queries identify the matching points in a database of known points within a standard coordinate system. Constellation queries are an integral part of orientation determination systems used in spacecrafts to orient and navigate themselves. The query points are bright spots in an image captured by a camera on the spacecraft and the database contains known celestial objects in a celestial coordinate system. This paper studies six existing constellation query processing strategies (Angle, Interior Angle, Spherical Triangle, Planar Triangle, Pyramid, Composite Pyramid) using a unified algorithmic framework and presents experimental evaluation of the six strategies. We find that the Pyramid strategy in its simplified form has the best accuracy to runtime ratio given simulated images with false positives, false negatives, and Gaussian noise.