Autonomous Information Gathering Guidance for Distributed Space Systems with Optical Sensors

Spacecraft to spacecraft tracking using optical sensors is a promising approach to autonomous navigation of distributed space systems. Previous works have shown that optical spacecraft to spacecraft tracking can provide an absolute navigation estimate for all vehicles in the distributed system, but the relative range between the spacecraft is often weakly observable. The observability issues motivate the development of guidance capabilities to gather information on a desired subspace of the state, such as relative range, to ensure accurate state estimation. This paper starts by developing a simplified model and heuristic policy for information gathering with optical measurements. Then a general analytic guidance policy for information gathering is derived. The guidance methods are tested via a covariance analysis with cislunar dynamics and an optical sensor. In all test scenarios the analytic method is fast to calculate and nearly optimal, making it suitable as an autonomous guidance algorithm for information gathering.