Novel Approach to Autonomous Lunar Localization and Timing

Abstract

The ability of a deep space spacecraft to estimate its position, velocity, and clock errors without external clock error estimation is investigated. A novel approach to onboard estimation of clock errors is proposed. The effects of clock bias and drift on spacecraft position and velocity errors are derived. These derived equations are leveraged to design a Kalman filter that processes optical measurements along with one-way ranging or two-way position updates from the ground. Simulations are performed to numerically validate the proposed approach and show good localization and timing estimation performance even with lengthy tracking data gaps.