Using Clock Frequency Comparison for Deep Space Navigation

As the Deep Space Network (DSN) is becoming overbooked with increasing deep space missions, there is a growing demand for alternative navigation methodologies. According to the theory of relativity, a clock onboard a spacecraft experiences time dilation due to its motion and gravitational effects, causing a frequency shift relative to a reference clock. This study explores the feasibility of clock frequency comparison (CFC) as a complementary method to DSN, using a Mars flyby scenario. From a Monte Carlo analysis, [Formula: see text] position and velocity uncertainties of 200 km and [Formula: see text], respectively, were achieved during the cruise phase. During extended DSN unavailability, incorporating CFC prevents the growth of uncertainty, ensuring a smooth transition upon DSN reacquisition. The convergence rate of a ground filter, initialized with uncertainty propagated during the DSN tracking gap, improved from 91% to 100%. During the flyby phase, [Formula: see text] position and velocity uncertainties of 5 km and [Formula: see text], respectively, were achieved from CFC. Due to differences in the observability and nonlinearity of the trajectory, cruise and flyby phases demonstrate opposite behavior in the position and velocity uncertainties. A B-plane analysis showed that CFC provides information that DSN is less sensitive to, highlighting its complementary role. With further development, CFC could enable more efficient allocation of DSN resources for future missions.