Abstract :
Earth-Mars radar ranging data such as produced in the ‘Viking’ mission can be used to measure two effects from relativistic gravity, both comparably sensitive to alternative theory parameters — the radar propagation delay signal proportional to Eddington parameter 1 + γ, and a polarization of the Earth and Mars orbits toward Jupiter proportional to 4β − 3 − γ and indicating anomalous gravitational to inertial mass ratio of the sun. When the two are considered together, inspection of the ranging experimentʹs covariance matrix finds that well mixed combinations of the two theory parameters γ, β, not the two separate effects, are independent observables. Measurement precision of these parameters are independent observables. Measurement precision of these parameters are tabulated for some past and future cases. A ‘correlated data filter’ is described which can reduce systemic errors in Earth-Mars range produced by unmodeled asteroid perturbations.