2004/03/26 by Steven S. Shapiro, J. L. Davis, D. E. Lebach +1 · 5 citations
Engineering · Earth and Planetary Sciences · Physics and Astronomy · #GNSS positioning and interference #Geophysics and Gravity Measurements #Ionosphere and magnetosphere dynamics
paper · doi:10.1103/physrevlett.92.121101
openalex publication_date 2004/03/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
We used very-long-baseline interferometry (VLBI) to measure the deflection by the Sun of radio waves emanating from distant compact radio sources. This bending is characterized in the parametrized post-Newtonian formalism by gamma, which is unity in general relativity. Using a large geodetic VLBI data set, we obtained gamma=0.9998(3)+/-0.0004(5) (estimated standard error). We found no systematic biases from our analysis of subgroups of data.