Figure 5: Measurements of the coefficient from light deflection and time delay
measurements. Its GR value is unity. The arrows at the top denote anomalously large values from
early eclipse expeditions. The Shapiro time-delay measurements using the Cassini spacecraft yielded
an agreement with GR to percent, and VLBI light deflection measurements have reached
0.01 percent. Hipparcos denotes the optical astrometry satellite, which reached 0.1 percent.