RELATIVISTIC DOPPLER-SHIFT IN SATELLITE TRACKING

The recently launched (June 23, 1977) Navigation Technology Satellite 2 carries aboard it two high‐precision cesium beam atomic standards. The frequencies of these standards were preset to agree with similar ground‐based oscillators to within a few parts in 1012. An analysis of about 4 days of low‐noise Doppler tracking revealed a frequency bias between the orbiting clocks and the ground‐based clocks at the tracking sites. This observed bias was 4.47 parts in 1010, which is consistent with a predicted frequency bias arising from the special relativity time dilation effect coupled with a frequency blue shift predicted by general relativity. This paper is not subject to U.S. copyright. Published in 1979 by the American Geophysical Union.