Pole Position for 1971 Based on Doppler Satellite Observation.
NAVAL WEAPONS LAB DAHLGREN VA
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The instantaneous position of the earths spin axis with respect to the crust has been computed daily since 1969 on the basis of Doppler satellite observations. Improved sets of observing station coordinates and gravity field coefficients obtained in 1970 were used through 1971 yielding pole positions with a standard error of about 0.5 meters for the mean of five days of data. However, for some time periods, a bias of about 0.5 meters also exists between the Doppler pole positions and positions reported by the Bureau International de LHeure BIH based on astronomical data. Spot checks of latitude residuals and pole positions based on recomputed satellite orbits for 1968 and 1969 yielded results consistent with recent data, indicating significant compensation of station coordinate errors by changes in orbit constants. Author
- Spacecraft Trajectories and Reentry