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Given the absolute
accuracy and uniform global scale provided by the global SLR network
which routinely tracks high altitude satellites like Lageos, the product
of Newton's gravitational constant and the mass of the Earth, GM, has
been determined to unprecedented accuracy and is among the best
determined of the geophysical constants. Ries et al., [1992] report
on a recent SLR solution which utilized data acquired on Lageos, Starlette
and Ajisai, and included background modeling of General
Relativistic effects, yielding a value of 398600.4415
.0008
(1
) km
/sec
. The primary limitations in the accuracy of
this estimate are potential biases in the range calibrations or
refraction model. The two color lasers under development have the
potential to improve this estimate even further.
U.S. National Report to IUGG, 1991-1994
Rev. Geophys. Vol. 33
Suppl., © 1995 American Geophysical Union