Earth Rotation Measured by Lunar Laser Ranging

Abstract

The estimated median accuracy of 194 single-day determinations of the earth's angular position in space is 0.7 millisecond (0.01 arc second). Comparison with classical astronomical results gives agreement to about the expected 2-millisecond uncertainty of the 5-day averages obtained by the Bureau International de l'Heure. Little evidence for very rapid variations in the earth's rotation is present in the data.

Universal time: Results from lunar laser ranging

“…The more accurate the measurements of UT, and the higher their temporal resolution, the better the opportunity to study these phenomena and to disentangle one from another. Laser ranging to the retroreflectors on the moon [Stolz et al, 1976] and very long base line interferometry [Shapiro et al, 1974] are the two modern techniques that appear to hold the greatest potential for improving the determination of UT. Here we present estimates of UT determined from analysis of 5 years of lunar laser ranging observations by the McDonald Observatory, and we compare these estimates with those obtained by the Bureau International de l'Heure (BIH) and also with those obtained by Stolz et al, who analyzed most of the same laser ranging data but with a different method.…”

Geodetic monitoring of tectonic deformation in the Australian region

“…The former is required for investigating aspects of the theories of relativity and the latter provides information on the physics of the lunar interior (Mulholland, 1980). The laser range observations also provide information on the Earth's rotation, in both polar motion and changes in the speed of rotation (e.g., Stolz et al, 1976). The latter quantities not only have their own intrinsic interest (Lambeck, 1980) but also enter into the equations of motion of the artificial Earth satellites.…”

Earth Rotation Variations – Long Period

“…The EOPs are typically determined from LLR data by analyzing the residuals at each station after the lunar orbit and other parameters such as station and reflector locations have been fit to the range measurements Langley et al, 1981a;Stolz et al, 1976). From this single-station technique, two linear combinations of UT1 and the polar motion parameters p x (t) and p y (t) can be determined, namely, UT0 and the variation of latitude Df i (t), at that station:…”