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Fig. 3.20 Distribution of SLR stations around the world. Source: ILRS
25-30 cm. The electro-optic receiver utilizes a microchannel plate photomultiplier
tube (MCP-PMT), receiving by multiphoton. The single-shot ranging precision
with the LAGEOS satellites is 1-1.5 cm, of which MOBLAS has a high precision
of 7-8 mm because of its strong echo, ranking top in the world. TLRS-2, with its
small energy of 10 mJ and poor signal-to-noise ratio, has a less accurate single-shot
ranging precision of 2 cm. Since the 1990s, small mobile stations have almost come
to stagnation due to lack of funds. To make full use of the existing equipment,
NASA redistributed five of the MOBLAS stations. In 1998, one was moved to
Tahiti, an island in the South Pacific. Then in 2000, another one was moved to
Hartebeesthoeck in South Africa.
The NASA network has retained its leading position in SLR throughout the
world and has advanced technologies and high accurate ranging. Its number of
observations represents about half of those of over 50 global stations that run
normally.
EUROLAS
European Laser Consortium (EUROLAS), set up in 1989, now consists of 18 sta-
tions, of which the most important are Herstmonceux in Britain, Graz in Austria,
Grasse in France, Wettzell and Potsdam in Germany, Zimmerwald in Switzerland,
and Matera in Italy. Because the weather conditions in Europe are not as favorable
as in America and Australia, the number of observations in European stations is
comparatively smaller. However, the Herstmonceux station has a larger number of
observations due to its better system stability. Equipment in the Graz station in
Austria is very advanced, so the single-shot ranging accuracy of LAGEOS is 8 mm,
ranking first in Europe. The weather conditions in the Grasse station are favorable,
so the number of observations is accordingly greater. With a longer history and
more advanced equipment, Wettzell station now possesses a set of large-scale
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