Abstract
As a step to establish the marine geodetic control network around Japan, we performed a simultaneous observation program of Ajisai at Titi-sima and Simosato Hy drographic Observatory (SHO) for January through March, 1988, another at Isigaki-sima and HO for July through September, 1988, and another at Minami-Tori-sima (Marcus Island) and SHO for January through March, 1989. The observation program consists of the satellite laser ranging (SLR) and taking photographic plates of Ajisai at each station. Mainly based on the obtained SLR data, the position of these first order control points, Titi-sima, Isigaki-sima and Minami-Tori-sima, were determined very precisely. For example, the baseline length between Titi-sima and SHO was measured as 937665.041 +/- 0.004m while that between Minami-Tori-sima and SNO was obtained as 2024874.042 +/- 0.007m.
