Abstract
The range precision of Satellite Laser Ranging (SLR) techniques reaches one centimeter level today. However, even the accuracy of ordinary orbital determination of semi-long arc as five-days-arc remains at ten centimeters level and this high precision of ranging has not been effectively, used. Moreover, if we use longer arc technique to estimate precise baselines, worldwide SLR data should be used. It takes time to prepare worldwide SLR data and to complete the computation. If we estimate precise baseline lengths in a region of a diameter of a few thousands kilometers it is shown that we can use a specific short arc technique named SPORT which uses SLR data obtained simultaneously at two or more nearby SLR stations for successive passes instead of ordinary long arc technique. As an example of application of the SPORT, it is shown that baseline change for Quincy-Monument Peak line of about 884 km in California estimated to be -31 mm/year by using LAGEOS SLR data from August, 1984 to July, 1987. This result coincides with values given by other techniques. The baseline length between Simosato and Titi sima which was measured by using a fixed SLR system at Simosato and a newly developed transportable station by the Hydrographic Department of Japan was also determined as 937, 665.041±0.004 m using the same techni que. We also propose to use this technique for quick detection of symptoms of crustal deformation before a big earthquake.
