Satellite measurement group composed of members in frequency and time measurements section, CRL, have been developing satellite laser ranging (SLR), GPS time receiver and two-way INTELSAT time transfer techniques. With regard to the development of VLBI, we would offer evaluation measures of accuracy in geodetic and time comparison results. We would also contribute the construction of IERS reference frame by their collocation with VLBI.
In January 1990, CRL's new satellite laser ranging (SLR) facility with a l.5m diameter telescope at Tokyo has started the observations to the major laser satellites. It participated in intensive tracking campaign for Russian satellite, ETALONs, during a period from September to November in 1990. From this campaign, global position of Tokyo SLR station is determined with the precision of several centimeters. The difference of coordinates between SLR and VLBI at Tokyo SLR station are less than 10 cm. Fig.1 shows positions of Tokyo SLR station (CRLLAS) and Kashima VLBI station. Fig.2 presents the estimated precision for each stations during ETALON campaign.