Abstract
Geographical Survey Institute and Japan Meteorological Agency have operated a monitoring system for crustal deformations in the Tokai area since 1998, which has performed a baseline analysis using 3-hour GPS data. We investigated precision and characteristics of the coordinate and the baseline length obtained by the analysis. The precision of the baseline length obtained from 3-hour data is a couple of times worse than that obtained from a daily data. Correlation of coordinate variations between every pair of the observation stations was examined, and then the stations were divided into six groups according to the correlation coefficient evaluated. These groups corresponded to both analysis clusters that the station belonged to and classification of the monument/antenna type that was adopted at the station. Alteration to the new analysis strategy has reduced the difference of groups depended on the monument/antenna type.
