GPS連日観測とその大気屈折誤差

Abstract

In order to monitor the crustal movement in Kinki District, southwest Japan, we are continuing daily relative positionings with MINI-MAC2816 GPS receivers. The results show that a relative displacement of 5 cm or smaller will be successfully detected on the Uji-Shionomisaki baseline (162 km), which means that a linear strain of 3×10-7 is detectable. One of main errors in GPS observation is the excess path delay due to water vapor in the troposphere which is hard to be corrected to the level of a few cm by using only meteorological data on the ground surface. We introduced two water vapor radiometers and have started parallel observations with GPS receivers for developing effective correction methods for excess path delay due to water vapor.