코드 바이어스를 고려한 GPS Common-View Time Transfer 기술

Abstract

The common-view technique is a simple but elegant way to compare two clocks or oscillators to each other. In this paper, we analyze the performances and limitations of the common-view time transfer according to the measurement errors such as the ionospheric error, the ephemeris error and the code bias error. The code bias is the common-oscillator hardware or local environment delays for each observation. Generally, the code bias is identified initially but it is then neglected or assumed to be negligible. However the code bias has a time-varying property so that a proper removal method is necessary to improve the performance of the time transfer. This paper presents the effect of the code bias and shows the improved performance of the time transfer using a time-difference technique to reduce the effect of the code bias.