On-board clock correction by drift prediction

This paper presents a new correction procedure for an on-board crystal clock in SS-TDMA and baseband processing satellites in which the drift is almost linear with time. The clock drift is approximated by a polynomial function on the basis of cumulative phase error measurements. The approximating function is then used to predict the drift in the next correction interval. This general correction procedure considers the effects of clock drift, quantization error, Doppler shift, prediction error, and other secondary error terms.