The effect of GNSS receiver clock biase on double differenced carrier phase measurement

Carrier phase measurement is one of the most important measurements of GNSS receiver, which can be used for precise positioning. In order to achieve a reliable and high precise position, a high quality carrier-phase measurement is needed. Although carrier phase is very precise, there are also many factors in the receiver that will influence the carrier phase measurement performance. The relationship between the manufacturing costs and the high performance is a significant challenge. In order to make low costs, crystal oscillator is used in most GNSS receivers, which can introduce clock biases. This paper discusses GNSS carrier phase measurement model and how it is generated firstly. After that, the influence of clock bias on the double difference carrier-phase measurement is analyzed particularly. A new method is also proposed to remove the influence of the clock biases using instantaneous Doppler frequency and clock biases. Experimental results of zero-baseline test show that the influence of clock biases can be reduced by correcting the error term using the proposed method.