Analysis of GPS Dual-frequency Single Differenced Receiver Hardware Delay

The hardware delays of several dual-frequency GPS receivers are investigated based on single differenced model in the ultra-short baselines,and regressed by a linear regression model.Additionally,the single clock-error parameter model for dual-frequency observations is proposed.Experimental result shows that the hardware delays for all receivers are rather stable in time domains,and some of which are even free of time correlation,and the others with significant time correlation can be regressed with a linear model very well.It is also shown that the position solutions of two models are exactly equivalent with the assumption of tracking the same satellites and the equal accuracies for all observation at two frequencies.The accuracy of estimator can be significantly improved by using the single clock-error parameter model.