Doppler-aided EWL Cycle Slip Detection and Repair Method

Global Satellite Navigation System (GNSS) has become one of the most important infrastructural facilities for major countries in the world. GPS carrier phase observations are often used for high precision positioning, but are susceptible to the influence of cycle slips. The EWL (extra-wide-lane) combination, for longer combination wavelengths, is frequently used for detecting and repairing cycle slips. The EWL combination adopts carrier phase and pseudorange observations; but in some cases, pseudorange observations have proven to be imprecise or inapplicable. Based on the traditional EWL model, a Doppler-aided EWL cycle slip detection and repair model is proposed herein. The model is applicable to situations where the ionosphere is stable and the sampling rate is high. Analyzing the static experimental data with 1s sampling interval, it could be observed that combining the proposed new method with traditional EWL method before adding any cycle slip will lower the first-order difference of integer ambiguity down to less than 0.5 cycles. This implies that the new method is also applicable to cycle slips detectable and reparable by traditional EWL methods. However, the ionospheric delay term reintroduced by the new method still requires further research.