Enhancing the integrity of integrated GPS/INS systems by cycle slip detection and correction

Satellite navigation systems are widely used for high accuracy applications. Before the carrier phase observable can be utilized as the most accurate ranging information its inherent integer cycle ambiguity must be resolved. The algorithms for ambiguity resolution and carrier phase positioning rely on the ambiguities being constant. However, high dynamics, shadowing or multipath may cause so-called cycle slips which would deteriorate the accuracy if remained undetected. A new method was developed using an integrated system consisting of an inertial measurement unit and a differential GPS (Global Positioning System) sensor. With this method the integrity of cycle slip free carrier phase information is greatly enhanced which was demonstrated in driving tests.