High accuracy real-time precise point positioning using the Japanese quasi-zenith satellite system LEX signal

The Quasi-Zenith Satellite System (QZSS) is a regional navigation satellite system transmitting navigation signals that are compatible and interoperable with GPS, as well as transmitting augmentation signals that carry bias correction messages. The L-band Experimental (LEX) signal on the E6b frequency delivers correction messages - such as orbits and clock information, which enable Precise Point Positioning (PPP). Since March 2013, Australian and Japanese researchers have conducted collaborative investigations in order to evaluate the QZSS LEX signal and the quality of the broadcast correction messages for real-time PPP. The QZSS LEX has been tested in both static and kinematic positioning modes in Australia. The results have been compared to positioning solutions derived from conventional positioning techniques such as Real-Time Kinematic (RTK), as well as those derived from the International GNSS Service's (IGS) real-time service. Decimetre level positioning accuracies in real-time have been obtained in both static and kinematic tests. Furthermore, a prototype system of an 'Australian-generated LEX corrections' has been developed. This paper presents the results of investigations into the feasibility of using the QZSS LEX signal to deliver a high accuracy real-time positioning service to Australian GNSS users. This is a collaborative research project between the Australian Cooperative Research Centre for Spatial Information and Japan Aerospace Exploration Agency (JAXA).