LAMBDA-Based Ambiguity Resolution for Next-Generation GNSS Wide-Area RTK

In the present contribution we study how the availability of next-generation multi-constellation Global Navigation Satellite Systems (GNSS), such as GPS and Galileo, will improve Wide Area Real-Time Kinematic (WARTK) ambiguity resolution for users receiving corrections as disseminated by the WARTK service provider. For this purpose, multi-frequency GPS and Galileo data of several permanent and rover stations have been simulated using the Spirent Simulator at ESA/ESTEC. These simulated data have been biased by realistic atmospheric and multipath errors. Two (static) user stations have been simulated, at 257 and 413 km from the master reference station. For the ambiguity resolution of these user baselines the LAMBDA method is used in combination with the Fixed-Failure rate Ratio test. For this paper, the LAMBDA method has been applied to resolve the full vector of ambiguities, without a priori forming of linear combinations, such as the wide-lane or narrow-lane. An important conclusion is that the use of integrated GPSGalileo data will dramatically improve the performance of a WARTK user’s ambiguity resolution as compared to GPS only. In this point the usage of a LAMBDA-based approach helps to ensure the carrier phase ambiguity process.