Use of PPP Processing for Next-generation Smartphone GNSS Chips: Key Benefits and Challenges

This study evaluates the feasibility of achieving improved positioning accuracy with raw GNSS measurements from recently released smartphones. As a point positioning technique, Precise Point Positioning (PPP) achieves centimetreto millimetre-level accuracy through error mitigation and the use of highly accurate orbit and clock products when applied to geodetic hardware. Using PPP as the processing mode, positioning accuracy and performance of selected newly available devices are analyzed. These devices include the Xiaomi Mi 8, Google Pixel 3, Huawei Mate 20 and Samsung Galaxy S9. All tested devices had the capability of tracking either three or four GNSS constellations, and the first and third track two frequencies. The key research questions to be answered are: (1) What is the typical positioning performance when using the raw measurements from these smartphones in multi-GNSS PPP processing in static scenarios? (2) Given the limitation that the hardware components of the smartphones present, what PPP processing changes can be implemented to enhance the usage of the raw measurements? (3) What is the best performance that can be achieved with multi-GNSS PPP given the usage of the smartphones by the user? In static GNSS PPP processing with a smartphone equipped with a dual-frequency chipset, it was shown that decimetre-level accuracy in approximately half an hour was achievable, comparable to geodetic-grade receiver and antenna. Future work will involve the use of external antennas and the resolution of float ambiguities.