Centralized Processing of Multiple Smartphone Raw Measurements with Fixed and Known Position Onboard a Vehicle

Arnau Ochoa Banuelos (1) , Jan Bolting (2) , Xiao Hu (2) , Paul Thevenon (2) , Bryan Cazabonne (1) , Matthieu Pascaud (1) , Arnaud Ginestet (1)

1 C-S Group - CS Group - SI Toulouse [France]
2 ENAC - Ecole Nationale de l'Aviation Civile

The capacity to obtain precise positioning using smartphones has become conceivable in recent years thanks to the release of multi-constellation, multi-frequency smartphones. Furthermore, from 2016 GNSS raw measurements are made available to developers on Android smartphones. For these reasons, and considering that smartphones have access to the Internet, it is plausible to aim at implement decimeter-level positioning techniques on these devices. Nonetheless, smartphones also have some flaws when using them as GNSS receivers. Firstly, the GNSS antenna and the rest of the electronics are embedded inside the body of the smartphone. This causes the signals to be received at a low signal-to-noise ratio and can cause small interference that further degrade the received signal. Secondly, smartphone manufacturers usually put low-cost GNSS chips in their smartphones since the manufacturing cost of the device comprises many more components. Therefore, the quality of the hardware cannot be compared to that of the high-end GNSS receivers that are commonly used for high-accuracy positioning applications. The objective of this project is to obtain the best accuracy from a set of GNSS measurements that are obtained with smartphones. This project is comprised within the Google Smartphone Decimeter Challenge. For this competition, the Android GNSS team released a pool of datasets containing GNSS and inertial measurements obtained with smartphones on different locations around the San Francisco Bay Area. This article presents the solution that has been implemented for this competition. One interesting characteristic of the data published by Google is that many trajectories contain measurements from more than one phone. For this reason, we decided to combine the measurements from multiple receivers in an RTK implementation. This method allows estimating the position, velocity, and attitude of the vehicle while at the same time improving the accuracy of the positioning.

Domaines: Sciences de l'ingénieur [physics]

Arnau Ochoa Banuelos, Jan Bolting, Xiao Hu, Paul Thevenon, Bryan Cazabonne, et al.. Centralized Processing of Multiple Smartphone Raw Measurements with Fixed and Known Position Onboard a Vehicle. 34th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2021), Sep 2021, St. Louis, United States. pp.3004-3020, ⟨10.33012/2021.18043⟩. ⟨hal-03450489⟩