Demonstration of Fused RTK (Fixed) + Inertial Positioning Using Android Smartphone Sensors Only

Abstract

This paper describes several experiments related to centimeter accurate positioning using the build-in GNSS receiver and inertial measurement unit (IMU) of a dual-frequency commercial smartphone. Using a choke-ring antenna platform to shield the smartphone from the ground multipath we were able to obtain a GNSS carrier phase (GPS+Galileo L1/L5) solution with good fixed ambiguities and approx. 2 centimeter precision. Furthermore, the GNSS antenna phase center (APC) within the smartphone was determined. An Allan variance analysis of the inertial measurement unit shows an unexpected good gyro bias instability of approx. 15 deg/h. An integrated realtime kinematic (RTK) GNSS+IMU solution was computed and a heuristic sensitivity analysis was performed.