Analyzing GPS Accuracy Through the Implementation of Low-cost COTS Real-time Kinematic GPS Receivers in Unmanned Aerial Systems

Blake T. McCollum


The focus of this research is investigating the utility of two small, low-cost, commercial-off-the-shelf (COTS), real time kinematic (RTK) GPS systems. The intent was to comprehend if current low-cost COTS technology performed as well as expensive high-end technology; as well as integrate a RTK system into autonomous flight scenarios. The RTK systems were characterized by test via static and dynamic scenarios, in parallel to a truth source. The results show that overall, in the Ublox NEO-M8P (via C94-M8P) performed better than the Swift Navigation Piksi (original). The Ublox NEO-M8P RTK System obtained a maximum DRMS (Distance Root Mean Square) of 1.6 centimeters, and a MRSE (Mean Radial Spherical Error) of 10.1 centimeters. The Piksi RTK system output an inconsistent data stream, and was therefore disregarded for flight test integration. During the integration of the Ublox NEO-M8P and the 3DR Pixhawk (flight controller), an issue of auto configuration arose between the 3DR and Ublox. A Drotek Tiny RTK was evaluated with the 3DR Pixhawk, with the same configuration issues. System reliability issues were evident throughout this research, including, but not limited to signal blockage and multipath errors. It is recommended that research continue to investigate the use of RTK GPS systems in SUAS applications.