Centimeter-Level Positioning for UAVs and Other Mass-Market Applications

To date, high costs and complexity have confined Real Time Kinematic (RTK) technologies to low volume niche markets, such as surveying or construction. However, emerging high volume markets, such as unmanned aerial vehicles (UAV), precision agriculture or robotic guidance systems, require high precision performance that is both energy-efficient and low cost. This paper focuses on the challenges associated with designing and implementing a very precise RTK-based module solution while keeping cost, size, and power consumption as low as possible. In particular, several implementation strategies such as multi-constellation support or single frequency ambiguity resolution are discussed in light of hardware limitations and computational complexity. Following this discussion, the u-blox end-to-end L1 RTK solution, which comprises the NEO-M8P rover and reference modules, is presented. To demonstrate the ability of these modules to achieve cm-level accuracy while meeting the requirements of mass-market applications, several measurement campaigns were conducted. The accuracy of the u-blox NEO-M8P was evaluated under a wide range of signal environments and receiver dynamics. Several walk and UAV data sets were used to benchmark the performance of the NEO-M8P modules against existing L1 RTK products.