GNSS Odometry: Precise Trajectory Estimation Based on Carrier Phase Cycle Slip Estimation

This letter proposes a highly accurate trajectory estimation method for outdoor mobile robots using global navigation satellite system (GNSS) time differences of carrier phase (TDCP) measurements. By GNSS TDCP, the relative 3D position can be estimated with millimeter precision. However, when phenomenon called cycle slip occurs, wherein measurement jumps and becomes discontinuous, it is impossible to accurately estimate TDCP. Although previous studies have eliminated effect robust optimization technique, was difficult completely eliminate outliers. In this letter, we propose detect slip, amount modify observed TDCP calculate factor graph framework. The acts as loop closure in contributes reduction integration error position. Experiments an unmanned aerial vehicle showed that by modifying proposed method, could accuracy 5-30 cm only single receiver, without any other external data or sensors.