Performance Analysis of Standalone UWB Positioning Inside Forest Canopy

A precise and reliable 2-D/3-D positioning solution is a significant advancement for robotics-assisted surveying in forestry automation. Ultrawideband (UWB) positioning, an outstanding technology for high accuracy and high robustness positioning solutions, has emerged as the most promising candidate to serve this application. It has the potential to reduce the meter-level positioning accuracy of the global navigation satellite system (GNSS) inside forest canopies down to the decimeter level independent of other sensors/measurements. However, to date, little is known about the actual performance of standalone UWB positioning in these environments. In this article, a detailed performance analysis of a standalone UWB positioning system in a GNSS-denied forest environment with slight and serious non-line-of-sight (NLOS) propagations was performed. Positioning accuracy and the effect of the positioning update rate on the accuracy, as well as the time consumption for different positioning methods, were analyzed based on real-world datasets. The results show that the standalone UWB positioning system is able to achieve decimeter-level positioning accuracy that is better than 0.3 m in the OXY plane inside the forest canopy even in the presence of severe NLOS propagations. Therefore, this study provides a valuable reference for positioning solutions in robotics-assisted surveying for forestry automation and also in other location-based applications.