A Calibration Method for Antenna Delay Estimation and Anchor Self-Localization in UWB Systems

This paper addresses the problem of localization through Ultra Wide-Band (UWB) devices in the case of unavailability of a permanent infrastructure, meaning that an adhoc UWB network has to be installed. Deploying an UWB localization system requires human intervention and calibration phases to measure the positions of the anchor nodes. In this paper, we propose an iterative approach based on the Gauss-Newton algorithm for calibration addressing the compensation of the antenna delay at each UWB node and anchors self-localization by two way ranging. The validation considers real experiments in an outdoor scenario, where we show that the proposed compensation procedure can precisely estimate the antenna delays even when few measurements are available, improving the position estimate of UWB anchors and, accordingly, the tag localization accuracy.