Trajectory Planning for UAV-based Data Collection to Enhance Permittivity Calibration in Ray-tracing.

Location-specific and map-based radio propagation methods are increasingly crucial for wireless systems and applications. These map-based methods such as Ray-tracing (RT) necessitate precise environmental modeling, but acquiring accurate material parameters remains challenging. Emerging practices, by calibrating material parameters through wireless measurements, have been explored. However, considering the cost and limited time of wireless measurements, data collection needs to be optimized for the material calibration in one area. In this paper, a guided data collection approach is proposed for RT model permittivity calibration. Focusing on the flexible scenario of path loss data collection using an unmanned aerial vehicle (UAV), our objective is to present a UAV trajectory planning scheme for path loss data collection within a limited time to enhance permittivity calibration. The numerical results demonstrate that the proposed algorithm is effective in reducing the Cramer- Rao lower bound and detecting all permittivity parameters for permittivity estimation by planning a better estimator.