Ultra-low Altitude Channel Measurement in Riverside Environments at 1.4 GHz

To facilitate UAV-based wireless communications, a comprehensive understanding of the wireless channel characteristics is critical. However, most existing studies focuse on the high-altitude channel, while limited attention is paied to the ultra-low altitude channels given the evident difficulties in the measurement of the latter scenario. In this paper, we have tackled the challenges of lightweight channel sounder system design enabling aerial mounting and flying to facilitate the ultra-low altitude UAV channel measurement. We specially focus on the ultra-low altitude channel at 1.4 GHz, which is recently authoried in China to particularly facilitate UAVs applications. With extensive measurements in a riverside area, we analyze the propagation properties and enlighten the large-scale fading and small-scale fading characteristics, where the large-scale parameters are revealed and the Log-logistic distribution is evaluated as the best fit to characterize the small-scale fading. These findings provide important guidance for the ultra-low altitude UAV communication particularly in the riverside scenarios.