Wide band propagation measurements and modelling for low altitude UAVs

Unmanned aerial vehicles (UAV) are expected to be used extensively in the near future in commercial applications such as aerial surveillance, transportation and disaster assistance, among other applications. In order to succeed, a development of new air-ground propagation channel models are necessary for UAVs to improve communications links for control and high capacity for the transmission of payload information. In this paper, measurements are carried out in wideband with a channel sounder developed which uses narrow pulse technique. Power delay profile measurements and parameters such as RMS-Delay Spread or average delay profile are analyzed for vertical and horizontal flights in sub-urban environments at L-band. The results show that multipath propagation decreases at higher altitudes.