Tree attenuation at 869 MHz derived from remotely piloted aircraft measurements

Tree attenuation results are described based on data acquired from an experiment employing UHF transmissions at 869 MHz between a remotely piloted aircraft and a stationary vehicle. The objective of the experiment was directed toward providing input to the land mobile satellite community where the extent of shadowing from roadside trees represents important information to be used for system design. Single trees were found to attenuate between 10 to 20 dB with an average median attenuation of 12 dB.