Drone-Based Forest Propagation Measurements for Ground-to-Air EMI Applications

This letter describes measurements of path loss caused by a leafless, mid-Atlantic deciduous forest on ground-to-air (G-A) paths using a drone-based measurement system. The focus of these measurements is on slant paths with low elevation angles (<; 10°) and large foliage depths (up to 500 m) for G-A electromagnetic interference environments involving interference from large numbers of cell phone uplink emissions at military aircraft sharing the same band. Measurements of excess foliage attenuation versus foliage depth are compared to various models, some of which have not appeared in the literature previously. A particularly simple model for predicting forest attenuation on slant paths at low elevation angles is presented that compares favorably with the measurements.