Propagation over a parabolic valley: Model comparison to data

Performance of long range terrestrial wireless communication is critically affected by terrain variation. Of particular interest is the case of a transmitter (base station) placed above clutter, while the mobile receiver is immersed in clutter. Recently published analytical results provided compact asymptotic expressions for pathloss for clutter-covered parabolic terrain, both for valleys and ridges. In both cases, ray-optical term dominated for short ranges, while a single mode dominated at large ranges. Strong focusing was found to occur in valleys. In this work, analytical predictions are compared to measurements collected across a deep valley formed by the Columbia River in Oregon. In comparison to measured power across a valley, mean errors of less than 1 dB were found, a marked improvement over standard terrain-unaware models that produce a mean error of 30 dB.