This paper presents the results of an experimental program to obtain a better quantitative understanding of low angle microwave propagation phenomena needed to assess the potential for improved elevation tracking performance. It has long been recognized that terrain multipath (e.g., reflections and/or shadowing) are a principal limitation on the achievable accuracy of radar elevation trackers and/or landing navigation aids at low angles; however, there has been a paucity of relevant experimental data over irregular terrain. The experimental data presented were obtained with a 26 lambda L-band array and a 57 lambda C-band array at a variety of sites in eastern Massachusetts with vegetated and/or rolling terrain. It is shown that specular reflections appear to be the predominant multipath source and these are predictable from a model based on scattering from tilted plates.