Obstacle gain at microwave frequencies

Calculations of expected transmission loss over a single obstacle path show that if conditions are right the loss will be less than if the obstacle were not there. Compared to diffraction loss over a smooth earth, this so-called "obstacle gain" can be appreciable. During 1957, a study and experimental investigation of the obstacle gain effect in the microwave region was completecd. This paper discusses experimental methods and results, describes siting and prediction techniques, and outlines the instrumentation employed in the program. Theoretical and measured losses were in good agreement.