Diffraction by rocket exhausts

Abstract

Abstract : Review of Titan IIIC flight data shows that VHF and C-band signals received in the shadows of the rocket exhaust propagate by diffraction around the plume. Scale-model experiments show that the intensity of such signals depends primarily on the diameter of the plume and the position of the antenna and only slightly on either the plume shape or surface. It is shown that lower bounds for signal strength can be calculated with a straightedge diffraction model. It is concluded that the simple mathematical model constitutes a useful tool for the planning of communications and tracking systems for launch vehicles. (Author)