Holographic subsurface imaging radar for applications in civil engineering

Abstract

There is increasing demand in civil engineering to get high resolution images of shallowly buried objects such as steel reinforcements, power and communication lines, pipes, etc. The described in the article radar system employing continuous wave signals was designed to obtain plan view high resolution images at shallow depths. The plan view resolution is achieved by synthetic aperture, which is formed by regular manual scanning. The current design of the system has depth resolution defined by depth of focus rather than by bandwidth. Two narrowband prototypes of the system around 7 and 14 GHz were designed. The estimated resolution of the system in the presented experiments was estimated 2 and 1.5 cm at 7 and 14 GHz respectively. The paper outlines hardware, user and embedded software, hologram reconstruction technique, and selected experimental results.