3D image reconstruction of reinforcing bar and pipe using handy microwave radar scanning system

In this report, an advanced signal processing method for microwave radar is considered to reconstruct a precise 3D image for inner construction in concrete structuresC which consists of reinforcing bars and pipes. An antenna positioning error and an inappropriate signal processing method have caused a degradation of reconstructed images. First, a handy antenna scanning system has been modified, which enables real-time self-position measurement. Concretely, a wheel uplift phenomenon is restrained by stabilizing a compress force to a target surface, and positioning accuracy can be improved. On the image reconstruction result, a superposition of observed data cannot operate well in a region sandwiched by two scanned trajectories. Then, a pipe-shape model is newly introduced, and the 3D object´s images have been reconstructed assuming that a continuity of buried object based on it. As a result, buried object´s properties can be evaluated more precisely. An effectiveness of a proposed method has been confirmed experimentally, by applying it to a concrete test specimen and an actual wall.