Millimeter Wave Imaging of Surface Defects and Corrosion under Paint using V-band Reflectometer

Abstract

Periodic inspection of critical metal structures that are used in numerous industries worldwide, is imperative to guarantee structural integrity. These structures are vulnerable to near surface defects and corrosion, which can cause severe repercussions if unattended. An effective, reliable and real time technique for evaluation of anomalies in these metallic structures is the need of the hour. In this paper, millimeter wave imaging of surface defects of practical importance such as holes and notches and corrosion under paint for metallic structures is presented. A reflectometer operating in V-band (50–75 GHz) is employed for imaging and the images produced by the millimeter wave system are benchmarked with the popular Phased Array Ultrasonic Testing (PAUT). It is demonstrated that millimeter wave imaging system is effective in detecting surface defects as well as corrosion under paint and renders high quality images, comparable to PAUT.