Accurate boundary extraction and dielectric constant estimation method for UWB internal imaging radar

Microwave ultra-wideband (UWB) radar systems have numerous advantages for high range resolution and an ability to penetrate dielectric objects. Internal imaging of dielectric objects by UWB radar is a promising nondestructive method of testing aging roads and bridges and a noninvasive technique for medical diagnoses or human vital sign detection. We have already developed an original method called as range points migration (RPM), which achieves accurate and high-resolution imaging for target with continuous boundary shape. In this paper, we introduce the novel method for extracting double-layered dielectric object by using RPM or Envelope based approaches, where a dielectric constant of surrounding medium is simultaneously determined. The results obtained from the numerical simulation and experiment assuming concrete objects, demonstrate the effectiveness of our proposed method.