2020 年 56 巻 8 号 p. 403-411
RC radar is often used as a preliminary survey in renewal works for reinforced concrete (RC) structures. Because the RC radar linearly scans linear polarization antennas, the linear targets such as reinforcing bars and thin power lines perpendicular to the polarization is sometimes missed and is damaged in works of concrete coring. Therefore, a freehand RC radar is required which can flexibly scan to the arbitrary direction with arbitrary rotation angle. In this paper, we propose a calibration method of alignment and sensitivity errors of sensors for 2D positioning system of antennas using two optical mouse sensors. In addition, we integrate RC radar and positioning system, and show that freehand scan of circularly polarized antenna is effective for visualization of buried thin electric wire with 3D imaging results.