A building curtain wall security inspection system based on terahertz wave imaging

Abstract

A non-destructive security inspection system for building curtain walls based on millimeter wave imaging was designed to address the difficulty in detecting internal components of building curtain walls. This system is based on the principle of active millimeter wave imaging, which can scan the components inside the curtain wall and image them in the upper computer. It mainly includes a terahertz wave irradiation source and receiver, as well as a point-to-point imaging system consisting of a pair of 90 ° off axis parabolic mirrors and a semi-transparent and semi-reflective mirror. In order to simplify the system structure, a scheme of transmitting echoes along the same path is proposed. This scheme has a simple structure and can effectively solve the problem of the echo signal being affected by the reflected waves generated by the upper and lower surfaces of the curtain wall and the oscillating reflected waves generated between the lower surface of the curtain wall and the metal components during the process of millimeter wave penetration through the curtain wall. It can also achieve point-to-point clear imaging with an imaging accuracy of approximately 3 mm.