Remote Sensing Laboratory, Bauman Moscow State Technical University, Moscow 105005, Russia.
Russian University of Transport, Moscow 127994, Russia.
Sensors (Basel). 2019 Mar 19;19(6):1376. doi: 10.3390/s19061376.
The use of microwave holography for detecting rail surface defects is considered in this paper. A brief review of available sources on radar methods for detecting defects on metal surfaces and rails is given. An experimental setup consisting of a two-coordinate electromechanical scanner and a radar with stepped frequency signal in the range from 22.2 to 26.2 GHz is described, with the help of which experimental data were obtained. Fragments of R24 rails with surface defects in their heads were used as the object of study. The radar images of rail defects were obtained by the described method based on back propagation of a wavefront. It is shown that polarization properties of electromagnetic waves can be used to increase the contrast of small-scale surface defects. A method of estimating rail surface profile by radar measurements is given and applied to the experimental data. Comparison of the longitudinal rail head profiles obtained by radar and by direct contact measurements showed that the radar method gives comparable accuracy.
本文研究了微波全息术在检测铁轨表面缺陷中的应用。简要回顾了现有的金属表面和铁轨缺陷雷达检测方法的相关资源。描述了一种由两坐标机电扫描器和雷达组成的实验装置，雷达的阶跃频率信号范围为 22.2 至 26.2GHz，借助该装置获得了实验数据。研究对象是头部带有表面缺陷的 R24 铁轨片段。通过基于波前反向传播的描述方法获得了铁轨缺陷的雷达图像。结果表明，电磁波的偏振特性可用于提高小尺度表面缺陷的对比度。给出了一种通过雷达测量估计铁轨表面轮廓的方法，并将其应用于实验数据。通过雷达和直接接触测量得到的纵向轨头轮廓的比较表明，雷达方法具有相当的准确性。
