Land Mine Detection by Polarimetric and Interferometric Radar

(1)地表和不均匀土壤造成的杂波一直是探地雷达面临的严重问题。为了减少杂波，提出了采用阵列天线进行偏移信号处理和数据采集的方法。(2)在人道主义排雷中，地表扫描有时比较困难，讨论了使用单迹线识别埋藏目标的计量方法。在这项研究中，我们证明了可以从单个轨迹的时频表示中提取目标特征，并显示了实验室测试结果。(3)双基地雷达的发射机和接收机位于分开的位置。如果我们在固定位置使用发射器，并且只扫描小型接收器，则探地雷达的操作会更容易。我们建议在本研究项目中为双基地探地雷达系统使用光电场传感器。光电场传感器是一种无源小型传感器，适合用于人道主义排雷的探地雷达系统。我们开发了该系统，并证明该系统可以对干沙中的埋地雷模型进行成像。(4)先进雷达系统应采用雷达偏振测量和干涉测量等新雷达概念。用于识别的雷达极化测量将很有用，我们为此测试了天线阵列的布置。通过控制发射器和接收器的偏振状态可以减少地表的反射。我们建议在生物静态探地雷达系统中使用该技术。除了用于人道主义排雷的探地雷达外，我们还在各种雷达平台上测试了雷达偏振技术，包括钻孔雷达和地基合成孔径雷达（GB-SAR）。（5）我们在阿富汗、埃及、克罗地亚和柬埔寨等受地雷影响的国家对所开发的传感器进行了评估测试。现场经验对于传感器的进一步开发是非常有用的反馈。同时，我们也能清楚地了解人道主义排雷的情况和技术需求。

(1)Clutter due to ground surface and inhomogeneous soil always is always serious problem for GPR. In order to reduce the clutter, we proposed migration signal processing and data acquisition by an array antenna.(2)In humanitarian demining, scanning on the ground surface is sometimes difficult and metrologies to use a single trace for identification of buried targets were discussed. In this study we demonstrated extracting target features from Time-frequency representation of a single trace can be sued, and laboratory test results were shown.(3)A bistatic radars have the transmitter and the receiver at separated positions. If we use a transmitter at fixed position, and only a small receiver is scanned, the operation of GPR can be easier. We propose in this research project to use an optical electric field sensor for the bistatic GPR system. an optical electric field sensor is a passive, small sensor and it fits to GPR systems for humanitarian demining. WE developed the systems, and demonstrated the system can image buried landmine models in dry sand.(4)New radar concept such as radar polarimetry and interferometry should be adopted for advanced radar systems. Radar polarimetry for identification will be useful, and we tested arrangements of antenna arrays for this purpose. The reflection from the ground surface can be reduced by controlling the polarization status of the transmitter and receiver. We propose to use this technique in the biostatic GPR system.In addition to the GPR for humanitarian demining, we tested radar polarimetry technique to various radar platforms including borehole radar and Ground-Based SAR (GB-SAR).(5)We conducted evaluation tests of the developed sensor in mine affected courtiers including Afghanistan, Egypt, Croatia and Cambodia. The experience in the field is quite useful feedback for further development of the sensor. Also, we could understand the situation of the humanitarian demining and needs for technologies quite clearly.