基于Overhauser传感器的近地表UXO磁梯度法探测技术  

The detection technology of near-surface UXO based on magnetic gradient method and Overhauser sensor

作　　者：葛健[1] 陆承达 董浩斌[1] 刘欢[3] 袁志文 赵志卓 刘咏华 朱俊 张海洋 

机构地区：[1]中国地质大学自动化学院,武汉430074 [2]中国地质大学机械与电子信息学院,武汉430074 [3]中国地质大学地球物理与空间信息学院,武汉430074 [4]近地面探测技术重点实验室,无锡214035

出　　处：《仪器仪表学报》2015年第5期961-974,共14页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(41474158);国防预研项目(404070201);国家重大科学仪器设备专项(2014YQ100817);中央高校基本科研业务费专项资金(CUG110822);近地面探测技术重点实验室开放课题(TCGZ2015A008)项目资助

摘　　要：实现对UXO的有效探测对保障战时己方人员安全与装备机动,以及战后人民生命财产安全和地区经济发展都具有重要的意义。目前,我国在UXO探测领域,方法理论研究方面,存在基础相对较薄弱、相关文献很少的问题;探测仪器方面,存在传感器灵敏度低(不能分辨小型航弹产生的微弱异常场)、信号提取手段落后的问题。针对这些问题,通过采用磁梯度探测方法、高精度Overhauser传感器来提高UXO探测灵敏度。首先,建立了适合航弹磁法探测的三度体的圆柱体模型,并对航弹的ΔT磁异常和垂直磁梯度异常进行了数值模拟和比较;然后,进行了背景磁场干扰和物理模型实验,验证了磁梯度法的可行性和优势;在此基础上,研究了动态核极化效应、自由基物质、Larmor信号的处理和抗干扰设计,并最终研制了基于动态核极化效应的Overhauser传感器及样机,在人工磁场发生空间中的测试结果表明其不确定度和国外主流传感器一致,均为0.3 nT。最后,在野外进行了对25 kg航弹的探测实验,测试结果表明其极限探测距离可以达到2.5 m,优于国产现役的探测器。Realizing effective detection for UXO plays a significant role in people＇s life,property security and regional economic development. At present,in our country in the UXO exploration field there exist the problems,such as unsubstantial fundamental study,lack of relevant literature; the problems about the detection instruments are low sensor detection sensitivity,unable to detect the weak magnetic field generated by small aerial bomb,poor signal extraction means,low automation level and etc. Aiming at these problems,this paper adopts magnetic gradient detection method and high precision Overhauser sensor to improve the detection sensitivity for UXO. Firstly,a three-dimensional cylinder model suitable for the electromagnetic method of aerial bomb detection was established; and the numerical simulation and comparison of ΔT magnetic anomaly and vertical magnetic gradient anomaly of the aerial bomb were conducted. Then,the experiments on background magnetic field interference and physical model were conducted,the feasibility and advantage of the magneticgradient method were verified. On this basis,the dynamic nuclear polarization effect,free radical material,Larmor signal processing and anti-interference design were studied; and the Overhauser sensor and prototype based on the dynamic nuclear polarization effect were finally developed. The test results in the artificial magnetic field show that the measurement uncertainty of the geomagnetic field reaches 0. 3 nT,which is consistent with that of foreign mainstream sensors. Finally,the field experiments for detecting aerial bomb were carried out,the test results show that the limit detecting depth of the sensor for aerial bomb with weight of 25 kg reaches 2. 5 m,which is superior to that for the domestic commissioned detector.

关 键 词：Overhauser传感器 近地表UXO 磁梯度法 三度体 自由基 

分 类 号：TH762[机械工程—仪器科学与技术]