Ge J, Luo W, Dong H, Liu H, Wang H, Wang W, Yuan Z, Zhu J, Zhang H
School of Automation, China University of Geosciences, Lumo Road, Wuhan 430074, China.
Science and Technology on Near-Surface Detection Laboratory, Tonghuixi Road, Wuxi 214035, China.
Rev Sci Instrum. 2020 Mar 1;91(3):035112. doi: 10.1063/1.5134929.
A towed Overhauser marine geomagnetic magnetometer used for weak magnetic anomaly detection in severe ocean conditions is studied to investigate means to reduce the negative effect of dynamic behavior and magnetic noise associated with ocean waves. For the dynamic effect, a continuous polarization workflow is proposed to enhance the free-induction-decay signal, and then, a multi-angle pickup coil and a self-tracking programmable amplifier are used to further reduce the adverse effect caused by uncontrollable changes in the towfish attitude on the signal quality. Furthermore, to achieve adaptive suppression of magnetic noise in different ocean conditions and areas, a modified adaptive Kalman algorithm is assessed. In addition, an optimized Overhauser sensor and a towfish were developed. Overall, the experimental results show that the sensor can effectively suppress the dynamic effect and magnetic noise. Regarding the magnetic sensitivity, uncertainty and range are 12 pT/Hz@1Hz and 0.21 nT and 20 000 nT-100 000 nT, respectively. Moreover, underwater testing was performed to verify the function and the detection of the magnetic anomaly.
研究了一种用于在恶劣海洋条件下进行弱磁异常检测的拖曳式奥弗豪泽海洋地磁磁力仪，以探讨降低与海浪相关的动态行为和磁噪声负面影响的方法。对于动态效应，提出了一种连续极化工作流程来增强自由感应衰减信号，然后，使用多角度拾取线圈和自跟踪可编程放大器进一步降低拖鱼姿态不可控变化对信号质量造成的不利影响。此外，为了在不同海洋条件和区域实现对磁噪声的自适应抑制，评估了一种改进的自适应卡尔曼算法。另外，还开发了一种优化的奥弗豪泽传感器和拖鱼。总体而言，实验结果表明该传感器能够有效抑制动态效应和磁噪声。在磁灵敏度方面，不确定度和量程分别为12 pT/Hz@1Hz、0.21 nT以及20 000 nT - 100 000 nT。此外，还进行了水下测试以验证该仪器的功能和磁异常检测能力。
