A reduction method for magnetic disturbance caused by DC railway system

Earth, Planets and Space

Zhuoxuan Li¹  Yunju Wu¹  Shuangmin Duan¹  Lindong Pan¹  Xuezhen Ding¹  Yanxin Yin¹  Yuguo Li² 

[1] College of Marine Geoscience, Ocean University of China, 266100, Qingdao, China;College of Marine Geoscience, Ocean University of China, 266100, Qingdao, China;Laboratory for Marine Mineral Resources, Pilot National Laboratory for Marine Science and Technology (Qingdao), 266237, Qingdao, China;

关键词: Direct current (DC) railway system;    Magnetic disturbance;    Adaptive Kalman filter;   

DOI  :  10.1186/s40623-021-01428-x

来源: Springer

【 摘 要 】

The stray current of direct current (DC) railway systems causes magnetic disturbance in geomagnetic measurements, which may complicate the identification of useful information. The magnetic disturbance exhibits broadband characteristics in the frequency domain. In this paper, we propose a noise reduction method based on the adaptive Kalman filter to extract useful signals from the geomagnetic data with a high level of noise. The covariance matrixes of both the process noise (Q) and measurement noise (R) can be adaptively estimated to improve the performance of the adaptive Kalman filter. The proposed method is adopted to process the geomagnetic data collected at the Beijing Geomagnetic Observatory (BJI), which is affected by the DC railway system. The magnetic disturbance is largely reduced, and the signal-to-noise ratios of the horizontal and vertical components of the geomagnetic field are improved by more than 14 dB and 27 dB, respectively. The K-indices are calculated to evaluate the performance of the adaptive Kalman filter method. To assess the influence of the adaptive Kalman filter on natural signals, the geomagnetic data that contain rapid variations are processed. The denoising results show that the adaptive Kalman filter can effectively reduce the magnetic disturbance caused by DC railway system without large impact on the natural geomagnetic rapid variations.

【 授权许可】

CC BY