title: An Improved High-Sensitivity Airborne Transient Electromagnetic Sensor for Deep Penetration.
abstract: The investigation depth of transient electromagnetic sensors can be effectively increased by reducing the system noise, which is mainly composed of sensor internal noise, electromagnetic interference (EMI), and environmental noise, etc. A high-sensitivity airborne transient electromagnetic (AEM) sensor with low sensor internal noise and good shielding effectiveness is of great importance for deep penetration. In this article, the design and optimization of such an AEM sensor is described in detail. To reduce sensor internal noise, a noise model with both a damping resistor and a preamplifier is established and analyzed. The results indicate that a sensor with a large diameter, low resonant frequency, and low sampling rate will have lower sensor internal noise. To improve the electromagnetic compatibility of the sensor, an electromagnetic shielding model for a central-tapped coil is established and discussed in detail. Previous studies have shown that unclosed shields with multiple layers and center grounding can effectively suppress EMI and eddy currents. According to these studies, an improved differential AEM sensor is constructed with a diameter, resultant effective area, resonant frequency, and normalized equivalent input noise of 1.1 m, 114 m², 35.6 kHz, and 13.3 nV/m², respectively. The accuracy of the noise model and the shielding effectiveness of the sensor have been verified experimentally. The results show a good agreement between calculated and measured results for the sensor internal noise. Additionally, over 20 dB shielding effectiveness is achieved in a complex electromagnetic environment. All of these results show a great improvement in sensor internal noise and shielding effectiveness.
authors.affiliation: College of Electronic Science and Engineering, Jilin University, Changchun 130012, China. chenshudong@jlu.edu.cn.
authors.forename: Shudong
authors.initials: S
authors.lastname: Chen
authors.affiliation: College of Electronic Science and Engineering, Jilin University, Changchun 130012, China. guosx@jlu.edu.cn.
authors.forename: Shuxu
authors.initials: S
authors.lastname: Guo
authors.affiliation: College of Electronic Science and Engineering, Jilin University, Changchun 130012, China. whf@jlu.edu.cn.
authors.forename: Haofeng
authors.initials: H
authors.lastname: Wang
authors.affiliation: College of Electronic Science and Engineering, Jilin University, Changchun 130012, China. evergreen92@163.com.
authors.forename: Miao
authors.initials: M
authors.lastname: He
authors.affiliation: College of Electronic Science and Engineering, Jilin University, Changchun 130012, China. 18204319478@163.com.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Liu
authors.affiliation: College of Electronic Science and Engineering, Jilin University, Changchun 130012, China. 18443143119@163.com.
authors.forename: Yu
authors.initials: Y
authors.lastname: Qiu
authors.affiliation: College of Electronic Science and Engineering, Jilin University, Changchun 130012, China. zhangshuang@jlu.edu.cn.
authors.forename: Shuang
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Science and Technology on Near-Surface Detection Laboratory, Wuxi 214035, China. yuanzw2008@126.com.
authors.forename: Zhiwen
authors.initials: Z
authors.lastname: Yuan
authors.affiliation: Science and Technology on Near-Surface Detection Laboratory, Wuxi 214035, China. zhyzhyzhy001@126.com.
authors.forename: Haiyang
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Science and Technology on Near-Surface Detection Laboratory, Wuxi 214035, China. csdfangdong@163.com.
authors.forename: Dong
authors.initials: D
authors.lastname: Fang
authors.affiliation: Science and Technology on Near-Surface Detection Laboratory, Wuxi 214035, China. harry_zhu@163.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
keywords: EMC design; deep penetration; sensor internal noise; transient electromagnetic sensor