Research on three-component response of ground-airborne TEM considering emission current waveform

Authors

HOU Yanwei, Xi'an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi'an 710077, China
GUO Jianlei, Xi'an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi'an 710077, China
SI Yinnyu, Xi'an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi'an 710077, China
JIANG Tao, Xi'an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi'an 710077, China

Abstract

The ground-airborne TEM has received more and more attention in coal goaf exploration and other fields. In order to provide a theoretical basis for the processing and interpretation of ground-airborne transient electromagnetic data, it is necessary to study the influence of the transmitted current waveform parameter on the three-component response characteristics of ground-airborne TEM. Taking trapezoidal waves as an example, this article firstly studies the frequency distribution of different emission current waveform, and then investigates the effects of the rising edge time, pulse width and turn-off time of the transmitted waveform on the three-component magnetic field response of ground-air transient electromagnetic based on the three-dimensional finite difference time domain method(3D-FDTD). The results show that the rising edge time basically has no effect on the three-component secondary field response; the turn off time effect on the three-component secondary field response is mainly concentrated before 0.2 ms, and the longer the turn off time, the greater the impact on the pure abnormal response; the pulse width has the main effect on the three-component secondary field response after 0.1 ms, and the shorter the pulse width, the greater the impact on the pure abnormal response. The results of the three-dimensional goaf model show that the characteristics of the off-time and pulse width on the response of the three-component abnormal field and background field are basically the same; the distribution range and depth of anomalous objects can be judged by the three-component pure anomaly field response multi-track map and time track map. The research results will provide some valuable theoretical references for the selection of the parameters of the ground-airborne TEM excitation source waveform.

Keywords

ground-airborne TEM, emission current waveform, 3D-FDTD, three-component

DOI

10.3969/j.issn.1001-1986.2021.05.026

Recommended Citation

HOU Yanwei, GUO Jianlei, SI Yinnyu, et al. (2021) "Research on three-component response of ground-airborne TEM considering emission current waveform," Coal Geology & Exploration: Vol. 49: Iss. 5, Article 27.
DOI: 10.3969/j.issn.1001-1986.2021.05.026
Available at: https://cge.researchcommons.org/journal/vol49/iss5/27

Reference

[1] ZHANG Yingying, LI Xiu. Research progress on ground-airborne transient electromagnetic method[J]. Progress in Geophysics, 2017, 32(4): 1735-1741. 张莹莹, 李貅. 地空瞬变电磁法研究进展[J]. 地球物理学进展, 2017, 32(4): 1735-1741.

[2] XU Yang. Study about 1D forward and inversion of SAEM[D]. Chengdu: Chengdu University of Technology, 2014. 许洋. 半航空电磁一维正反演研究[D]. 成都: 成都理工大学, 2014.

[3] HOU Yanwei. OCCAM inversion for detecting overlying multiple electrical layers above deep coal seams by TEM[J]. Coal Geology & Exploration, 2018, 46(6): 169-173. 侯彦威. TEM探测深部煤层上覆多电性层的OCCAM反演[J]. 煤田地质与勘探, 2018, 46(6): 169-173.

[4] WU Qilong. Semi-airborne transient electromagnetic apparent resistivity imaging and its application in tunnel survey in complex terrain areas[D]. Jinan: Shandong University, 2019. 吴启龙. 半航空瞬变电磁视电阻率成像及在复杂地形区域隧道勘察中的应用[D]. 济南: 山东大学, 2019.

[5] ZHANG Qinghui, TIAN Zhongbin, LIN Jun, et al. Application of time domain electrical source ground airborne electromagnetic system in goaf water exploration[J]. Journal of China Coal Society, 2019, 44(8): 2509-2515. 张庆辉, 田忠斌, 林君, 等. 时域电性源地空电磁系统在煤炭采空积水区勘查中的应用[J]. 煤炭学报, 2019, 44(8): 2509-2515.

[6] NABIGHIAN M N. Electromagnetic methods in applied geophysics: Volume 1, theory[M]. Society of Exploration Geophysicists, 1988.

[7] ELLIOTT P. The principles and practice of FLAIRTEM[J]. Exploration Geophysics, 1998, 29(1/2): 58-59.

[8] SMITH R S, ANNAN P, MC GOWAN P D. A Comparison of data from airborne, semi-airborne, and ground electromagnetic systems[J]. Geophysics, 2001, 66(5): 1379-1385.

[9] MOGI T, TANAKA Y, KUSUNOKI K, et al. Development of grounded electrical source airborne transient EM (GREATEM)[J]. Exploration Geophysics, 1998, 29(1/2): 61-64.

[10] JI Yanju, WANG Yuan, XU Jiang, et al. Development and application of the grounded long wire source airborne electromagnetic exploration system based on an unmanned airship[J]. Chinese Journal of Geophysics, 2013, 56(11): 3640-3650. 嵇艳鞠, 王远, 徐江, 等. 无人飞艇长导线源时域地空电磁勘探系统及其应用[J]. 地球物理学报, 2013, 56(11): 3640-3650.

[11] LI Suyi, LIN Jun, YANG Guihong, et al. Ground-airborne electromagnetic signals de-noising using a combined wavelet transform algorithm[J]. Chinese Journal of Geophysics, 2013, 56(9): 3145-3152. 李肃义, 林君, 阳贵红, 等. 电性源时域地空电磁数据小波去噪方法研究[J]. 地球物理学报, 2013, 56(9): 3145-3152.

[12] ZHANG Yingying, LI Xiu, YAO Weihua, et al. Multi-component full field apparent resistivity definition of multi-source ground-airborne transient electromagnetic method with galvanic sources[J]. Chinese Journal of Geophysics, 2015, 58(8): 2745-2758. 张莹莹, 李貅, 姚伟华, 等. 多辐射场源地空瞬变电磁法多分量全域视电阻率定义[J]. 地球物理学报, 2015, 58(8): 2745-2758.

[13] LI Xiu, ZHANG Yingying, LU Xushan, et al. Inverse synthetic aperture imaging of ground-airborne transient electromagnetic method with a galvanic source[J]. Chinese Journal of Geophysics, 2015, 58(1): 277-288. 李貅, 张莹莹, 卢绪山, 等. 电性源瞬变电磁地空逆合成孔径成像[J]. 地球物理学报, 2015, 58(1): 277-288.

[14] WU Junjie. Study on joint interpretation of borehole and ground-airborne TEM data[D]. Xi'an: Chang'an University, 2018. 武军杰. 地-井与地-空瞬变电磁联合解释方法研究[D]. 西安: 长安大学, 2018.

[15] SUN Huaifeng, LI Xiu, LI Shucai, et al. Three-dimensional FDTD modeling of TEM excited by a loop source considering ramp time[J]. Chinese Journal of Geophysics, 2013, 56(3): 1049-1064. 孙怀凤, 李貅, 李术才, 等. 考虑关断时间的回线源激发TEM三维时域有限差分正演[J]. 地球物理学报, 2013, 56(3): 1049-1064.

[16] LI He. Three-dimensional transient electromagnetic forward modeling in the direct time-domain by vector finite element[D]. Xi'an: Chang'an University, 2016. 李贺. 直接时间域矢量有限元瞬变电磁三维正演模拟[D]. 西安: 长安大学, 2016.

[17] QIN Qingyan. Effect of transmitter current waveform variation on the fixed-wing airborne transient electromagnetic response[J]. Progress in Geophysics, 2013, 28(5): 2673-2679. 覃庆炎. 发射电流波形变化对固定翼航空瞬变电磁响应的影响[J]. 地球物理学进展, 2013, 28(5): 2673-2679.

[18] ZHAO Yue, XU Feng, LI Xiu, et al. Exploration capability of transmitter current waveform on shallow water TEM response[J]. Chinese Journal of Geophysics, 2019, 62(4): 1526-1540. 赵越, 许枫, 李貅, 等. 浅海瞬变电磁全波形响应特征及探测能力分析[J]. 地球物理学报, 2019, 62(4): 1526-1540.

[19] JIANG Sheng. Research on improvement for quality of current waveform of time-domain electromagnetic transmitter[D]. Chongqing: Chongqing University, 2017. 姜升. 瞬变电磁发射机电流波形改善技术研究[D]. 重庆: 重庆大学, 2017.

[20] ZHANG Jun. The high-resolution transient electromagnetic detection technology for ultra-shallow layer in coal mine[J]. Coal Geology & Exploration, 2020, 48(4): 219-225. 张军. 矿井超浅层高分辨率瞬变电磁探测技术[J]. 煤田地质与勘探, 2020, 48(4): 219-225.

[21] GUO Jianlei. Transient electromagnetic method using source array for tunneling ahead geological prospecting of high resolution[D]. Xi'an: Chang'an University, 2017. 郭建磊. 阵列源瞬变电磁法隧道高分辨超前探测研究[D]. 西安: 长安大学, 2017.