MicrOBEM: a micro-ocean-bottom electromagnetic receiver
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摘要: 海底电磁接收机主要用于海底大地电磁与可控源电磁信号高精度观测。针对现有海底电磁接收机(OBEM-Ⅲ型)体积大、功耗大、成本高等不足,开展了小型化、低功耗、低成本方面的技术研究。MicrOBEM小型海底电磁接收机开发了新的低功耗控制单元、低功耗前置放大器,配置了低功耗磁通门传感器,采取先进的电源管理技术,使得整机功耗由现有海底电磁接收机(OBEM-Ⅲ型)的1 600 mW下降至500 mW(搭载感应式磁传感器配置)以内。针对传统的声学释放器昂贵、笨重(需要匹配更多的浮力材料)等问题,通过集成水声通讯模块,并增加外置的电腐蚀释放装置方式实现释放回收,MicrOBEM仅需一个直径为17 in(1 in=2.54 cm)的玻璃浮球作为浮体,大幅降低仪器的体积和硬件成本,提升了设备的集成度和作业效率。MicrOBEM的体积(不含测量臂等)相比OBEM-Ⅲ减少3/4,功耗减少2/3,成本降低1/2,并于2021年3月在南海南部开展了深水大地电磁试验,其大地电磁测量功能得到初步验证,具有小体积、低功耗、低成本的优势。Abstract: Ocean bottom electromagnetic receivers (OBEMs) are mainly used for high-precision observation and measurement of magnetotelluric signals and controlled-source electromagnetic signals at the sea bottom. To overcome the shortcomings of large volume, high power consumption, and high cost of the existing OBEMs (OBEM-Ⅲ type), this study conducted technical research regarding miniaturization, low power consumption, and low cost. As a result, the overall power consumption of the existing OBEMs (OBEM-Ⅲ type) has been reduced from 1 600 mW to 500 mW or less (by equipment of inductive magnetic sensors) due to the development of a low-power control unit and preamplifier, the installation of low-power fluxgate sensors, and adoption of advanced power management technology. Traditional acoustic releasers are expensive and bulky and require more suitable buoyant materials. By integrating the underwater acoustic communication module and being equipped with the external erosion wearing release device, the MicrOBEMs make release and recovery possible using only a 17-inch glass sphere, thus greatly reducing the volume and hardware cost of the instrument and improving the integration and operation efficiency of devices. Compared to the OBEM-Ⅲ type, the volume, power consumption, and cost of the newly developed MicrOBEMs are reduced by 3/4, 2/3, and 1/2, respectively. A deep-water geomagnetic test was conducted in March 2021 in the southern South China Sea, preliminarily verifying the geomagnetic measurement function of the MicrOBEMs and reflecting that the MicrOBEMs have the advantages of small size, low power consumption, and low cost.
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[1] Constable S C. Marine electromagnetic induction studies[J]. Surveys in Geophysics, 1990, 11(2/3): 303-327.
[2] Naif S, Key K, Constable S, et al. Melt-rich channel observed at the lithosphere-asthenosphere boundary[J]. Nature, 2013, 495: 356-359.
[3] Ichiki M, Baba K, Toh H, et al. An overview of electrical conductivity structures of the crust and upper mantle beneath the northwestern Pacific, the Japanese Islands, and continental East Asia[J]. Gondwana Research, 2009, 16(3/4): 545-562.
[4] Johansen S E, Panzner M, Mittet R, et al. Deep electrical imaging of the ultraslow-spreading Mohns Ridge[J]. Nature, 2019, 567: 379-383.
[5] Worzewski T, Jegen M, Kopp H, et al. Magnetotelluric image of the fluid cycle in the Costa Rican subduction zone[J]. Nature Geoscience, 2011, 4(2): 108-111.
[6] Key K, Constable S, Liu L, et al. Electrical image of passive mantle upwelling beneath the northern East Pacific Rise[J]. Nature, 2013, 495: 499-502.
[7] 魏文博, 邓明, 温珍河, 等. 南黄海海底大地电磁测深试验研究[J]. 地球物理学报, 2009, 52(3):740-749.
[8] Wei W B, Deng M, Wen Z H, et al. Experimental study of marine magnetotellurics in southern Huanghai[J]. Chinese Journal of Geophysics, 2009, 52(3), 740-749.
[9] Key K W, Constable S C, Weiss C J. Mapping 3D salt using the 2D marine magnetotelluric method: Case study from Gemini Prospect, Gulf of Mexico[J]. Geophysics, 2006, 71(1): B17-B27.
[10] Constable S C. Review paper: Instrumentation for marine magnetotelluric and controlled source electromagnetic sounding[J]. Geophysical Prospecting, 2013, 61: 505-532.
[11] Quasar Federal System, QMax EM3[EB/OL].(2010-06)[2020-09]. http://quasarfs.com/downloads/QuasarGeo-QMax-EM3-Datasheet.pdf
[12] Ogawa K, Matsuno T, Ichihara H, et al. A new miniaturized magnetometer system for long-term distributed observation on the seafloor[J]. Earth Planets & Space, 2018, 70(1)111-119.
[13] Chen K, Deng M, Luo X, et al. A micro ocean-bottom E-field receiver[J]. Geophysics, 2017, 82(5): E233-E241.
[14] 陈凯, 景建恩, 赵庆献, 等. 海底可控源电磁接收机及其水合物勘查应用[J]. 地球物理学报, 2017, 60(11):4262-4272.
[15] Chen K, Jing J E, Zhao Q X, et al. Ocean bottom EM receiver and application for gas-hydrate detection[J]. Chinese Journal of Geophysics, 2017, 60(11):4262-4272.
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