Development and demonstration of a gravity gradiometer onboard an autonomous underwater vehicle for detecting massive subseafloor deposits
Development and demonstration of a gravity gradiometer onboard an autonomous underwater vehicle for detecting massive subseafloor deposits
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DOI：
10.1016/j.oceaneng.2015.06.008
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发表时间：
2015-09-01
影响因子：
5
通讯作者：
Tsukioka, S.
中科院分区：
文献类型：
--
作者：
Araya, A.;Shinohara, M.;Tsukioka, S.
重力测量用于探测地下密度结构。在这方面，使用重力仪和重力梯度仪的混合勘测配置特别有效。开发了一种重力梯度仪，用于对海底下大量矿床进行混合重力勘测。在使用自主水下航行器（AUV）的海洋试验中对其性能进行了评估。梯度仪由两个相同的垂直长周期陀螺组成，用作重力传感器，间距为0.44米。重力梯度仪的自噪声估计为6 E（6 × 10（-9）/s（2））（2-50 mHz），当AUV位于典型矿床存款上方时，可利用该噪声探测重力梯度信号。重力梯度仪安装在由光纤陀螺仪和倾斜仪垂直控制的强制万向节上。使用Urashima自主式潜水器（日本海洋技术研究所）在相模湾约1 300米深处进行的海洋试验观测表明，该系统在移动平台上稳定运行，但在转弯和俯仰等极端运动期间除外。由此产生的重力梯度受平台运动的影响很大，估计分辨率为3 x 102 E，这主要受到记录系统噪声的限制。(C)2015爱思唯尔有限公司版权所有。
Gravity surveys are used to detect underground density structures. Hybrid survey configurations using a gravimeter and a gravity gradiometer are particularly effective in this regard. A gravity gradiometer was developed for use in hybrid gravity surveys of massive subseafloor deposits. Its performance was evaluated in an ocean-based trial using an autonomous underwater vehicle (AUV). The gradiometer consisted of two identical vertical long-period pendulums, acting as gravity sensors, with a separation of 0.44 m. The self-noise of the gradiometer was estimated to be 6 E (6 x 10(-9)/s(2)) at 2-50 mHz, with which the gravity gradient signal could be detected when the AUV was above a typical ore deposit. The gravity gradiometer was mounted on a forced gimbal vertically controlled by fiber optic gyroscopes and tiltmeters. The ocean-based trial observation performed at a depth of approximately 1300 m in Sagami Bay using the AUV Urashima (JAMSTEC) showed that the system operated steadily on a moving platform except during periods of extreme motion, such as turning and pitching. The resulting gravity gradient was highly affected by the motion of the platform and the estimated resolution was 3 x 102 E, which was mainly limited by the noise of the recording system. (C) 2015 Elsevier Ltd. All rights reserved.