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1.
Recent advancements in geophysical exploration have been realized through reliably integrating unmanned aerial vehicle platforms with lightweight, high-resolution magnetometer payloads. Unmanned aerial vehicle aeromagnetic surveys can provide a contemporary data product between the two end-members of coverage and resolution attained using manned airborne and terrestrial magnetic surveys. This new data product is achievable because unmanned aerial vehicle platforms can safely traverse with magnetometer payloads at flight elevations closer to ground targets than manned airborne surveys, while also delivering an increased coverage rate compared to walking conventional terrestrial surveys. This is a promising new development for geophysical and mineral exploration applications, especially in variable terrains. A three-dimensional unmanned aerial vehicle aeromagnetic survey was conducted within the Shebandowan Greenstone Belt, northwest of Thunder Bay, Ontario, Canada, in July 2017. A series of two-dimensional grids (∼500 m × 700 m) were flown at approximate elevations of 35, 45 and 70 m above ground level using a Dà-Jiāng Innovations multi-rotor unmanned aerial vehicle (S900) and a GEM Systems, Inc., Potassium Vapour Magnetometer (GSMP-35U). In total, over 48 line-km of unmanned aerial vehicle aeromagnetic data were flown with a line spacing of 25 m. The collected aeromagnetic data were compared to a regional heliborne aeromagnetic survey flown at an elevation of approximately 85 m above the terrain, with a line spacing of 100 m, as well as a follow-up terrestrial magnetic survey. The first vertical derivative of the gathered unmanned aerial vehicle total magnetic field data was calculated both directly between each of the different flight elevations, and indirectly by calculating the values predicted using upward continuation. This case study demonstrates that low flight elevation unmanned aerial vehicle aeromagnetic surveys can reliably collect industry standard total magnetic field measurements at an increased resolution when compared to manned airborne magnetic surveys. The enhanced interpretation potential provided by this approach also aided in delineating structural controls and hydrothermal fluid migration pathways (a pair of adjacent shear zones) related to gold mineralization on site. These structural features were not clearly resolved in the regional manned airborne magnetic data alone, further demonstrating the utility of applying high-resolution unmanned aerial vehicle aeromagnetic surveys to mineral exploration applications. The conclusions and interpretations drawn from the unmanned aerial vehicle aeromagnetic data, coupled with historical data, were applied to make a new gold mineralization discovery on the site, assayed at 15.7 g/t. 相似文献
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Pauline Le Maire Lionel Bertrand Marc Munschy Marc Diraison Yves Géraud 《Geophysical Prospecting》2020,68(7):2307-2319
Magnetic measurements with an unmanned aerial vehicle are ideal for filling the gap between ground and airborne magnetic surveying. However, to obtain accurate aeromagnetic data, the compensation of magnetic effects of the unmanned aerial vehicle is a challenge. Typically, scalar magnetometers are towed several metres under the unmanned aerial vehicle to minimize its magnetic field. In this study, a fluxgate three-component magnetometer is attached 42 cm in front of the unmanned aerial vehicle at the tip of a composite pipe. Using a scalar calibration, the sensor can be calibrated, and the permanent and induced magnetic fields of the unmanned aerial vehicle can be compensated. The contributions of the magnetic measurements at different altitudes to the unmanned aerial vehicle results were tested over an area of 1 km² in the Northern Vosges Mountains. The area is located in a hamlet surrounded by a forest where few geological outcrops are observed. Three magnetic surveys of the same area are obtained at different altitudes: 100, 30 and 1 m above the ground. The unmanned aerial vehicle magnetic data are compared with a helicopter aeromagnetic survey at 300 m above the ground and a ground magnetic survey using upward continuations of the maps to compare the results. The magnetic maps (300, 100, 30 and 1 m above the ground) show very different magnetic anomaly patterns (e.g. amplitude, shape, wavelength and orientation). The magnetic data at different altitudes improve the understanding of the geology from the local to more general scales. 相似文献
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无人机遥感技术系统作为新时期应急救援装备是震后快速获取灾情信息的重要手段,随着无人机的智能化、轻量化的影像处理软件的迅猛发展,无人机领域的应用也越来越广泛。本文选取了辽宁大连城岭村作为实验地点,以大疆精灵4pro无人机获取的1个架次308张照片作为实验数据,选取Pix4D、smart3D、photoscan三款无人机影像处理软件,以处理流程、耗时、正射精度、三维建模等指标作为测试指标对三款软件开展对比研究工作。研究结果表明,小型消费级无人机在飞控系统下的测量精度可达厘米级,处理流程方面从简到难依次为Pix4D、photoscan、smart3D,耗时方面从短到长依次为Pix4D、photoscan、smart3D,正射(dom)精度从高到低依次为Pix4D、smart3D、photoscan,三维建模精度从高到低依次为smart3D、Pix4D、photoscan,该实验结果不仅为搭建地震应急前后方指挥部数据处理平台建设提供技术支撑,同时还对使用此类无人机做行业应用及飞行参数设置提供参考意义。 相似文献
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磁法勘探是一种常用的地球物理勘探方法，其中光泵磁力仪是国内外应用于航空和地面磁法测量最多的磁力仪器.为满足深部矿产资源勘查对高精度磁测设备的需求，本文开展了低噪声、宽量程的高性能数字氦光泵磁力仪关键技术研究，主要包括磁传感器探头优化设计和新型数字化环路设计两方面.首先通过深入分析影响氦光泵磁力仪灵敏度的主要决定因素，对磁传感器关键部件氦灯、氦室进行小型化技术研究，解决高性能氦泵源和原子气室等关键件的制作工艺，提高氦灯效率和氦吸收室的磁共振信号输出强度，制作出高性能、低噪声的小型化氦光泵探头.然后，针对常规模拟跟踪环路的局限性，通过数字化技术研究，采用FPGA、DSP、DDS、环路跟踪算法和信号处理软件等技术构成新型数字环路，弥补现有基于模拟跟踪环路技术的模拟式氦光泵磁力仪的不足，该数字环路降低了氦光泵磁力仪的电路噪声，增强了抗电磁干扰能力，并扩展了磁力仪的量程.本文通过小型探头和数字环路的技术设计，研制出高精度大量程的地面数字氦光泵磁力仪，并用于第三方测试.通过第三方测试证明：实测仪器的静态噪声小于4 pT，磁场测量范围为20000~100000 nT，梯度容限大于10000 nT/m. 相似文献
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本文将轨道车辆系统仿真成由车厢、转向架及轮轴所组成。车厢与转向架间有次悬吊系统,转向架与轮轴间则有主悬吊系统。数学模型的推导将考虑车辆横向、垂向、翻滚及摇摆方向的运动,将车辆仿真成三维具16个自由度的系统。本研究将探讨行驶高架桥梁的轨道车辆受地震激振时的响应和安全性,结果显示,移轨力及脱轨系数会随着地表加速度的增加而增加,而轨道不平整度及速度参数对脱轨系数及移轨力的影响不大。 相似文献
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将轨道车辆系统仿真成由车厢、转向架及轮轴所组成。车厢与转向架间有次悬吊系统，转向架与轮轴间则有主悬吊系统。数学模型之推导将考虑车辆横向、垂向、翻滚(roll)及摇摆(yaw)方向之运动，将车辆仿真成三维具16个自由度之系统。本研究将探讨行驶高架桥梁之轨道车辆受地震激振时，建立轨道车辆与高架桥相互耦合之动态数学模型。 相似文献
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利用无人机航空遥感获取的高精度数据构建DEM模型,结合谱元法数值模拟技术对青川县区域动力放大效应进行探索,并与汶川地震诱发的地震灾害进行耦合分析。结果显示,斜坡地形存在对地震动幅度和持续时间有明显的放大作用。虚拟地震作用下,在东山、狮子梁、桅杆梁地形突出部位均出现峰值加速度放大的现象。合成数据分析表明,这种放大效应具有一定方向性,具体表现为水平向放大大于垂向,南北向放大大于东西向。根据对比,模拟结果与实测分析结果较为吻合,可为进一步开展斜坡地震动力评价提供参考依据。 相似文献
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The development of an alkali vapour vehicle borne magnetometer providing very high resolution and a high sampling rate has called for reconsideration of interpretation procedures. With continuous profiling at ground level, the close proximity to near surface structures requires that the precise interpretation of geological boundaries be of paramount importance. Rapid digital recording also demands efficient data processing. Both these requirements can be met by the method described. Essentially the method reduces to a simple Hilbert transform of the magnetic profile. The calculation provides an extremely well defined position of the contact and accurate specification of the dip, strike, depth of overburden, and magnetic susceptibility parameters. Particular advantages are tolerance to high frequency noise, independence from a predetermined origin and baseline, and freedom from subjective judgements. 相似文献
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当前无人机频率域半航空电磁方法(SAEM)成为地球物理勘探中的新兴技术,该方法通过空中无人飞行器测量地面上单个或多个可控源的垂直磁场.本文为无人机频率域SAEM开发了三维反演程序,正演采用交错网格有限差分.由于无人机采集的数据量巨大,因此使用了有限内存拟牛顿法(LBFGS)实现快速的三维反演,以避免计算和存储巨大的灵敏度矩阵.为了提升无人机频率域SAEM的三维反演效果,本文进一步实现了无人机频率域SAEM与大地电磁(MT)的三维联合反演,并对联合反演实施了地震结构约束,结构约束采用交叉梯度法实现.MT可以增加勘探深度,而结构约束可以提高电磁法反演的分辨率.最后通过建立四个理论模型,证明了本文程序的有效性. 相似文献
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Raymond M. Caron Claire Samson Paul Straznicky Stephen Ferguson Luise Sander 《Geophysical Prospecting》2014,62(2):352-363
Carleton University and Sander Geophysics are developing an unmanned aircraft system (UAS) for aeromagnetic surveying. As an early indication of the expected performance of the unmanned aircraft system, a simulated unmanned aircraft system (sUAS) was built. The simulated unmanned aircraft system is a T‐shaped structure configured as a horizontal gradiometer with two cesium magnetometers spaced 4.67 m apart, which is the same sensor geometry as planned for the unmanned aircraft system. The simulated unmanned aircraft system is flown suspended beneath a helicopter. An 8.5 km2 area in the Central Metasedimentary Belt of the Grenville Province, near Plevna, Ontario, Canada, was surveyed with the simulated unmanned aircraft system suspended 50 m above ground. The survey site was chosen on the basis of its complex geological structure. The total magnetic intensity (TMI) data recorded were compared to that obtained during a conventional fixed‐wing survey and a ground survey. Transverse magneto‐gradiometric data were also recorded by the simulated unmanned aircraft system. The simulated unmanned aircraft system total magnetic intensity data have a higher resolution than the conventional fixed‐wing data and were found to have a similar resolution to that of the ground survey data. The advantages of surveying with the simulated unmanned aircraft system were: (1) the acquisition of a detailed data set free of gaps in coverage at a low altitude above the terrain and (2) substantial saving of time and effort. In the survey site, the 4.67 m simulated unmanned aircraft system gradiometer measured the transverse magnetic gradient reliably up to an altitude of 150 m above ground. 相似文献
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无人机地震灾情监测系统主要由无人机飞行平台、飞行控制系统、遥感系统、软件系统和无线电遥控系统等几部分组成,具有运行成本低、执行任务灵活性高等特点,是快速获取震后灾情信息的重要手段。结合四川高原山区的自然地理和气象条件,对无人机地震灾情监测系统在四川高原山区的应用进行了研究。该系统在高原山区的应用将在提升地震灾情现场勘查能力,迅速获取灾情信息,增加救灾工作的时效性,及为后期科学考察提供辅助信息等方面提供重要的技术支撑。 相似文献
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房屋建筑结构数据是了解房屋抗震设防能力的基础，获取房屋建筑结构信息具有重要的现实意义。本文在简单介绍无人机遥感系统、房屋建筑信息无人机遥感调查技术流程的基础上，以全国多地多架次飞行任务为应用实例，对无人机照片进行筛选、姿态匹配、照片拼接、纹理映射等处理，获取了房屋建筑密集区的正射镶嵌图和三维场景模型，然后对房屋建筑结构类型进行目视判读，并与地面调查的真实结果比对分析，计算得到目视判读的准确率为91.17%，Kappa系数为0.80。结果表明，轻小型无人机轻便灵活，获取的三维场景模型能有效、直观、准确地进行房屋建筑结构类型判定，可弥补传统实地调查的不足，为评估大范围建筑物的抗震能力提供重要的参考依据。 相似文献
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Robert J.P. Strick Philip J. Ashworth Gregory H. Sambrook Smith Andrew P. Nicholas James L. Best Stuart N. Lane Daniel R. Parsons Christopher J. Simpson Christopher A. Unsworth Jonathan Dale 《地球表面变化过程与地形》2019,44(4):953-972
Images from specially-commissioned aeroplane sorties (manned aerial vehicle, MAV), repeat unmanned aerial vehicle (UAV) surveys, and Planet CubeSat satellites are used to quantify dune and bar dynamics in the sandy braided South Saskatchewan River, Canada. Structure-from-Motion (SfM) techniques and application of a depth-brightness model are used to produce a series of Digital Surface Models (DSMs) at low and near-bankfull flows. A number of technical and image processing challenges are described that arise from the application of SfM in dry and submerged environments. A model for best practice is presented and analysis suggests a depth-brightness model approach can represent the different scales of bedforms present in sandy braided rivers with low-turbidity and shallow (< 2 m deep) water. The aerial imagery is used to quantify the spatial distribution of unit bar and dune migration rate in an 18 km reach and three ~1 km long reaches respectively. Dune and unit bar migration rates are highly variable in response to local variations in planform morphology. Sediment transport rates for dunes and unit bars, obtained by integrating migration rates (from UAV) with the volume of sediment moved (from DSMs using MAV imagery) show near-equivalence in sediment flux. Hence, reach-based sediment transport rate estimates can be derived from unit bar data alone. Moreover, it is shown that reasonable estimates of sediment transport rate can be made using just unit bar migration rates as measured from 2D imagery, including from satellite images, so long as informed assumptions are made regarding average bar shape and height. With recent availability of frequent, repeat satellite imagery, and the ease of undertaking repeat MAV and UAV surveys, for the first time, it may be possible to provide global estimates of bedload sediment flux for large or inaccessible low-turbidity rivers that currently have sparse information on bedload sediment transport rates. © 2018 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd. 相似文献
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G. Paschmann N. Sckopke H. Vaith J. M. Quinn O. H. Bauer W. Baumjohann W. Fillius G. Haerendel S. S. Kerr C. A. Kletzing K. Lynch C. E. McIlwain R. B. Torbert E. C. Whipple 《Annales Geophysicae》1999,17(12):1513-1520
We present the first electron time-of-flight measurements obtained with the Electron Drift Instrument (EDI) on Equator-S. These measurements are made possible by amplitude-modulation and coding of the emitted electron beams and correlation with the signal from the returning electrons. The purpose of the time-of-flight measurements is twofold. First, they provide the drift velocity, and thus the electric field, when the distance the electrons drift in a gyro period becomes sufficiently large. Second, they provide the gyro time of the electrons emitted by the instrument, and thus the magnitude of the ambient magnetic field, allowing in-flight calibration of the flux-gate magnetometer with high precision. Results of both applications are discussed. 相似文献
17.
Jing Liu-Zeng Wenqian Yao Xiaoli Liu Yanxiu Shao Wenxin Wang Longfei Han Yan Wang Xianyang Zeng Jinyang Li Zijun Wang Zhijun Liu Hongwei Tu 《地震研究进展（英文）》2022,2(2):100140
The 22 May 2021 MW 7.4 Madoi, Qinghai, China earthquake presented a rare opportunity to apply the modern unmanned aerial vehicle (UAV) photography method in extreme altitude and weather conditions to image surface ruptures and near-field effects of earthquake-related surface deformations in the remote Tibet. High-resolution aerial photographs were acquired in the days immediately following the mainshock. The complex surface rupture patterns associated with this event were covered comprehensively at 3–6 cm resolution. This effort represents the first time that an earthquake rupture in the interior of the Qinghai-Tibetan Plateau has been fully and systematically captured by such high-resolution imagery, with an unprecedented level of detail, over its entire length. The dataset has proven valuable in documenting subtle and transient rupture features, such as the significant mole-tracks and opening fissures, which were ubiquitous coseismically but degraded during the subsequent summer storm season. Such high-quality imagery also helps to document with high fidelity the fractures of the surface rupture zone (supplements of this paper), the pattern related to how the faults ruptured to the ground surface, and the distribution of off-fault damage. In combination with other ground-based mapping efforts, the data will be analyzed in the following months to better understand the mechanics of earthquake rupture related to the fault zone rheology, rupture dynamics, and frictional properties along with the fault interface. 相似文献
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A rotating side-scan sonar system was designed to make time-lapse sonographs of a circular area of the sea floor. To construct the system, the transducers of a commercial side-scan system (frequency 105 kHz; pulse length 0.1 ms; horizontal beam width 1°; vertical beam width 20°; beam depressed 10° with respect to horizontal) were mounted 2 m above the sea floor on a vertical shaft that had a rotation speed of 0.5 rpm.The radially collected sonar images are recorded linearly on a standard side-scan recorder. To convert the linear record to a radial record, the original moving record is photographed through a slit by a rotating camera, exposing a circular image on film.Records that are collected with this system offer several advantages over records that are collected with towed systems. Bottom features are presented in nearly true plan geometry, and transducer yaw, pitch, and roll are eliminated. Most importantly, repeated observations can be made from a single point, and bedform movements of <50 cm can be measured. In quiet seas the maximum useful range of the system varies from 30 m (for mapping ripples) to 200 m (for mapping 10-m wavelength sand waves) to 450 m or more (for mapping gravel patches). 相似文献
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FU Bo LI Zhi-qiang CHEN Jie FAN Xi-wei LI Xiao-li LI Tao YAO Yuan LIU Yao-hui 《地震地质》2018,40(3):672-684
In order to complete the field investigation to the 25 November 2016 Arketao MW6.6 earthquake, ultra-low altitude remote-sensing data were obtained from miniature unmanned aerial vehicle. The surface rupture surveying has important significance for earthquake research. This paper selects the macro-epicenter of Arketao as the study area. The pictures were obtained with DJI Phantom 3 professional input into the software, the Digital Elevation Model (DEM), Digital Orthophoto Map (DOM) were acquired based on photogrammetry method using the overlapped optical remote-sensing images of UAV. Using these data, we can identify surface ruptures that have vertical dislocation.
We selected six feature points and drew the elevation profile. In the elevation profile map, we chose smooth part of the surface rupture sides and obtained the trend line. A stable point in the surface rupture was selected and the abscissa of the point was taken into the equation of two straight lines. Then subtracting the results of the two equations, we can get the vertical dislocation of the surface rupture. On this basis, we chose six feature points and determined their vertical dislocation, which are between 4.4cm and 10.4cm. What's more, taking Bulungkou Xiang in Xinjiang Uygur Autonomous Region for example, we speculated some surface ruptures that have vertical dislocation. It can provide a new method for identifying surface rupture in the field.
In addition, we get DEM data of the Bulunkou area where ambient conditions are very poor, by using miniature unmanned aerial vehicle and taking 255 photos. Putting those photos into the EasyUAV software, we got the area digital elevation of 2cm resolution. Comparing these data with RTK data, we summarized some practical problems and solutions in the practical operation and evaluated the accuracy of miniature unmanned aerial vehicle data. The Pearson Correlation Coefficient is 0.996 6. In terms of absolute elevation, the average result of UAV and RTK differs by 156.96m. In terms of relative elevation, the average result of UAV and RTK differs by 9.74m. Compared with the previous test of Pishan County, there is a notable divergence in the results. It shows that the data accuracy will be affected to some extent in the cold weather in high elevations. The specific impact needs further exploration. 相似文献
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Results of synchronous recording magnetic variations and seismic vibrations caused by an earthquake with a magnitude M = 6.7 at a distance of 806 km from the observation site are considered. Measurements are carried out at the VLA observatory.
Different patterns of seismic noise generation and their contributions to the magnetic variations recorded by torsion magnetometer
are analyzed. As well, the correlation between the seismic and magnetic components is studied. The close correlation between
the seismic accelerations of rocks and the magnetic variations is revealed, and its transfer coefficient is estimated. Such
correlation in other types of magnetometers is supposed to hinder the measurement of seismomagnetic signals, which will require
the seismic noise parameters to be known for different types of magnetometers. 相似文献