REPORT OF THE SEG COMMITTEE FOR A NATIONAL MAGNETIC ANOMALY MAP

Geophysics ◽  
1976 ◽  
Vol 41 (5) ◽  
pp. 1055-1055
Keyword(s):  
Magnetic Field ◽  
Magnetic Anomaly ◽  
Developed Countries ◽  
Magnetic Survey ◽  
Accurate Representation ◽  
Anomalous Magnetic Field ◽  
Anomaly Map ◽  
The U.S ◽  
Airborne Magnetic ◽  
Airborne Magnetic Survey

Our country’s urgent need to find new sources for minerals and energy and its need to know more about the planet on which we live could be greatly assisted by preparation of a national magnetic anomaly map (NMAM)—a map which will provide an accurate representation of the earth’s anomalous magnetic field. It is startling to note that the U.S. is one of the few developed countries which has not commissioned a detailed airborne magnetic survey of the whole country, followed by production of a national magnetic anomaly map.

Cancellation of Dynamic ON/OFF Effects in Airborne Magnetic Survey

2017 ◽  
Vol 18 (1) ◽  
Author(s):  
Bassant Abdelhamid ◽  
Mohamed Elkattan
Keyword(s):  
Magnetic Survey ◽  
Airborne Magnetic ◽  
Airborne Magnetic Survey

Analysis of the Czech magnetic anomaly data obtained by ground-based and airborne magnetic surveys

2020 ◽  
Author(s):  
Pavel Hejda ◽  
Dana Čápová ◽  
Eva Hudečková ◽  
Vladimír Kolejka
Keyword(s):  
Magnetic Anomaly ◽  
Magnetic Anomalies ◽  
Data File ◽  
Ore Deposits ◽  
Substantial Contribution ◽  
Magnetic Survey ◽  
Contour Maps ◽  
Anomaly Map ◽  
Ground Magnetic ◽  
Airborne Survey

<p>The modern epoch of ground magnetic surveying activity on the Czech territory was started by the Institute of Geophysics by setting up a fundamental network of the 1<sup>st</sup> order in 1957-58. It consists of 199 points and was reoccupied in 1976-78 and 1994-96. The anomaly maps were constructed by subtraction of the IGRF model.</p><p>Extensive aeromagnetic measurements have been performed from 1959 to 1972 by permalloy probe of Soviet provenience. The accuracy of the instrumentation was about (and often above) 10 nT. The second period of airborne survey started in 1976. Thanks to the deployment of proton precession magnetometer, the accuracy improved to ~ 2 nT. Since 2004 the measurements were carried out by caesium magnetometer. The data were digitized, known anthropogenic anomalies were cleared away and data were transformed to the regular grid with step 250 m. The final data file of magnetic anomalies ΔT, administered by the Czech Geological Survey, represents a substantial contribution to the exploration of ore deposits and to the structure geology in general.</p><p>In view of the fact that data file of magnetic anomalies was compiled from data acquired by heterogeneous methods in the course of more than 50 years, our recent study is aimed at looking into the homogeneity of the data by comparison them with ground-based magnetic survey. A simple comparison of the contour maps showed good similarity of the large regional anomalies. For more detailed analysis, the variation of ΔT in the neighbourhood of all points of the fundamental network was inspected and the basic statistic characteristics were computed. Summary results as well as several examples will be presented accordingly as the INSPIRE compliant services and eventually as the user-friendly web map application and made available on the CGS Portal http://mapy.geology.cz/ and on the updated web of the CzechGeo/EPOS consortium www.czechgeo.cz. Incorporating the map into the World Digital Magnetic Anomaly Map (WDMAM – IAGA) is also under consideration. This data will also be interesting for the EPOS.</p>

scholarly journals Experiments on magnetic interference for a portable airborne magnetometry system using a hybrid unmanned aerial vehicle (UAV)

2020 ◽  
Author(s):  
Jirigalatu Jirigalatu ◽  
Vamsi Krishna ◽  
Eduardo Lima Simões da Silva ◽  
Arne Døssing
Keyword(s):  
Early Stage ◽  
Longitudinal Axis ◽  
Small Scale ◽  
Magnetic Survey ◽  
Stage Of Development ◽  
Rapid Sampling ◽  
Dynamic Experiments ◽  
Static Experiment ◽  
Airborne Magnetic ◽  
Airborne Magnetic Survey

Abstract. Airborne magnetic surveys are an important and efficient tool for mapping the subsurface, providing insights e.g. into mineral deposits. Compared to traditional ground methods, airborne magnetic surveys offer great advantages with improved access and rapid sampling. But the cost and hassle of transporting and operating a conventional manned airborne magnetic survey system are strong impediments for its wider use. In addition, the conventional airborne systems are challenged by the need for low-altitude (≤ 80 m) surveying to detect small-scale subsurface features evident in ground surveys. Portable and compact airborne magnetic survey systems using unmanned aerial vehicles (UAVs) can not only bridge the gap between conventional airborne magnetic surveys and ground magnetic surveys but also complement magnetic surveys to fit broader geophysical applications. Therefore, developing high-quality, stable, and portable UAV-borne survey systems is of high interest to the geophysical exploration community. However, developing such a system is challenging owing to strong magnetic interference introduced by onboard electric engines and other onboard electronic devices. As a result, tests concerning the static and dynamic magnetic interference of a UAV are critical to assess the severity of the interference and can help to improve the design of the system at the early stage of development. A static experiment and two dynamic experiments were conducted to understand the characterization of the magnetic interference of our hybrid vertical take-off and landing (VTOL) UAV. The results of the static experiment show that the wing area is highly magnetic due to the proximity to servomotors and motors, but the area along the longitudinal axis of the UAV is relatively magnetically quiet. To reduce the magnetic signature, the highly-magnetic servomotors on the wings were replaced with less magnetic servomotors of a brush-less type. Assisted by aerodynamic simulations, we further designed a front-mounting solution for two compact magnetometers. Two dynamic experiments were conducted with this setup to understand the dynamic interference of the UAV in operation. The results of the dynamic experiments reveal that the strongest source of in-flight magnetic interference is mainly due to the cables connecting the battery to the flight controller and that this effect is most influential during pitch maneuvers of the aircraft.

scholarly journals Airborne Magnetic Survey Applied for Civil Construction Purpose

1973 ◽  
Vol 14 (1-2) ◽  
pp. 21-26
Author(s):  
K. Ikeda ◽  
S. Matsuo ◽  
U. Mochida ◽  
T. Tsuchiya ◽  
K. Hasegawa
Keyword(s):  
Magnetic Survey ◽  
Construction Purpose ◽  
Airborne Magnetic ◽  
Airborne Magnetic Survey

Influence of systematic error on the magnetic anomaly map in marine magnetic survey

2014 ◽  
Author(s):  
Gang Bian ◽  
Wei Xia ◽  
Shaohua Jin ◽  
Xinxuan Sun ◽  
Yang Cui ◽  
...  
Keyword(s):  
Systematic Error ◽  
Magnetic Anomaly ◽  
Magnetic Survey ◽  
Anomaly Map

UAV magnetic survey for geological exploration: A case study of the Synnyr Massif, Buryatia, Russia

2020 ◽  
Author(s):  
Igor Maev ◽  
Anastasiya Karaman ◽  
Alexander Kajukov
Keyword(s):  
Magnetic Field ◽  
Field Measurements ◽  
Geophysical Survey ◽  
Fault System ◽  
Magnetic Data ◽  
Alkaline Magmatism ◽  
Magnetic Survey ◽  
Magnetic Field Measurements ◽  
Airborne Magnetic ◽  
Made In

<p>The Synnyr alkaline massif is a concentrically zoned body located in the Baikal Vitim folded area, Holodninskiy graben. It is controlled by the deep-seated Precambrian Baikal-Synnyr fault, while major rock types of the massif were dated as 230-350 Ma (Kostuk et al., 1990; Mitrofanova 2009). However, there were no young strike-slip faults or thrusts identified throughout the massif. Studying the area is compounded by the climate and landscape conditions, which makes the airborne geophysical survey a very cost-effective mapping tool. Main geological investigations of the Synnyr massif were made in the 1960s and in the 1980s. In those times, an airborne geophysical survey was not as accurate as it was required and didn’t bring up any significant results.</p><p>The next stage of Synnyr massif exploration began in 2016. The first airborne magnetic survey based on unnamed aerial vehicles (UAV) was made in 2018 and increased our knowledge about the geological situation in the studying area. Main goals of the UAV magnetic survey were tracing highly magnetic foidal gabbroids named shonkinites, which are located in the central part of the ore zone, and mapping major faults.</p><p>The airborne geophysical complex included a multirotor aerial vehicle and quantum magnetometer with a rubidium magnetic field sensor that was placed in the special gondola and attached to the UAV. The study area was surveyed at 20 meters height with detailed terrain following and accuracy of magnetic field measurements comparable with the ground magnetic survey.</p><p>As a result, airborne magnetic data helped to clarify geological structure and tectonics in the areas covered with glacier or without any outcrops. Furthermore, magnetic field measurements allowed to locate faults and lineaments which were not traced in previous geological studies of the Synnyr massif and to make an assumption about the neotectonic activity of Baikal-Synnyr fault system.</p><p>Due to cost-efficiency, informativeness and high accuracy of geophysical surveys based on UAV, we are planning to continue research and extend the studying area.</p><p>References:</p><p>Mitrofanova N.N. Report for Aldan-Transbaikal geological maps, 2009</p><p>Kostuk V.P., Panina L.I., Zhidkov A. Y., Orlova M.P., Bazarova T.Y. Potassium alkaline magmatism in Baikal-Stanovoi rift system, 1990</p>

U.S. National Magnetic Anomaly Survey Specifications Workshop Report

Geophysics ◽  
1979 ◽  
Vol 44 (5) ◽  
pp. 991-992
Author(s):  
William J. Hinze
Keyword(s):  
Magnetic Anomaly ◽  
North American ◽  
Executive Committee ◽  
Ad Hoc ◽  
Magnetic Data ◽  
Aeromagnetic Data ◽  
Workshop Report ◽  
The North ◽  
Anomaly Map ◽  
The U.S

The National Magnetic Anomaly Map (NMAM) Committee, which was formed as an ad hoc committee in 1975 by the SEG Executive Committee, has recommended a multistage program for improving the aeromagnetic data of the U.S. On behalf of the geoscience community, the committee and the U.S. Geological Survey are currently engaged in the preparation of a photo‐composite map of the U.S. derived from publicly available data plus regional magnetic data contributed from the private sector. This map is at present being compiled and is to be pulished by the U.S.G.S. at a scale of [Formula: see text]. Eventually, utilizing this map, the committee plans to assist in the preparation of a North American magnetic anomaly map to supplement the North American tectonic map and the proposed continental gravity anomaly map.

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