Novel Methods for Near-Surface Hydrogeological Feature Enhancement from High-Resolution Airborne Magnetic Data

AbstractInterpretation of high resolution aeromagnetic data of Ilesha and its environs within the basement complex of the geological setting of Southwestern Nigeria was carried out in the study. The study area is delimited by geographic latitudes 7°30′–8°00′N and longitudes 4°30′–5°00′E. This investigation was carried out using Euler deconvolution on filtered digitised total magnetic data (Sheet Number 243) to delineate geological structures within the area under consideration. The digitised airborne magnetic data acquired in 2009 were obtained from the archives of the Nigeria Geological Survey Agency (NGSA). The airborne magnetic data were filtered, processed and enhanced; the resultant data were subjected to qualitative and quantitative magnetic interpretation, geometry and depth weighting analyses across the study area using Euler deconvolution filter control file in Oasis Montag software. Total magnetic intensity distribution in the field ranged from –77.7 to 139.7 nT. Total magnetic field intensities reveal high-magnitude magnetic intensity values (high-amplitude anomaly) and magnetic low intensities (low-amplitude magnetic anomaly) in the area under consideration. The study area is characterised with high intensity correlated with lithological variation in the basement. The sharp contrast is enhanced due to the sharp contrast in magnetic intensity between the magnetic susceptibilities of the crystalline and sedimentary rocks. The reduced-to-equator (RTE) map is characterised by high frequencies, short wavelengths, small size, weak intensity, sharp low amplitude and nearly irregular shaped anomalies, which may due to near-surface sources, such as shallow geologic units and cultural features. Euler deconvolution solution indicates a generally undulating basement, with a depth ranging from −500 to 1000 m. The Euler deconvolution results show that the basement relief is generally gentle and flat, lying within the basement terrain.

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Assessment of Geothermal Energy Potential of Ruwan Zafi, Adamawa State and Environs, Northeastern Nigeria, using High Resolution Airborne Magnetic Data

Current Research in Geoscience ◽

10.3844/ajgsp.2020.1.15 ◽

2020 ◽

Vol 10 (1) ◽

pp. 1-15

Author(s):

Ibe Stephen Onyejiuwaka ◽

Uche Kelvin Iduma

Keyword(s):

High Resolution ◽

Geothermal Energy ◽

Magnetic Data ◽

Energy Potential ◽

Airborne Magnetic

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A pseudo‐adaptive hum filter to suppress rotor noise in high‐resolution airborne magnetic data

10.1190/1.1816931 ◽

2002 ◽

Cited By ~ 1

Author(s):

Jianghai Xia ◽

William E. Doll ◽

Richard D. Miller ◽

T. Jeffrey Gamey

Keyword(s):

High Resolution ◽

Magnetic Data ◽

Rotor Noise ◽

Airborne Magnetic

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APPLICATION OF UNMANNED AERIAL VEHICLE AS A BASE MAP LAYER IN NEAR-SURFACE GEOPHYSICS

JURNAL GEOGRAFI ◽

10.24114/jg.v13i1.17818 ◽

2021 ◽

Vol 13 (1) ◽

pp. 26

Author(s):

Muhammad Yanis ◽

Aprilla Hasibuan Anggini ◽

Faisal Abdullah ◽

Muzakir Zainal ◽

Marwan Abubakar

Keyword(s):

Data Analysis ◽

High Resolution ◽

Good Condition ◽

Data Interpretation ◽

Research Area ◽

Magnetic Data ◽

Physical Parameters ◽

Large Area ◽

Near Surface ◽

Near Surface Geophysics

The Geophysical method is operated by using physical parameters above the surface to estimate the subsurface structures. In data interpretation, all 3D surveys, i.e., magnetic, gravity, magnetotelluric, and airborne, are required for geographical conditions in the research area. In a large area, global DEM data is used to explain the field condition, but for local measurement, the data is not efficient due to low resolution (15-30 m/px). This research uses UAV technology to produce a high-resolution topography in local Geophysical measurement (500 x 600 m). The survey was conducted to map the coal structure in the subsurface. UAV data were also compared to SRTM (30 m/px) and DEMNAS (8 m/px) as global topography. Based on data processing, the UAV topographic was have a high resolution of 2.5 cm/px. Comparison of UAV and magnetic data are able to explain a good condition of field measurement than a global DEM data, even in a relatively small area; outcrops of the coal (50x50 m) can show a good differences contrast of topography. Based on data analysis, we can conclude that UAV technology can interpret the geophysical data measured in a local area.Keywords: UAV, SRTM, Topography, Geophysical Interpretation.Metode Geofisika bekerja dengan memanfaatkan parameter fisis diatas permukaan untuk pendugaan struktur bawah permukaan. Dalam tahapan interpretasi data, semua pengukuran 3D Geofisika; magnetic, gravity, magnetotelluric, dan airbone sangat membutuhkan keadaan geografis lapangan. Pada area yang luas, data DEM global digunakan untuk menjelaskan deskripsi lapangan, namun untuk pengukuran dekat permukaan yang bersifat lokal, data ini tidaklah efesien, karena resolusi yang relative rendah (15 – 30 m/px). Kami menggunakan teknologi UAV untuk menghasilkan topografi resolusi tinggi pada area pengukuran Geofisika dengan luas 500 x 600 m, yang disurvei untuk pemetaan batubara dibawah permukaan. Data UAV juga dibandingkan dengan topografi global SRTM (30 m/px) dan DEMNAS (8 m/px). Hasil pengolahan data menunjukkan data UAV menghasilkan topografi dengan resolusi 2.5 cm/px. Hasil overlay UAV dengan Geofisika magnetik mampu menjelaskan deskripsi lapangan dengan sangat baik dibandingkan DEM global, bahkan pada area yang relative kecil seperti singkapan batuabara (50x50 m) dapat menunjukkan keadaan perbedaan topografi dengan kontras. Berdasarkan data analysis, topografi UAV sangat potensial digunakan untuk interpretasi data Geofisika dekat permukaan yang diukur pada area yang relative lokal.Kata kunci: UAV, SRTM, Topografi, Interpretasi Geofisika.

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First geophysical results in the Archeological sites of Θούρια (Péloponnèse, Hellas) and Sibari-Thurii (southern Italy)

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.16827 ◽

2018 ◽

Vol 40 (3) ◽

pp. 1080

Author(s):

B. Di Fiore ◽

D. Chianese ◽

A. Loperte ◽

G. Conte ◽

A. Dibenedetto ◽

...

Keyword(s):

High Resolution ◽

Information Quality ◽

Southern Italy ◽

Magnetic Measurements ◽

Early Stage ◽

Geophysical Methods ◽

Magnetic Data ◽

Near Surface ◽

Data Inversion ◽

Near Surface Geophysics

High resolution techniques for data acquisition and processing procedures are increasingly applied in near-surface geophysics for archaeology. In this paper we present the preliminary results of two geophysical measurements campaigns aimed to the investigation of buried remains in the archaeological sites of Θουρία (Péloponnèse, Hellas) and Sibari (Southern Italy). In the first field survey the geophysical approach involved the integrated application of the geoelectrical and magnetic methods and an innovative tomographic analysis for the inversion of both resistivity and magnetic data. In the second case, we carried out high resolution magnetic measurements, interpreted by means of the use of an appropriate filtering procedure. The applied data inversion allows us to provide reliable space patterns of the most probable specific target boundaries, improving the information quality of geophysical methods. The results obtained at this early stage of data processing confirm some archaeological hypothesis about the investigated areas and confirm that the use of integrated geophysical methods allows the archaeologists to reduce the time and the costs of their surveys.

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