Weighted Euler deconvolution of gravity data

Geophysics ◽  
1998 ◽  
Vol 63 (5) ◽  
pp. 1595-1603 ◽  
Author(s):  
Pierre B. Keating
Keyword(s):  
Euler Equations ◽  
Gravity Data ◽  
Error Function ◽  
Bouguer Anomaly ◽  
Depth Estimation ◽  
Euler Deconvolution ◽  
Structural Index ◽  
Eastern Canada ◽  
Adequate Sampling

Euler deconvolution is used for rapid interpretation of magnetic and gravity data. It is particularly good at delineating contacts and rapid depth estimation. The quality of the depth estimation depends mostly on the choice of the proper structural index and adequate sampling of the data. The structural index is a function of the geometry of the causative bodies. For gravity surveys, station distribution is in general irregular, and the gravity field is aliased. This results in erroneous depth estimates. By weighting the Euler equations by an error function proportional to station accuracies and the interstation distance, it is possible to reject solutions resulting from aliasing of the field and less accurate measurements. The technique is demonstrated on Bouguer anomaly data from the Charlevoix region in eastern Canada.

scholarly journals Tensor deconvolution: A method to locate equivalent sources from full tensor gravity data

Geophysics ◽  
2007 ◽  
Vol 72 (5) ◽  
pp. I61-I69 ◽  
Author(s):  
Valentin Mikhailov ◽  
Gwendoline Pajot ◽  
Michel Diament ◽  
Antony Price
Keyword(s):  
Gravity Field ◽  
Gravity Data ◽  
Random Noise ◽  
Depth Estimation ◽  
Observation Point ◽  
Euler Deconvolution ◽  
Structural Index ◽  
Measuring Device ◽  
Equivalent Sources ◽  
Scalar Invariants

We present a method dedicated to the interpretation of full tensor (gravity) gradiometry (FTG) data called tensor deconvolution. It is especially designed to benefit from the simultaneous use of all the FTG components and of the gravity field. In particular, it uses tensor scalar invariants as a basis for source location. The invariant expressions involve all of the independent components of the tensor. This method is a tensor analog of Euler deconvolution, but has the following advantages compared to the conventional Euler deconvolution method: (1) It provides a solution at every observation point, without the use of a sliding window. (2) It determines the structural index automatically; as a consequence, the structural index follows the variations of the field morphology. (3) It uses all components of the measured full gradient tensor and gravity field, thus reducing errors caused by random noise. It is based on scalar invariants that are by nature insensitive to the orientation of the measuring device. We tested our method on both noise-free and noise-contaminated data. These tests show that tensor solutions cluster in the vicinity of the center of causative bodies, whereas Euler solutions better outline their edges. Hence, these methods should be combined for improved contouring and depth estimation. In addition, we use a clustering method to improve the selection of solutions, which proves advantageous when data are noisy or when signals from close causative bodies interfere.

scholarly journals Estimation of Depth to Bouguer Anomaly Sources Using Euler Deconvolution Techniques

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Gideon Oluyinka Layade ◽  
Hazeez Edunjobi ◽  
Victor Makinde ◽  
Babatunde Bada
Keyword(s):  
Bouguer Anomaly ◽  
Depth Estimation ◽  
Hydrocarbon Exploration ◽  
Survey Method ◽  
Depth Range ◽  
Euler Deconvolution ◽  
Structural Index ◽  
Geological Information ◽  
Geophysical Measurement ◽  
Deconvolution Techniques

Abstract The geophysical measurement of variations in gravitational field of the Earth for a particular location is carried out through a gravity survey method. These variations termed anomalies can help investigate the subsurface of interest. An investigation was carried out using the airborne satellite-based (EGM08) gravity dataset to reveal the geological information inherent in a location. Qualitative analysis of the gravity dataset by filtering techniques of two-dimensional fast Fourier transform (FFT2D) shows that the area is made up of basement and sedimentary Formations. Further enhancements on the residual anomaly after separation show the sedimentary intrusion into the study area and zones of possible rock minerals of high and low density contrasts. Quantitative interpretations of the study area by 3-D Euler deconvolution depth estimation technique described the depth and locations of gravity bodies that yielded the gravity field. The result of the depth to basement approach was found to be in the depth range of 930 m to 2,686 m (for Structural Index, SI = 0). The research location is a probable area for economic mineral deposits and hydrocarbon exploration.

scholarly journals Depth Estimation Using the Tilt Angle of Gravity Field due to the Semi-Infinite Vertical Cylindrical Source

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Ata Eshaghzadeh
Keyword(s):  
Tilt Angle ◽  
Gravity Data ◽  
Random Noise ◽  
Depth Estimation ◽  
Potential Fields ◽  
Source Depth ◽  
Euler Deconvolution ◽  
Deconvolution Technique ◽  
Cylindrical Source ◽  
Interpretation Method

Tilt angle filter is an interpretation method that is used to determine the source borders locations from potential fields data. Moreover, the tilt angle is applied for estimation of the anomaly source depth, such as contact-depth method and tilt-depth method. In this paper an application of the tilt angle technique obtained from the first vertical and horizontal gradients of the gravity anomaly from semi-infinite vertical cylindrical source is described. The technique is based on the tilt angle and derivatives ratio. In this approach the depth estimates are proportional to the computed tilt angles and their distances from the cross section center of the anomaly cause on the surface. This new method is termed the tilt-distance-depth (TDD). The method is demonstrated using synthetic gravity data, with and without random noise, and real gravity data from Iran. The results are also compared with the solutions from Euler deconvolution technique and inverse modelling using Modelvision software.

scholarly journals Basement Configuration Of Labuan Basin, Pandeglang, Based On Gravity Data

2020 ◽  
Vol 21 (2) ◽  
pp. 103
Author(s):  
Lina Handayani ◽  
Dadan Dani Wardhana
Keyword(s):  
Gravity Data ◽  
Bouguer Anomaly ◽  
Depth Estimation ◽  
Sediment Layer ◽  
Geological Hazards ◽  
Deep Basin ◽  
Geophysical Techniques ◽  
Gravity Measurements ◽  
Tectonically Active ◽  
Basement Depth

Pandeglang is located on the coast of the Sunda Strait, which is tectonically active as the source of geological hazards. Basement configuration mapping is required for further understanding in geological characteristic of the land. Gravity method is one of the geophysical techniques that can be applied for the regional subsurface characterization. Gravity measurements were completed in the Pandeglang area, from Tanjung Lesung to Labuan coastline and all passable roads in Pandeglang Regency. The Bouguer anomaly obtained has indicated a steady decreasing anomaly from south-southwest to north-northeast area. The result of residual anomalies analysis and basement depth estimation presented a deep basin in the northeast most of the study area (Labuan – Picung), which indicates a thick sediment layer in this area.Keywords: gravity anomaly, residual anomaly, basin, basement, Labuan, Pandeglang. 

scholarly journals Quality Assessment of 3D Synthesized Images Based on Textural and Structural Distortion Estimation

2021 ◽  
Vol 11 (6) ◽  
pp. 2666
Author(s):  
Hafiz Muhammad Usama Hassan Alvi ◽  
Muhammad Shahid Farid ◽  
Muhammad Hassan Khan ◽  
Marcin Grzegorzek
Keyword(s):  
Quality Assessment ◽  
Mixed Reality ◽  
Depth Estimation ◽  
Poor Quality ◽  
Depth Image ◽  
Depth Maps ◽  
Structural Distortions ◽  
Image Quality Metric ◽  
Technological Constraints

Emerging 3D-related technologies such as augmented reality, virtual reality, mixed reality, and stereoscopy have gained remarkable growth due to their numerous applications in the entertainment, gaming, and electromedical industries. In particular, the 3D television (3DTV) and free-viewpoint television (FTV) enhance viewers’ television experience by providing immersion. They need an infinite number of views to provide a full parallax to the viewer, which is not practical due to various financial and technological constraints. Therefore, novel 3D views are generated from a set of available views and their depth maps using depth-image-based rendering (DIBR) techniques. The quality of a DIBR-synthesized image may be compromised for several reasons, e.g., inaccurate depth estimation. Since depth is important in this application, inaccuracies in depth maps lead to different textural and structural distortions that degrade the quality of the generated image and result in a poor quality of experience (QoE). Therefore, quality assessment DIBR-generated images are essential to guarantee an appreciative QoE. This paper aims at estimating the quality of DIBR-synthesized images and proposes a novel 3D objective image quality metric. The proposed algorithm aims to measure both textural and structural distortions in the DIBR image by exploiting the contrast sensitivity and the Hausdorff distance, respectively. The two measures are combined to estimate an overall quality score. The experimental evaluations performed on the benchmark MCL-3D dataset show that the proposed metric is reliable and accurate, and performs better than existing 2D and 3D quality assessment metrics.

scholarly journals Gravity Analysis for Subsurface Characterization and Depth Estimation of Muda River Basin, Kedah, Peninsular Malaysia

2021 ◽  
Vol 11 (14) ◽  
pp. 6363
Author(s):  
Muhammad Noor Amin Zakariah ◽  
Norsyafina Roslan ◽  
Norasiah Sulaiman ◽  
Sean Cheong Heng Lee ◽  
Umar Hamzah ◽  
...  
Keyword(s):  
River Basin ◽  
Rock Type ◽  
Gravity Data ◽  
Power Spectral Analysis ◽  
Depth Estimation ◽  
Structural Features ◽  
Peninsular Malaysia ◽  
Gravity Survey ◽  
Basement Rock ◽  
Geophysical Techniques

Gravity survey is one of the passive geophysical techniques commonly used to delineate geological formations, especially in determining basement rock and the overlying deposit. Geologically, the study area is made up of thick quaternary alluvium deposited on top of the older basement rock. The Muda River basin constitutes, approximately, of more than 300 m of thick quaternary alluvium overlying the unknown basement rock type. Previous studies, including drilling and geo-electrical resistivity surveys, were conducted in the area but none of them managed to conclusively determine the basement rock type and depth precisely. Hence, a regional gravity survey was conducted to determine the thickness of the quaternary sediments prior to assessing the sustainability of the Muda River basin. Gravity readings were made at 347 gravity stations spaced at 3–5 km intervals using Scintrex CG-3 covering an area and a perimeter of 9000 km2 and 730 km, respectively. The gravity data were then conventionally reduced for drift, free air, latitude, Bouguer, and terrain corrections. These data were then consequently analyzed to generate Bouguer, regional and total horizontal derivative (THD) anomaly maps for qualitative and quantitative interpretations. The Bouguer gravity anomaly map shows low gravity values in the north-eastern part of the study area interpreted as representing the Main Range granitic body, while relatively higher gravity values observed in the south-western part are interpreted as representing sedimentary rocks of Semanggol and Mahang formations. Patterns observed in the THD anomaly and Euler deconvolution maps closely resembled the presence of structural features such as fault lineaments dominantly trending along NW-SE and NE-SW like the trends of topographic lineaments in the study area. Based on power spectral analysis of the gravity data, the average depth of shallow body, representing alluvium, and deep body, representing underlying rock formations, are 0.5 km and 1.2 km, respectively. The thickness of Quaternary sediment and the depth of sedimentary formation can be more precisely estimated by other geophysical techniques such as the seismic reflection survey.

scholarly journals Geometrical Characterisation of the Mamfe Basin, Cameroon, from the Earth, Gravitational Model (EGM 2008)

2018 ◽  
Vol 7 (1) ◽  
pp. 94
Author(s):  
Anatole Eugene Djieto Lordon ◽  
Mbohlieu YOSSA ◽  
Christopher M Agyingi ◽  
Yves Shandini ◽  
Thierry Stephane Kuisseu
Keyword(s):  
Average Length ◽  
Gravity Data ◽  
Bouguer Anomaly ◽  
Igneous Rocks ◽  
Average Depth ◽  
The Earth ◽  
Gravitational Model ◽  
Petroleum Generation ◽  
Anomaly Map ◽  
Bouguer Anomaly Map

Gravimetric studies using the ETOPO1-corrected high resolution satellite-based EGM2008 gravity data was used to define the surface extent, depth to basement and shape of the Mamfe basin. The Bouguer anomaly map was produced in Surfer 11.0. The Fast Fourier Transformed data was analyzed by spectral analysis to remove the effect of the regional bodies in the study area. The residual anomaly map obtained was compared with the known geology of the study area, and this showed that the gravity highs correspond to the metamorphic and igneous rocks while the gravity lows match with Cretaceous sediments. Three profiles were drawn on the residual anomaly map along which 2D models of the Mamfe basin were drawn. The modeling was completed in Grav2dc v2.06 software which uses the Talwini’s algorithm and the resulting models gave the depth to basement and the shape of the basement along the profiles. After processing and interpretation, it was deduced that the Mamfe basin has an average length and width of 77.6 km and 29.2 km respectively, an average depth to basement of 5 km and an overall U-shape basement. These dimensions (especially the depth) theoretically create the depth and temperature conditions for petroleum generation. 

scholarly journals Lineament Extraction using Gravity Data in the Citarum Watershed

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Gumilar Utamas Nugraha ◽  
Karit Lumban Goal ◽  
Lina Handayani ◽  
Rachmat Fajar Lubis
Keyword(s):  
Gravity Data ◽  
Bouguer Anomaly ◽  
High Density ◽  
Low Density ◽  
Residual Value ◽  
Satellite Gravity ◽  
Structural Weakness ◽  
Major Trend ◽  
Lineament Extraction ◽  
Butterworth Filters

Lineament is one of the most important features showing subsurface elements or structural weakness such as faults. This study aims to identify subsurface lineament patterns using automatic lineament in Citarum watershed with gravity data. Satellite gravity data were used to generate a sub-surface lineament. Satellite gravity data corrected using Bouguer and terrain correction to obtain a complete Bouguer anomaly value. Butterworth filters were used to separate regional and residual anomaly from the complete Bouguer anomaly value. Residual anomaly gravity data used to analyze sub-surface lineament. Lineament generated using Line module in PCI Geomatica to obtain sub-surface lineament from gravity residual value. The orientations of lineaments and fault lines were created by using rose diagrams. The main trends observed in the lineament map could be recognized in these diagrams, showing a strongly major trend in NW-SE, and the subdominant directions were in N-S. Area with a high density of lineament located at the Southern part of the study area. High-density lineament might be correlated with fractured volcanic rock upstream of the Citarum watershed, meanwhile, low-density lineament is associated with low-density sediment. The high-density fracture might be associated with intensive tectonics and volcanism.

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