Werner deconvolution, like Euler deconvolution, is more properly thought of as an inverse method: we analyze the observed magnetic field and solve for.

Slides:



Advertisements
Similar presentations
Can we use total field magnetics to find buried pit houses beneath layers of volcanic ash? Visible pit houses at Bridge River, B.C. (Prentiss et al., 2009)
Advertisements

Newton’s Laws and two body problems
M 1 and M 2 – Masses of the two objects [kg] G – Universal gravitational constant G = 6.67x N m 2 /kg 2 or G = 3.439x10 -8 ft 4 /(lb s 4 ) r – distance.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Analytical Expressions for Deformation from an Arbitrarily Oriented Spheroid in a Half- Space U.S. Department of the Interior U.S. Geological Survey Peter.
1-1 Copyright © 2015, 2010, 2007 Pearson Education, Inc. Chapter 21, Slide 1 Chapter 21 Comparing Two Proportions.
Gravitational Attractions of Small Bodies. Calculating the gravitational attraction of an arbitrary body Given an elementary body with mass m i at position.
Magnetic Methods (IV) Environmental and Exploration Geophysics I
Edge Detection and Depth Estimates – Application to Pseudogravity and Reduced to Pole Results: Part I Edge detection on an oversampled synthetic anomaly.
Mapping Basement Structure in East-Central New York Pearson, deRidder and Johnson, Inc.
EARS1160 – Numerical Methods notes by G. Houseman
1-1 Copyright © 2015, 2010, 2007 Pearson Education, Inc. Chapter 18, Slide 1 Chapter 18 Confidence Intervals for Proportions.
Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and Geography West Virginia University Morgantown,
Processing and interpreting total field magnetic data, Kevin Rim, Montana Collected three adjacent grids Grid #1 used for organization- fill in details.
Motion Analysis Slides are from RPI Registration Class.
GG 313 Geological Data Analysis # 18 On Kilo Moana at sea October 25, 2005 Orthogonal Regression: Major axis and RMA Regression.
The use of curvature in potential-field interpretation Exploration Geophysics, 2007, 38, 111–119 Phillips, Hansen, & Blakely Abstract. Potential-field.
INVERSIONS AND CONSTRAINTS
The Basics of Earthquake Location William Menke Lamont-Doherty Earth Observatory Columbia University.
Rutherford Backscattering Spectrometry
Gravity: Gravity anomalies. Earth gravitational field. Isostasy. Moment density dipole. Practical issues.
GG313 Lecture 3 8/30/05 Identifying trends, error analysis Significant digits.
Anatomy of Anomalies Total Field Magnetics and Ground Penetrating Radar at a Potential Archaeological Site.
Subgrade Models for Rigid Pavements. Development of theories for analyzing rigid pavements include the choice of a subgrade model. When the chosen model.
CSCI 347 / CS 4206: Data Mining Module 04: Algorithms Topic 06: Regression.
Outline  Derivatives and transforms of potential fields  First and second vertical derivatives  Convolutional operators  Fourier approach  Reduction.
GG 450 Feb 21, 2008 Magnetic Interpretation. Homework return.
Outline  Uses of Gravity and Magnetic exploration  Concept of Potential Field  Conservative  Curl-free (irrotational)  Key equations and theorems.
Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and Geography West Virginia University Morgantown, WV.
Ch 8.1 Numerical Methods: The Euler or Tangent Line Method
The aim of the presented research activities Is to develop new interpretation techniques for potential fields exploration methods (gravity, magnetic,
Gravity I: Gravity anomalies. Earth gravitational field. Isostasy.
Gravity Methods (IV) Environmental and Exploration Geophysics II
Body Waves and Ray Theory
Geology 5640/6640 Introduction to Seismology 10 Apr 2015 © A.R. Lowry 2015 Last time: Reflection Data Processing Source deconvolution (like filtering methods)
Lecture 12 Stereo Reconstruction II Lecture 12 Stereo Reconstruction II Mata kuliah: T Computer Vision Tahun: 2010.
16-1 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Croucher, Introductory Mathematics and Statistics, 5e Chapter 16 The.
Copyright © Cengage Learning. All rights reserved. Logarithmic Function Modeling SECTION 6.5.
FUNCTIONS AND MODELS 1. In this section, we assume that you have access to a graphing calculator or a computer with graphing software. FUNCTIONS AND MODELS.
Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and Geography West Virginia University Morgantown, WV.
CS654: Digital Image Analysis Lecture 8: Stereo Imaging.
Polynomial Equivalent Layer Valéria C. F. Barbosa* Vanderlei C. Oliveira Jr Observatório Nacional.
Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and Geography West Virginia University Morgantown, WV.
Nettleton, 1971 Note that a particular anomaly, such as that shown below, could be attributed to a variety of different density distributions. Note also,
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Jayne Bormann and Bill Hammond sent two velocity fields on a uniform grid constructed from their test exercise using CMM4. Hammond ’ s code.
GG 450 Feb 27, 2008 Resistivity 2. Resistivity: Quantitative Interpretation - Flat interface Recall the angles that the current will take as it hits an.
Environmental and Exploration Geophysics II t.h. wilson Department of Geology and Geography West Virginia University Morgantown, WV.
Geology 5660/6660 Applied Geophysics 11 Apr 2014 © A.R. Lowry 2014 For Mon 14 Apr: Burger (§ ) Last Time: DC Electrical Resistivity Modeling.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
A table of diagnostic positions and depth index multipliers for the Sphere (see your handout). Note that regardless of which diagnostic position you use,
The Rayleigh-Taylor Instability By: Paul Canepa and Mike Cromer Team Leftovers.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Scaling Gas-filled Muon Ring Coolers Al Garren, UCLA Ringcooler Mini-workshop Tucson, December 15-16, 2003.
Edge Detection and Depth Estimates – Application to Pseudogravity and Reduced to Pole Results: Part I Edge detection on an oversampled synthetic anomaly.
Ellipsometer B 許恭銓. Problem Overview We have a thin layer of oxide on a Si substrate and we want to find its thickness by using an ellipsometer.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Gravity Data Reduction
Hanyang University Antennas & RF Devices Lab. ANTENNA THEORY ANALYSIS AND DESIGN Prof. Jaehoon Choi Dept. of Electronics and Computer Engineering
EEE 431 Computational Methods in Electrodynamics
Collected three adjacent grids
Magnetic method Magnetic force and field strength for pole strength m’ and m.
Outline Uses of Gravity and Magnetic exploration
GG 450 February 19, 2008 Magnetic Anomalies.
Outline Derivatives and transforms of potential fields
Topic 8 Pressure Correction
Presentation transcript:

Werner deconvolution, like Euler deconvolution, is more properly thought of as an inverse method: we analyze the observed magnetic field and solve for source parameters. The initial assumption for total field analysis is thin, sheet like bodies. But that anomaly is equal to the horizontal gradient of the total field anomaly over a semi- infinite half space. Thus, Werner deconvolution is applied to dikes and layers and has been extended to polygons. The general equation over an inclined sheet of dipoles is: The unknowns are: xo = source location d = source depth A & B are combinations of constants, magnetization, and dip. We rewrite this as a matrix equation and, given four observed points on a magnetic profile, we have four equations in four unknowns.

Werner deconvolution is a ‘sliding window’ technique. We move the operator along the profile and continually solve for the unknowns. The figures show solutions for depth and location from sliding window step-sizes ranging from one grid unit to nine. Window lengths either too short or long yield spurious solutions. Note the solutions from the shortest operators.

Selecting the solutions from operator ranges which show the best clustering regularly yields good estimates.

Interfering anomalies complicate the issue. Yet, there is still good clustering over the tops of the dikes. As before, removing the solutions with poor clustering improves the situation.

Selecting the best clustered solutions yields improved results. Yet, there are still spurious solutions from the interference of the two anomalies. And, these anomalies have no geologic nor measurement error. Regardless of these difficulties, the Werner method is time-tested and yields valuable information for further analysis and modeling, particularly when the assumptions for the thin sheet or half-space conditions are met.

Here’s what can happen when you make the wrong assumption on the type of source. These are Werner solutions for the horizontal derivative of the dike anomaly. Analyzing the horizontal derivative is the procedure for estimating source parameters for the vertical contact of a semi-infinite half space. Clearly, the choice of an incorrect model results in lesser solutions. The recommended approach is to use both procedures, look carefully at clustering, compare the results to other techniques, and consider the actual anomalies.

The prism in this example is somewhere in between a thin dike and a semi- infinite half space. It is much thicker then deep, but the anomalies from the edges (contacts) still overlap over the center. When actually assessing clusters, it helps to use no vertical or horizontal exaggeration. Here, the edge detection of the best clustering is still good, but the depth estimates are too deep.

Assuming vertical contacts and thus calculating Werner solutions on the horizontal derivative still yields scattered solutions for short window lengths.

Even with interference from the insufficiently separated lateral edges, the clustered solutions provide good guidance for modeling.