Separation of magnetic-field data using the differential Markov random-field (DMRF) approach


Albora A. M. , UÇAN O. M.

GEOPHYSICS, cilt.71, 2006 (SCI İndekslerine Giren Dergi)

  • Cilt numarası: 71 Konu: 2
  • Basım Tarihi: 2006
  • Doi Numarası: 10.1190/1.2187773
  • Dergi Adı: GEOPHYSICS

Özet

In this paper, the differential Markov random-field (DMRF) method is introduced and applied to the magnetic anomaly separation problem, in which residual anomalies are separated from a regional field. The DMRF method is all unsupervised statistical model-based learning approach that does not require prior knowledge. A data-adaptive program, based on the evaluation of noise and superimposed effects of various geologic structures, is presented by considering a statistical maximum a posteriori (MAP) criterion. The aim of our method is to capture the intrinsic properties of geologic structures and then to identify and hence understand the behavior of the observed magnetic-anomaly map. The magnetic-anomaly map is modeled using a 2D matrix. In the DMRF approach, each pixel of the matrix is evaluated considering neighboring pixels. In synthetic models, anomalies of magnetic dipoles are tested for different depths, orientation angles, and lengths.

 

In this paper, the differential Markov random-field
(DMRF) method is introduced and applied to the magnetic
anomaly separation problem, in which residual
anomalies are separated from a regional field. The
DMRF method is an unsupervised statistical modelbased
learning approach that does not require prior
knowledge. A data-adaptive program, based on the
evaluation of noise and superimposed effects of various
geologic structures, is presented by considering a statistical
maximum a posteriori (MAP) criterion. The aim of
our method is to capture the intrinsic properties of geologic
structures and then to identify and hence understand
the behavior of the observed magnetic-anomaly
map. The magnetic-anomaly map is modeled using a 2D
matrix. In the DMRF approach, each pixel of the matrix
is evaluated considering neighboring pixels. In synthetic
models, anomalies of magnetic dipoles are tested for different
depths, orientation angles, and lengths.
The DMRF method also is applied to the vertical
magnetic-anomaly map of the Sivas-Divrigi region in
Turkey, which contains the Dumluca iron ore reserves.
Shallow reserves are detected clearly by the DMRF
method, proving greater accuracy than classical filtering
techniques. The results are confirmed by Technical Ore
Research of Turkey (MTA) drilling reports.