Algorithm for Automatic Extraction of Lineaments from SAR Image Data

Abstract

This paper proposes a new method for the automatic extraction of the lineaments on the SAR (Synthetic Aperture Radar) image data. It is well known that the lineament patterns are the important feature reflect the structures of the subsurface.A lineament map has been drawn by the fieldworks of experts and the analysis of the enhanced image data using visual interpretation. It is therefore indicated that automatic extraction of the lineaments on the SAR image data is useful and effective for understanding the geological structure in the study area.This paper generates the edge data which contains the lineaments using some operators and template matching at first. Next, the emphasis of edge with the scored method is carried out. It is assumed that the edge pixel having high scored value can be much related to the lineaments. Finally, the trace and connection of the edge is conducted with the above assumption. As a result, it is confirmed that the results with the proposed method correspond to the lineament map drawn by experts. Therefore, it can be concluded that the proposed method is the effective technique for automatic extraction of the lineaments on the SAR image data.

Lineament detection from land cover information in mixels using Landsat‐TM data

“…The classification results due to fuzzy reasoning were applied to the edge data obtained by the above processing. Then, segments were extracted from the secondary edge data obtained by the lineament extraction method using the SAR data which we proposed earlier [7]. The examination in this paper was based on D.W. O'Leary's definition of lineaments [18].…”

“…For three types of elementary edge data, bands 1 through 4, band 5, and band 7, 60 different 7 × 7 templates (eight directions) and a 7 × 7 filter were used to compute score values [7]. It is possible to consider coordinate fuzziness when using these operators.…”

“…It is possible to consider coordinate fuzziness when using these operators. If the score values serve to connect the extracted edges, connection processing of the edges can be carried out using the resulting score values [7]. Finally, the target data were divided into small blocks and the Hough transform [21] was applied to each small block, allowing the creation of secondary edge data from the connected edges.…”

“…Also, different experts may extract different segments by visual observation [6]. In an earlier paper, we described a method for extracting lineaments using airborne Synthetic Aperture Radar (SAR) data [7]. It was found that the method was capable of extracting segments influenced by geological structures.…”

“…That is, land cover information in mixels is used as a feature for lineament extraction, and segments are then generated based on the previous techniques [7,14]. In order to examine the usefulness of the proposed method, we compare the results obtained by the proposed method with not only lineament maps given by visual interpretation [15] but also with results obtained by the previous method [14] and by the Directional Segment Detection Algorithm (DSDA) [13].…”