Optimizing Image Scale and Resolution to Obtain Lineament Related Structures using ALOS PALSAR Dual Orbit Data

Abstract

Geological structures identification using conventional optical remote sensing encountered some problems due to atmospheric and surface conditions. Therefore, we exploited the Synthetic Aperture Radar (SAR) in Ascending and Descending orbits to characterize lineaments related to geological structures. We have analyzed two images from the Phased Array type L-band Synthetic Aperture Radar (PALSAR) onboard the Advanced Land Observing Satellite (ALOS). The adjustment of their resolution in the multilooking process was applied to obtain the best understanding between detected lineament and reference fault. The cross-polarized data of ALOS PALSAR level SLC were multilooked with variation of resolution from 15 to 120 m. Obtaining the optimum detected lineament-related faults, which applied the Yamaguchi criterion to extract the lineament visually in the multilooked images. The Kamojang-Guntur Geothermal Fields in West Java were selected as a study area because there is a challenge to confirm geological structure in the area with high alteration and high weathering conditions. According to the proposed criterion, we have obtained those images with resolution of 75 to 90 from the analysis images can represent surface geological structure conditions, and the correlation with existing published geological map. The field verifications have been confirmed that the geological structure indication from images has been proved with the existence of slickenside and morphological conditions such as drainage of rivers, ridges, and valleys. Based on lineaments, stress regimes, and field verifications, it was concluded that Yamaguchi criterion analysis with image resolution 75 to 90 m can describe the presence of regional structures and interpreted structures.