An Adaptive Offset Tracking Method with SAR Images for Landslide Displacement Monitoring

Abstract

Abstract:With the development of high-resolution Synthetic Aperture Radar (SAR) systems, researchers are increasingly paying attention to the application of SAR offset tracking methods in ground deformation estimation. The traditional normalized cross correlation (NCC) tracking method is based on regular matching windows. For areas with different moving characteristics, especially the landslide boundary areas, the NCC method will produce incorrect results. This is because in landslide boundary areas, the pixels of the regular matching window include two or more types of moving characteristics: some pixels with large displacement, and others with small or no displacement. These two kinds of pixels are uncorrelated, which result in inaccurate estimations. This paper proposes a new offset tracking method with SAR images based on the adaptive matching window to improve the accuracy of landslide displacement estimation. The proposed method generates an adaptive matching window that only contains pixels with similar moving characteristics. Three SAR images acquired by the Jet Propulsion Laboratory's Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) system are selected to estimate the surface deformation of the Slumgullion landslide located in the southwestern Colorado, USA. The results show that the proposed method has higher accuracy than the traditional NCC method, especially in landslide boundary areas. Furthermore, it can obtain more detailed displacement information in landslide boundary areas.

Kinematic Parameter Inversion of the Slumgullion Landslide Using the Time Series Offset Tracking Method With UAVSAR Data

“…The offset tracking method, which uses a pair of SAR intensity images to estimate the range and azimuth offsets by image patch matching, is widely applied to monitor coseismic displacement (Fialko et al, 2005;Fielding et al, 2013), glaciers (Pritchard et al, 2005;Strozzi et al, 2002), landslides (Shi et al, 2015), and volcanoes (Casu et al, 2011). In this paper, an offset tracking method based on adaptive normalized cross correlation (ANCC) is utilized to estimate the displacements of the landslide (Cai et al, 2017). The ANCC method estimates offset fields by calculating an adaptive normalized cross-correlation surface to evaluate the similarity between two SAR images and identifying the best matching position.…”

Quantitative Assessment of Digital Image Correlation Methods to Detect and Monitor Surface Displacements of Large Slope Instabilities

“…Ref. [15] further report correlation issues in areas with different moving characteristics, such as landslide boundary areas. Ref.…”

“…The application of remote sensing techniques enables also the extraction of information about the evolution of the slope instability. Within the last decade, air-and spaceborne remote sensing methods using active sensors, such as differential synthetic aperture radar (SAR) interferometry (DInSAR) [5,10,11], or methods using input from passive sensors, such as digital image correlation (DIC) [12][13][14][15][16], have been established to detect and monitor surface displacements at regional scales.…”

“…DIC, also known as feature-tracking or subpixel offset [15], is an image processing technique that identifies and quantifies ground displacement occurring orthogonal to the line-of-sight (LOS) of the camera [17]. Amongst others, DIC has been applied to monitor the glacier velocities [18,19], the ground displacement caused by earthquakes or tectonic activity [17,20], and the deformations at volcanoes [21].…”

Monitoring Surface Deformation over a Failing Rock Slope with the ESA Sentinels: Insights from Moosfluh Instability, Swiss Alps

“…This problem arises when a large deformation gradient affects relatively small areas, a characteristic scenario for slope instabilities evolving towards failure [9]. Several authors have proposed to overcome this limitation by analyzing the amplitude information of SAR images with Digital Image Correlation (DIC) techniques [12][13][14][15].…”