期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2010
卷号：XXXVIII - Part 7B
页码：181-186
出版社：Copernicus Publications
摘要：This study evaluates the performance of two fundamentally different approaches to achieve sub-pixel precision of normalised cross- correlation when measuring surface displacements on mass movements from repeat optical images. In the first approach, image intensities are interpolated to a desired sub-pixel resolution using a bi-cubic interpolation scheme prior to the actual displacement matching. In the second approach, the image pairs are correlated at the original image resolution and the peaks of the correlation coefficient surface is then located at the desired sub-pixel resolution using three techniques, namely bi-cubic interpolation, parabola fitting and Gaussian fitting. Both principal approaches are applied to three typical mass movement types: rockglacier creep, glacier flow and rock sliding. Their performance is evaluated in terms of matching accuracy and in reference to the images of the resolution they are expected to substitute. Our results show that intensity interpolation using bi-cubic interpolation (first approach) performs best followed by bi-cubic interpolation of the correlation surface (second approach). Both Gaussian and parabolic peak locating perform weaker. By increasing the spatial resolution of the matched images by intensity interpolation using factors of 2 to 16, 40% to 80% reduction in mean error could be achieved in reference to the same resolution original image
