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Báo cáo hóa học: " Fast correlation technique for glacier flow monitoring by digital camera and space-borne SAR images"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : Fast correlation technique for glacier flow monitoring by digital camera and space-borne SAR images | Vernier et al. EURASIP Journal on Image and Video Processing 2011 2011 11 http jivp.eurasipjournals.eom content 2011 1 11 D EURASIP Journal on Image and Video Processing a SpringerOpen Journal RESEARCH Open Access Fast correlation technique for glacier flow monitoring by digital camera and space-borne SAR images 1 1.2 3 1.4 1 2 Flavien Vernier Renaud Fallourd Jean Michel Friedt Yajing Yan Emmanuel Trouvé Jean-Marie Nicolas and Luc Moreau5 Abstract Most of the image processing techniques have been first proposed and developed on small size images and progressively applied to larger and larger data sets resulting from new sensors and application requirements. In geosciences digital cameras and remote sensing images can be used to monitor glaciers and to measure their surface velocity by different techniques. However the image size and the number of acquisitions to be processed to analyze time series become a critical issue to derive displacement fields by the conventional correlation technique. In this paper a mathematical optimization of the classical normalized cross-correlation and its implementation are described to overcome the computation time and window size limitations. The proposed implementation is performed with a specific memory management to avoid most of the temporary result recomputations. The performances of the software resulting from this optimization are assessed by computing the correlation between optical images of a serac fall and between Synthetic Aperture Radar SAR images of Alpine glaciers. The optical images are acquired by a digital camera installed near the Argentière glacier Chamonix France and the SAR images are acquired by the high resolution TerraSAR-X satellite over the Mont-Blanc area. The results illustrate the potential of this implementation to derive dense displacement fields with a computational time compatible with the camera images acquired every 2 h and with the size of the TerraSAR-X scenes covering 30 X 50 km2. 1 .