The Study on Water Line Extraction From Time Series of SAR Image

• Main Authors: Jing-Teng Lin, 林景騰
• Other Authors: 陳錕山
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/96671115360480377324

碩士 === 國立中央大學 === 太空科學研究所 === 95 === In this study, we proposed a waterline extraction algorithm using a time series of satellite synthetic aperture radar images over the west coast of Taiwan. First, the data preprocessing, including ortho rectification, geometric correction, radiometric correction, multi-looking, speckle filtering etc.., was devised. Then, a general idea of multi-scale, correlation analyze, edge detection, and mathematics morphology operations were applied to automatic delineate the waterlines. Delineated the waterlines which were later calibrated to the same tidal height if necessary. Verifications were conducted by GPS ground truth and ancillary data from bathymetric maps. It is found that the accuracy of the extracted waterline is about 1 pixel. Finally, preliminary observations of waterlines changes in the period of years of 1996 and 2005 were provided. Among them, Fang-Yuan Sandbar pronouncedly recess itself into a reclaimed land, while Wai-san-ting Sandbar and Hai-feng-dao Sandbar, shrinking in size, move southwardly.