传统的光学遥感变化监测方法,由于需要额外的数据支持,无法消除观测系统和地形等的误差影响,且相关分析存在偏差,精度较低,操作困难,因而难以广泛应用于地表形变监测等方面。采用光学影像配准和相关性分析(Co-registration of Optically...传统的光学遥感变化监测方法,由于需要额外的数据支持,无法消除观测系统和地形等的误差影响,且相关分析存在偏差,精度较低,操作困难,因而难以广泛应用于地表形变监测等方面。采用光学影像配准和相关性分析(Co-registration of Optically Sensed Images and Correlation,COSI-Corr)方法,无需地面控制点,可以实现影像的高精度配准和地表位移测量,且由于其广泛的适用性与较高的精度,已成为地表变形研究领域的一个热点,引起了研究者的广泛关注。本文首先探讨了COSI-Corr的技术原理和分析流程,并对该方法在大震同震位移测量、冰川变化监测、滑坡活动监测等方面的实际应用及其优点进行了详细介绍。最后讨论了该方法应用中的关键问题和发展前景。研究表明:光学影像配准和相关性分析方法(COSI-Corr)操作简单、效率高、分辨率高达1/10像素,可用的遥感影像数据多,并且可以应用于LiDAR差分研究中,与InSAR具有互补性,该方法可以广泛地应用在地表形变监测当中。展开更多
沙丘移动与形态监测是风沙地貌研究的重要内容,传统的测量方法对大范围的风沙地貌进行动态监测存在很大的困难。光学影像配准与关联(Co-registration of Optically Sensed Images and Correlation,COSI-Corr)技术的出现为区域风沙地貌...沙丘移动与形态监测是风沙地貌研究的重要内容,传统的测量方法对大范围的风沙地貌进行动态监测存在很大的困难。光学影像配准与关联(Co-registration of Optically Sensed Images and Correlation,COSI-Corr)技术的出现为区域风沙地貌的动态演化与监测研究提供了良好契机。讨论了COSI-Corr技术在沙丘移动和形态监测中的优势和存在的主要问题,通过无人机野外地面实测结果检验了COSI-Corr的测量精度。结果表明:沙丘背风坡底缘COSI-Corr测量精度最高,月测量误差0.01~0.53 m,达到影像分辨率的1/30像元;在沙丘背风坡底缘,COSI-Corr测量精度与沙丘底面积呈线性关系,底面积越大,COSI-Corr测量误差越大;个别沙丘脊线部位出现极大异常点,与沙丘脊线部位的光噪影响有关。COSI-Corr技术在风沙地貌监测中尚属起步阶段,一些具体的问题还需要我们在实践中不断的去检验和改进,但它确实极大提高了野外风沙地貌动态监测的效率,为研究大尺度范围内风沙地貌的时空动态演化过程提供了可能,在未来的风沙地貌研究中将具有广阔的应用前景。展开更多
Karakoram Himalaya(KH) has continental climatic conditions and possesses largest concentration of glaciers outside the polar regions. The melt water from these glaciers is a major contributor to the Indus river. In th...Karakoram Himalaya(KH) has continental climatic conditions and possesses largest concentration of glaciers outside the polar regions. The melt water from these glaciers is a major contributor to the Indus river. In this study, various methods have been used to estimate the ice volume in the Karakoram Range of glaciers such as Coregistration of Optically Sensed Images and Correlation(COSI-Corr) method and Area-Volume relations. Landsat 8 satellite data has been used to generate the ice displacement, velocity and thickness map. Our study for 558 Karakoram glaciers revealed that the average ice thickness in Karakoram is 90 m. Ground Penetrating Radar(GPR) survey has been conducted in one of the KH glacier i.e. Saser La glacier and the collected GPR data is used for the validation of satellite derived thickness map. GPR measured glacier thickness values are found comparable with satellite estimated values with RMSE of 4.3 m. The total ice volume of the Karakoram glaciers is estimated to be 1607±19 km3(1473±17 Gt), which is equivalent to 1473±17 km3 of water equivalent. Present study also covers the analysis of glacier surface displacement, velocity and ice thickness values with reference to glacier mean slope.展开更多
文摘传统的光学遥感变化监测方法,由于需要额外的数据支持,无法消除观测系统和地形等的误差影响,且相关分析存在偏差,精度较低,操作困难,因而难以广泛应用于地表形变监测等方面。采用光学影像配准和相关性分析(Co-registration of Optically Sensed Images and Correlation,COSI-Corr)方法,无需地面控制点,可以实现影像的高精度配准和地表位移测量,且由于其广泛的适用性与较高的精度,已成为地表变形研究领域的一个热点,引起了研究者的广泛关注。本文首先探讨了COSI-Corr的技术原理和分析流程,并对该方法在大震同震位移测量、冰川变化监测、滑坡活动监测等方面的实际应用及其优点进行了详细介绍。最后讨论了该方法应用中的关键问题和发展前景。研究表明:光学影像配准和相关性分析方法(COSI-Corr)操作简单、效率高、分辨率高达1/10像素,可用的遥感影像数据多,并且可以应用于LiDAR差分研究中,与InSAR具有互补性,该方法可以广泛地应用在地表形变监测当中。
文摘沙丘移动与形态监测是风沙地貌研究的重要内容,传统的测量方法对大范围的风沙地貌进行动态监测存在很大的困难。光学影像配准与关联(Co-registration of Optically Sensed Images and Correlation,COSI-Corr)技术的出现为区域风沙地貌的动态演化与监测研究提供了良好契机。讨论了COSI-Corr技术在沙丘移动和形态监测中的优势和存在的主要问题,通过无人机野外地面实测结果检验了COSI-Corr的测量精度。结果表明:沙丘背风坡底缘COSI-Corr测量精度最高,月测量误差0.01~0.53 m,达到影像分辨率的1/30像元;在沙丘背风坡底缘,COSI-Corr测量精度与沙丘底面积呈线性关系,底面积越大,COSI-Corr测量误差越大;个别沙丘脊线部位出现极大异常点,与沙丘脊线部位的光噪影响有关。COSI-Corr技术在风沙地貌监测中尚属起步阶段,一些具体的问题还需要我们在实践中不断的去检验和改进,但它确实极大提高了野外风沙地貌动态监测的效率,为研究大尺度范围内风沙地貌的时空动态演化过程提供了可能,在未来的风沙地貌研究中将具有广阔的应用前景。
基金Department of Science and Technology (DST), New Delhi for financial support to project no. SB/DGH-102/2015
文摘Karakoram Himalaya(KH) has continental climatic conditions and possesses largest concentration of glaciers outside the polar regions. The melt water from these glaciers is a major contributor to the Indus river. In this study, various methods have been used to estimate the ice volume in the Karakoram Range of glaciers such as Coregistration of Optically Sensed Images and Correlation(COSI-Corr) method and Area-Volume relations. Landsat 8 satellite data has been used to generate the ice displacement, velocity and thickness map. Our study for 558 Karakoram glaciers revealed that the average ice thickness in Karakoram is 90 m. Ground Penetrating Radar(GPR) survey has been conducted in one of the KH glacier i.e. Saser La glacier and the collected GPR data is used for the validation of satellite derived thickness map. GPR measured glacier thickness values are found comparable with satellite estimated values with RMSE of 4.3 m. The total ice volume of the Karakoram glaciers is estimated to be 1607±19 km3(1473±17 Gt), which is equivalent to 1473±17 km3 of water equivalent. Present study also covers the analysis of glacier surface displacement, velocity and ice thickness values with reference to glacier mean slope.
