Yanli Zhang , Pan Zhao , Xin Li , Bisheng Yang , Jun Zhao , Jiazheng Hu , Qi Wei , Kegong Li , Mingliang He
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引用次数: 0
Abstract
Land elevation data are indispensable for topographic mapping and geological disaster monitoring. However, the existing ICESat-2/ATL08 (V04) product has a coarse resolution (≥100 m) and is characterized by high uncertainty in mountainous areas; thus, it cannot be used to describe terrain relief characteristics accurately. In this study, a new method for extracting terrain surface elevation is proposed, which uses a local statistical denoising algorithm for mountainous areas (LSDAMA) based on the raw georeferenced photon product ICESat-2/ATL03. Coarse denoising is based on performing histogram thresholding, and refined denoising is based on local slope fitting; the process of performing coarse denoising twice and then refined denoising not only improves the removal effect for noise photons but also increases the signal photon retention rate in mountainous areas. Additionally, the estimation accuracy of the terrain surface elevation can be improved by setting rectangular dynamic windows along the fitted slope direction. Using the Babao River Basin in the Qilian Mountains as the research area, a total of 137 validation points from 777 GPS CORS in 40 quadrats and UAV LiDAR measurements were used to verify the accuracy. The results showed that the terrain surface elevations estimated by the LSDAMA are more accurate than those estimated by the ATL08 official products, especially in mountainous areas with slopes greater than 20°. The root mean square error (RMSE) of the LSDAMA decreased from 2.72 m for the ATL08 product to 0.60 m, and the mean deviation (MBE) decreased from −1.27 to 0.04 m. Additionally, the LSDAMA greatly improved the signal photon retention rate and reduced the interval between adjacent elevation points from 100 m for the ATL08 product to 2–7 m; this reduced interval can be used to describe the terrain fluctuation characteristics in detail, thus providing reliable basic data for monitoring terrain surface elevation changes in mountainous areas.
期刊介绍:
Remote Sensing of Environment (RSE) serves the Earth observation community by disseminating results on the theory, science, applications, and technology that contribute to advancing the field of remote sensing. With a thoroughly interdisciplinary approach, RSE encompasses terrestrial, oceanic, and atmospheric sensing.
The journal emphasizes biophysical and quantitative approaches to remote sensing at local to global scales, covering a diverse range of applications and techniques.
RSE serves as a vital platform for the exchange of knowledge and advancements in the dynamic field of remote sensing.