Quantification of Alpine Grassland Fractional Vegetation Cover Retrieval Uncertainty Based on Multiscale Remote Sensing Data
Quantification of Alpine Grassland Fractional Vegetation Cover Retrieval Uncertainty Based on Multiscale Remote Sensing Data
复制标题
基于多尺度遥感数据的高寒草原植被覆盖率反演不确定性量化
DOI：
10.1109/lgrs.2021.3109725
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发表时间：
2022
影响因子：
4.8
通讯作者：
Xiaowen Han
中科院分区：
文献类型：
--
作者：
Xingchen Lin;Jianjun Chen;Peiqing Lou;Shuhua Yi;Guoqing Zhou;Haotian You;Xiaowen Han
高空间分辨率卫星遥感图像的植被覆盖率(FVC)反演结果通常被提升为低空间分辨率卫星遥感图像的训练和验证数据(FVCUIH)。然而，很少有研究关注空间尺度转换对FVC检索精度评估的影响。在这项研究中，我们首先研究了空间尺度转换对基于三个尺度(Sentinel-2 MSI、Landsat-8 OLI和MODIS)的无人机FVC的FVC反演精度的影响。在此基础上，提出了NDVI阈值方法，进一步分析了下垫面非均质性带来的不确定性。结果表明，在空间尺度转换过程中使用FVCUIH作为训练和验证数据，会导致FVC精度被高估，其对FVC提取的影响不容忽视。此外，测量站点下垫面非均质性的不确定性增加了FVC反演的不确定性，而这些结果可以通过检测下垫面非均质性来优化。我们的结果表明，空间尺度转换和下垫面非均质性都会导致FVC反演的不准确，而后者可以通过检测下垫面的非均质性来优化。本研究为提高基于单尺度FVC测量数据的多尺度FVC检索精度提供了参考。
Fractional vegetation cover (FVC) retrieval results of high spatial resolution satellite remote sensing images are usually upscaled as training and validation data (FVCUIH) for low spatial resolution satellite remote sensing images. However, few studies have focused on the impact of the spatial scale conversion on the evaluation of FVC retrieval accuracy. In this study, we first investigated the influence of spatial scale conversion on FVC retrieval accuracy based on FVC measured by unmanned aerial vehicle (FVCUAV) at three scales (Sentinel-2 MSI, Landsat-8 OLI, and MODIS). Then, the NDVI threshold method is proposed to further analyze the uncertainty caused by the underlying surface heterogeneity. The results showed that the use of FVCUIH as training and validation data in the process of spatial scale conversion led to overestimation of FVC accuracy, and its influence on FVC retrieval cannot be ignored. In addition, the uncertainty of the underlying surface heterogeneity at the measured sites increased the uncertainty of the FVC retrieval, while these results could be optimized by detecting the underlying surface heterogeneity. Our results suggested that both spatial scale conversion and underlying surface heterogeneity would cause the inaccurate FVC retrieval, while the latter could be optimized by detecting the underlying surface heterogeneity. This study provided a reference for the improvement of multiscale FVC retrieval accuracy based on single-scale FVC-measured data.