Application of Sentinel 2 MSI Images to Retrieve Suspended Particulate Matter Concentrations in Poyang Lake
Application of Sentinel 2 MSI Images to Retrieve Suspended Particulate Matter Concentrations in Poyang Lake
复制标题
应用Sentinel 2 MSI图像反演鄱阳湖悬浮颗粒物浓度
DOI：
10.3390/rs9070761
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发表时间：
2017-07-01
期刊：
影响因子：
5
通讯作者：
Zhou, Qiming
中科院分区：
文献类型：
--
作者：
Liu, Huizeng;Li, Qingquan;Zhou, Qiming
悬浮颗粒物（SPM）是内陆和近海沃茨的主要水体成分之一，而悬浮颗粒物浓度（CSPM）是描述水质的关键参数。利用Sentinel 2多光谱成像仪（MSI）遥感图像和现场光谱测量数据，建立鄱阳湖CSPM反演模型，并估算鄱阳湖CSPM值。应用68个原位高光谱测量和相对光谱响应函数来模拟Sentinel 2 MIS光谱。分别用34个样本进行校正，剩余样本用于验证CSPM反演模型。将模型应用于Sentinel 2 MSI图像，并与MODIS B1（λ = 645 nm）的CSPM值进行了比较。结果表明，Sentinel 2 MSI B4-B8 b模型达到了可接受的高拟合精度，解释了CSPM变异的81-93%。验证结果也显示了这六个模型的可靠性，估计的CSPM解释了77-93%的变异的CSPM测量的平均绝对百分比误差（MAPE）范围为36.87%至21.54%。其中，基于B7（λ = 783 nm）的模型似乎是最准确的模型。Sentinel 2 MSI-derived CSPM值在空间分布和量级上与来自MODIS的CSPM值基本一致。Sentinel 2 MSI B7的CSPM在2016年8月15日与MODIS的一致性最高，而Sentinel 2 MSI B4（λ = 665 nm）在2017年4月2日与MODIS的一致性最高。总体而言，本研究证明了Sentinel 2 MSI在鄱阳湖CSPM反演中的适用性，并且Sentinel 2 MSI B4和B7分别推荐用于低和高负载的SPM。
Suspended particulate matter (SPM) is one of the dominant water constituents in inland and coastal waters, and SPM concnetration (CSPM) is a key parameter describing water quality. This study, using in-situ spectral and CSPM measurements as well as Sentinel 2 Multispectral Imager (MSI) images, aimed to develop CSPM retrieval models and further to estimate the CSPM values of Poyang Lake, China. Sixty-eight in-situ hyperspectral measurements and relative spectral response function were applied to simulate Sentinel 2 MIS spectra. Thirty-four samples were used to calibrate and the left samples were used to validate CSPM retrieval models, respectively. The developed models were then applied to two Sentinel 2 MSI images captured in wet and dry seasons, and the derived CSPM values were compared with those derived from MODIS B1 (λ = 645 nm). Results showed that the Sentinel 2 MSI B4–B8b models achieved acceptable to high fitting accuracies, which explained 81–93% of the variation of CSPM. The validation results also showed the reliability of these six models, and the estimated CSPM explained 77–93% of the variation of measured CSPM with the mean absolute percentage error (MAPE) ranging from 36.87% to 21.54%. Among those, a model based on B7 (λ = 783 nm) appeared to be the most accurate one. The Sentinel 2 MSI-derived CSPM values were generally consistent in spatial distribution and magnitude with those derived from MODIS. The CSPM derived from Sentinel 2 MSI B7 showed the highest consistency with MODIS on 15 August 2016, while the Sentinel 2 MSI B4 (λ = 665 nm) produced the highest consistency with MODIS on 2 April 2017. Overall, this study demonstrated the applicability of Sentinel 2 MSI for CSPM retrieval in Poyang Lake, and the Sentinel 2 MSI B4 and B7 are recommended for low and high loadings of SPM, respectively.