State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China.
The Second Design and Research Institute of Water Conservancy Hydropower of Hebei Province, Shijiazhuang 50021, China.
Sensors (Basel). 2019 Oct 9;19(20):4360. doi: 10.3390/s19204360.
Measurements of the above-water spectrum and concerned water color parameters (WCPs) are crucial for research and applications in water environment remote sensing. Due to the lack of system integration and automatization, conventional methods are labor-intensive, time-consuming, and prone to subjective influences. To obtain a highly accurate and long-term consistent spectrum and concurrent WCPs (Chl-a (chlorophyll-a), turbidity, and CDOM (Colored Dissolved Organic Matter)) data with a relatively low cost, an Automatic Stationary Water Color Parameters Observation System (AFWCPOS) was developed. Controlled by an automatic platform, the spectral and WCPs data were collected by TriOS RAMSES hyperspectral spectroradiometers and WETLabs ECO (Environmental Characterization Optics) fluorometers following the measurement protocol. Experiment and initial validations of AFWCPOS were carried out in Poyang Lake, the largest freshwater lake in China, from 20 to 28 July 2013. Results proved that the spectral data from AFWCPOS were highly consistent with the commonly used portable SVC (Spectra Vista Corporation) HR-1024 field spectroradiometer, with the coefficient of determination () of 0.96, unbiased percent difference (UPD) of 0.14, and mean relative difference (MRD) of 0.078. With advantages of continuous and high degrees of automation monitoring, the AFWCPOS has great potential in capture diurnal and inter-diurnal variations in the test site of Poyang Lake, as well as another high-dynamic shallow coastal and inland waters, which will benefit routine water quality monitoring with high quality and high-frequency time-series observations. In addition, a successful case based on Landsat 8 OLI (Operational Land Imager) image and in-situ data collected by AFWCPOS showed it's potential in remote sensing applications. The spatial distribution of Chl-a, turbidity, and CDOM were mapped, which were explainable and similar to previous researches. These results showed our system was able to obtain reliable and valuable data for water environment monitoring.
水上光谱和相关水质参数（WCPs）的测量对于水环境保护遥感的研究和应用至关重要。由于缺乏系统集成和自动化，传统方法劳动强度大、耗时且容易受到主观影响。为了以相对较低的成本获得高度准确和长期一致的光谱和并发 WCPs（Chl-a（叶绿素-a）、浊度和 CDOM（有色溶解有机物质））数据，开发了自动固定式水色参数观测系统（AFWCPOS）。该系统由自动平台控制，根据测量协议，使用 TriOS RAMSES 高光谱分光辐射计和 WETLabs ECO（环境特征光学）荧光计收集光谱和 WCPs 数据。2013 年 7 月 20 日至 28 日，在中国最大的淡水湖鄱阳湖进行了 AFWCPOS 的实验和初步验证。结果证明，AFWCPOS 的光谱数据与常用的便携式 SVC（Spectra Vista Corporation）HR-1024 野外分光辐射计高度一致，决定系数（）为 0.96，无偏百分比差异（UPD）为 0.14，平均相对差异（MRD）为 0.078。由于具有连续和高度自动化监测的优势，AFWCPOS 具有在鄱阳湖试验场捕获昼夜和日内变化的巨大潜力，以及另一个高动态浅沿海和内陆水域，这将有利于常规水质监测，提供高质量和高频时间序列观测。此外，基于 Landsat 8 OLI（操作陆地成像仪）图像和 AFWCPOS 收集的现场数据的成功案例表明了其在遥感应用中的潜力。绘制了 Chl-a、浊度和 CDOM 的空间分布，这些分布是可解释的，与以前的研究相似。这些结果表明，我们的系统能够为水环境保护监测获得可靠和有价值的数据。
