Abstract
The dominant wavelength and hue angle can be used to quantify the color of lake water. Understanding the water color is important because the color relates to the water quality and its related public perceptions. In this paper, we compared the accuracy levels of two methods in calculating dominant wavelength and hue angle values using simulated satellite data calculated from in situ reflectance hyperspectra for 325 lakes and rivers in Minnesota and Wisconsin. The methods developed by van der Woerd and Wernand in 2015 and Wang et al. in 2015 were applied to simulated sensor data from the Sentinel-2, Sentinel-3, and Landsat 8 satellites. Both methods performed comparably when a correction algorithm could be applied, but the correction method did not work well for the Wang method at hue angles < 75°, equivalent to levels of colored dissolved organic matter (CDOM, a440) > ~2 m−1 or chlorophyll > ~10 mg m−3. The Sentinel-3 spectral bands produced the most accurate results for the van der Woerd and Wernand method, while the Landsat 8 sensor produced the most accurate values for the Wang method. The distinct differences in the shapes of the reflectance hyperspectra were related to the dominant optical water quality constituents in the water bodies, and relationships were found between the dominant wavelength and four water quality parameters, namely the Secchi depth, CDOM, chlorophyll, and Forel–Ule color index.
Original language | English (US) |
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Article number | 1071 |
Journal | Sensors |
Volume | 23 |
Issue number | 3 |
DOIs | |
State | Published - Feb 2023 |
Bibliographical note
Funding Information:For the Minnesota hyperspectral data, we gratefully acknowledge support from the U.S. National Science Foundation, the Minnesota Environmental and Natural Resources Trust fund, as recommended by the Legislative-Citizen Commission on Minnesota Resources and Univ. of Minnesota’s Office of the VP for Research and Retirees Association, U-Spatial Program, Sea Grant Program, and Agricultural Experiment Station. We thank the Lake Superior National Estuarine Research Reserve and the reserve manager Shon Schooler for their sampling assistance on the St. Louis River Estuary. We greatly appreciate the assistance of Bryan Leavitt and Rick Perk, CALMIT, University of Nebraska, for the spectroradiometer system setup and their helpful advice in operating the system and interpreting the data. For access to the Wisconsin hyperspectral data, we gratefully acknowledge Daniela Gurlin and the Wisconsin Department of Natural Resources. For the original concept of the paper and assistance with data collection and analysis while he was at the University of Minnesota and for the pre-submittal review of the manuscript, we gratefully acknowledge Benjamin Page, USGS Earth Resources Observation and Science (EROS) Center. We are thankful for the code that Moritz Lehmann provided, which was useful for converting hue angles to dominant wavelengths and producing plots of the CIE color space. Professor Vaughan Voller provided useful comments on the honors thesis by M.B. that served as the basis for the initial draft of the manuscript.
Publisher Copyright:
© 2023 by the authors.
Keywords
- Forel–Ule index
- Landsat 8
- Sentinel-2
- Sentinel-3
- chlorophyll
- colored dissolved organic matter (CDOM)
- dominant wavelength
- hue angle
- reflectance spectra
- water color
PubMed: MeSH publication types
- Journal Article