ABSTRACT

There are a wide range of satellite sensors used for water quality measures with various spatial resolutions. Here, we focus on spatial resolution because some estuaries are smaller than the satellite nadir pixel width, and multiple pixels within an estuary are required for quality assurance . We used the United States Environmental Protection Agency’s (US EPA) Estuarine Data Mapper polygon set to determine the spatial resolution required to reliably image every estuary and sub-estuary in the continental US. Kilometre resolution ocean colour sensors resolve 25% of estuaries and 36% of sub-estuaries with a 3 × 3-pixel grid. The 300 m Ocean and Land Colour Instrument (OLCI) on Sentinel-3 resolves 53% of continental US estuaries with a 3 × 3-pixel grid, and 85% of sub-estuaries. Currently orbiting 30 m resolution land imaging satellites are sufficient to resolve all US sub-estuaries and all estuaries in the Atlantic, 89% in the Gulf of Mexico, and 54% in the Pacific with a 3 × 3-pixel grid. However, 45% of Pacific estuaries cannot be resolved at 30 m resolution, because they have narrow riverine morphology. Our results indicate that a resolution of ≤15 m will be necessary to resolve these narrow riverine estuaries, which is only currently available with commercial satellites.

摘要

有各种各样的卫星传感器用于各种空间分辨率的水质测量。这里，我们关注于空间分辨率，因为某些河口小于卫星最低点像素宽度，并且河口内需要多个像素以确保质量。我们使用了美国环境保护局（US EPA）的“河口数据映射器”多边形集来确定对美国大陆上的每个河口和子河口进行可靠成像所需的空间分辨率。公里分辨率的海洋颜色传感器使用3×3像素的网格可分辨25％​​的河口和36％的子河口。Sentinel-3上的300 m海洋和陆地颜色仪器（OLCI）可分辨3％3像素网格的53％的美国大陆河口和85％的子河口。目前运行的30 m分辨率陆地成像卫星足以分辨3×3像素网格的所有美国子河口和大西洋，墨西哥湾的89％和太平洋的54％的所有河口。但是，由于30％的太平洋河口具有狭窄的河流形态，因此无法分辨30％的太平洋河口。我们的结果表明，解析这些狭窄的河口河口，需要≤15 m的分辨率，而目前只有商业卫星才能使用。