EO Browser and Cyanobacteria
Introduction
A timelapse video of amount of cyanobacteria in Baltic Sea using ESA's EO Browser.
Theory
Satellites
https://ntrs.nasa.gov/citations/20200001476
Medium Resolution Imaging Spectrometer (MERIS) sensor in the solar spectral range (390 to 1040 nm in 15 spectral bands) on the Envisat satellite (2002 to 2012).
The CyAN project.
Cyanobacteria index https://catalog.data.gov/dataset/cyanobacteria-index-meris "MERIS imagery was used to identify long-wavelength spectral bands (from red through near-infrared portion of the spectrum) to locate algal blooms within freshwaters and estuaries of the continental United States."
Center wavelength of red band ~630-670 nm.
https://www.nature.com/articles/s41598-019-54453-y
- "The new method can be applied to Sentinel-3 Ocean Land Color Imager (OLCI) data"
- " Among cyanoHAB assessment studies using remote sensing methods, a few have looked at several lakes at a time14,15,16, but a majority of the efforts have focused on one body of water such as the Baltic Sea17, Lake Balaton, Hungary18, the Caspian Sea19, Lake Taihu, China20,21, and Lake Erie11,12,22."
https://bg.copernicus.org/articles/11/3619/2014/ https://bg.copernicus.org/articles/11/3619/2014/bg-11-3619-2014.pdf
- Detailed paper about techniques.
- "The satellite algorithm is based on remote sensing reflectance of the water in the red band, a measure of turbidity. "
- "The fraction with cyanobacteria accumulations was calculated as the ratio of the number of detected accumulations to the number of cloud-free sea-surface views per pixel during the season (July–August). "
- "For detecting cyanobacteria we used only satellite passes near local noon (10:00–14:00 local time), as atmospheric scattering and absorption mask the relatively weak signal from the water surface at low sun elevation"
- 11th July 2005. Great image.
