[2] There are two different approaches to determine the concentration of optically active water components by the study of spectra, distributions of light energy over a range of wavelengths or colors.
[1][2] Accurate calibration of the relationships and/or models used is an important condition for successful inversion on water remote sensing techniques and the determination of concentration of water quality parameters from observed spectral remote sensing data.
[3] The gradual development of understanding of the transparency of natural waters and of the reason of their clarity variability and coloration has been sketched from the times of Henry Hudson (1600) to those of Chandrasekhara Raman (1930).
[4] However, the development of water remote sensing techniques (by the use of satellite imaging, aircraft or close range optical devices) didn't start until the early 1970s.
This physically based model was successfully applied in order to estimate suspended sediment concentrations.
A very high concentration of green pigments like chlorophyll might indicate the presence of an algal bloom, for example, due to eutrophication processes.