Hi everyone! Well, I have to compare different atmospheric correction methods: Sen2Cor, iCor and C2RCC. My study area is a Estuarine Complex in the Northeast of Brazil, which is caracterized by turbid and productive waters.
With this, I’m turning a 1C level image (Top-of-atmosphere - TOA) into a 2A level corrected image (Bottom-of-atmosphere - BOA).
In order to validate each algorithm, I’m doing match-ups with in situ reflectances. It turns out that the spectral curves look alike (BOA and in situ) - not perfectly but yet almost the same spectral response to a certain band - but magnitudes of reflectance differ a lot from in situ. Here’s one of the lakes I’m using:
Here, C2RCC seems to have ignored the absorption at 665 nm and Sen2Cor seems to emphasize that absorption. Why?
See that C2RCC increased R2 but still there is great dispersion?
So my questions are:
- How can I explain those differences in spectral curves (limnological or atmospheric/orbital explanation)??
- How can I evaluate the performance (in terms of performance metrics) in a way this shape similarity could be represented? (since R2 wasn’t always good)
- How can I explain that in situ reflectances were all under 0,02 sr-1 and the others were under 0,12 sr-1 (except for C2RCC)?