How to calculate chlorophyll a concentration from sentinel 2 images


#1

Hello folks,
I’m searching a method to obtain chl-a concentration (mg/L) from Sentinel 2 images.
I need a good spatial resolution (<100m) so I cannot use the S3 data.
I read that the measure should be based on the reflectance of two or more bands.
I’d prefer to use SNAP software.
Linked to that, I’m looking to replicate this type of algal bloom visualization. Can anyone tell me the STEP bands values to set to obtain it?
Thank you very much


#2

You can use C2RCC processor.
Please have a look here:


#3

Thank you very much for your immediate reply, this answers to the first question, for the visualization instead?


#4

Regarding the visualisation, I don’t know. But you can colourise the result as you like.
Probably it will not look like very similar on the first try.
I have no idea how the image was generated which you referenced.


#5

I’d recommend installing QGIS and trying to apply different colour gradients to your raster output!

https://www.qgistutorials.com/en/docs/raster_styling_and_analysis.html


#6

Thank you very much guys!


#7

By the way, when the geotiff is exported, for example in qgis, which layer has the chl-a concentration? once exported the layers stacked into the geotiff have lost their description


#8

Is there a way you can only export the relevant layer out as a geotiff from SNAP?


#9

Why don’t you just open the img file of the BEAM DIMAP format in QGIS?
Geotiff can’t story metadata.


#10

Right-click > Spatial subset from view > band subset