C2RCC Conversion Coefficient for Chl-a and TSM

[torres6]

Good Day.

How can I compute for the appropriate TSM factor bpart/bwit and Chl exponent/factor in the C2RCC parameters? Do I need to obtain first in-situ TSM and Chl values in order to compute for them?

[marpet]

Hi,

similar question was already discussed here:

Retriving chlorophyll and turbidity from sentinel data

The quality can be different for different regions. You should have insitu data to compare the results with real data. As @ABraun said, you.can provide salinity and temperature to improve the results. Also the factors and exponen for tsm and chl computation can be adapted to match your region. [image] You have to find out which values are best. When opening the properties for the band you can edit the values. [image] Once you found good values you can provide them to the processing.

The provided values give good general results with the neural net. But for special region they might need to be adapted. For doing this adaptation you need in-situ data.

[Ceren]

Thanks for explanation. I also need to know what is the chlorophyll exponent and chlorophyll factor. As I understand factor is in-situ value ? could you please answer me.

[marpet]

I think this post can answer your question:

C2RCC_more_information

Hi Ximena! These factors are the conversion from IOPs to concentrations on the bases of empirical relationships. For OLCI you have: chl = 21.0 ∗ (a_pig443)^1.04 tsm= 1.06 * (bp + bw)^0.942 The factors and exponents were derived with NOMAD data mainly (and some coastal data). If you have your own data measured in situ, you could try to derive this relationship by yourself and change the factors conveniently to your study area. That should improved the conversion to fit ranges closer to your …

[Ceren]

your explanation is very clear, thank you.