Chl data Geo tiff conversion

[marpet]

The results can be improved by providing more accurate values for e.g., salinity and air pressure.
As discussed here:

Which web does the SNAP get the auxiliary data for atmospheric correction？

The influence on the result of the four parameters is quite different. So, the need to provide the values is different. Following some comments on the parameters. Ozone: The sensitivity to ozone is quite significant. The resulting water leaving reflectance spectra varies particularly in the blue. The good news is that there are good observations from satellite, and also model predications are as good as needed for AC over ocean. For MERIS and OLCI, ozone is taken from ECMWF data contained in t…

Also finding better conversion factors for chl can improve the results. This is discussed here:

C2RCC Conversion Coefficient for Chl-a and TSM

Yes, it is more like changing the values by good guesses than following some exact procedure. Following some general advice: The native output of the neural nets are inherent optical properties (absorption and scattering) of the water. Their magnitude relates to mass concentrations of water constituents, like Chl-a pigment or total suspended matter. The conversion of IOPs into mass concentration depends on the specific properties of the water and may depend on local conditions. How the default…

As simple start for masking the clouds you can use the quality_flags_bright to the valid-pixel expression.
Change it from
!quality_flags.invalid && (!quality_flags.land || quality_flags.fresh_inland_water)
to
!quality_flags.invalid && (!quality_flags.land || quality_flags.fresh_inland_water) && !quality_flags_bright

For even better results you can use Idepix (additional plugin installable vie the plugin manager). You run idepix first merge the resulting mask into the L1 product and use the created mask in the valid-pixel expression.

In addition, on the C2RCC Community you can find the limits the neural net can provide for apig and btot. If the constituents of your water are outside of this range, you won’t get good results with C2RCC. There are also the limits provided for chl and tsm using the standard conversion.