reducing the number of masked pixels

[cio]

Hi Quinten,

Wondering if you have an idea of the best masking threshold to set for an image from the Bahamas area - to get more valid pixels.

I can show you the Sentinel-2 image, if you want.

Regards.

[quinten]

Probably the bulk of pixels are masked due to the SWIR threshold applied or by negatives retrieved after the atmospheric correction. You can increase the SWIR threshold and disable the masking of negatives in the Advanced settings menu (or by editing your settings file).

Since you are working with Bahamas imagery, I believe this masking will be the result of sun glint, and therefore do not recommend changing these settings. No glint correction is implemented in ACOLITE and the outputs would be wrong. It would be helpful to have the scenes you are working on.

[cio]

Thanks Quinten,

See the image below and result from red-nir correction.

bahams_red_swir_band_comb.PNG (236.6 KiB) Viewed 77205 times

bahamas.PNG (432.8 KiB) Viewed 77205 times

[cio]

Hi again Quinten,

In addition to the above, I also have extremely low values in the green channel. The area has low chlorophyll which suggests Rrs should be around 0.002 (I guess), but I have values way lower than half of that (with 3 zero digits after decimal point). Any pointer?

Thanks!