Firstly, I want to say thank you to prepare document about convert raw sequoia images to reflectance. Thanks to your document I start to understand how sequoia works. I am so grateful to you.
I don’t understand one part of this document. When we calculate of sunshine irradiance, we use this formula.
Iss’= k1 x (V/(g*t))= k1 x Iss
-We use Iss instead of Iss’
-t is exposure time which exist in the exif data of image.
-v is CHO count.
-g is relative gain factor.
Relative gain factor not clear for me. Because we have 4 gain index and which one is suitable for us. Which one we should rate. You say in your documents, sequoia use gain1 so CHO value is clear (330 in your example). But what is the relative gain? gainO/gain1 (11/330) or gain1/gain2 (330/3990) or gain2/gain1(3990/330)