Illumination state filtering too aggresive?

[vudongpham]

Hi David,
Take this scene as example X0069_Y0037/20241011_LEVEL2_LND08_BOA (sorry I forget the original Landsat id):

a) Here is the cso masking (including poor illumination) using following parameters

cso_list = {
    'Valid data' : ['0'],
    'Cloud state' : ['00'],
    'Cloud shadow flag' : ['0'],
    'Snow flag' : ['0'],
    'Water flag': ['0', '1'],
    'Aerosol state' : ['00', '01'],
    'Subzero flag' : ['0'],
    'Saturation flag' : ['0'],
    'High sun zenith flag' : ['0'],
    'Illumination state' : ['00', '01', '10'],
    'Slope flag' : ['0', '1'],
    'Water vapor flag' : ['0', '1'],
    'Empty' : ['0']
}

b) Here is the masking (excluding poor illumination)

cso_list = {
    'Valid data' : ['0'],
    'Cloud state' : ['00'],
    'Cloud shadow flag' : ['0'],
    'Snow flag' : ['0'],
    'Water flag': ['0', '1'],
    'Aerosol state' : ['00', '01'],
    'Subzero flag' : ['0'],
    'Saturation flag' : ['0'],
    'High sun zenith flag' : ['0'],
    # Remove poor illumination
    'Illumination state' : ['00', '01'],
    'Slope flag' : ['0', '1'],
    'Water vapor flag' : ['0', '1'],
    'Empty' : ['0']
}

Is it normal to lose such a big data when masking out the poor illumination? Or do you think this is only specific for this image?

Dong