How can i obtain the MODIS Rayleigh correction reflectance from SeaDAS L2gen?

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mary0916
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How can i obtain the MODIS Rayleigh correction reflectance from SeaDAS L2gen?

by mary0916 » Tue Jun 04, 2024 5:14 am America/New_York

How can i obtain the MODIS Rayleigh correction reflectance from SeaDAS L2gen? I know that rhos can be selected from L2gen, but does the final result directly represent Rayleigh-corrected reflectance? What additional treatment is needed to obtain strict Rayleigh-corrected reflectance?

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OB.DAAC - SeanBailey
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Re: How can i obtain the MODIS Rayleigh correction reflectance from SeaDAS L2gen?

by OB.DAAC - SeanBailey » Tue Jun 04, 2024 4:20 pm America/New_York

The rhos product is Rayleigh and gaseous absorption corrected reflectance. If you want a product that only removes the Rayleigh radiance component, you'll have to output Lt and Lr (and likely the Rayleigh transmittances, t_sen and t_sol) and do the math.

The rhos that l2gen ouputs is:

Code: Select all

rhos = pi / Fo / mu0 * (Lt / tg_sol/ tg_sen - Lr) / t_sol / t_sen / t_o2 / t_h2o
where:
Lt = Top-of-atmosphere radiance
Lr = Rayliegh radiance
Fo = extraterrestrial irradiance
mu0 = cosine of solar zenith angle
tg_sol, tg_sol, t_o2, t_h2o = Transmittance due to gaseous absorption (ozone, oxygen, water vapor, etc.) for
solar path (sol) and sensor view path (sen)
t_sen, t_sol = Rayleigh-aerosol diffuse transmittance for solar path (sol) and
sensor view path (sen)

Sean

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