Rayleigh and Aerosol LUTs

[amsuhail]

Hello,

From the previous comments from OSOAA and pyOSOAA repositories, I understand that you were able to generate Rayleigh and Aerosol LUTs for Atmospheric Correction in SeaDAS. Can you please tell about the steps involved in generating those LUTs using OSOAA..?

Regards, Suhail

[fnemina]

Dear Suhail, sorry for the delay writting back to you.

This is how I solved the generation of Rayleigh and aerosol LUTs using the OSOAA.

1. You need to disable water leaving radiance. You can do by using a big value for the yellows substance absortion (10^5) or by following the procedure of the Black ocean of the OSOAA tutotial.
2. Then you need to simulate the Rayleigh scattering for a zero aerosol optical thickness for several sun and sensor zenith angles, wind speeds and relative azimuth angles. Once you've got this you need to compute the first three Fourier transform coefficients for the azimuth directions. The forth should be zero.
3. Once you've got this you can compute the aerosol LUTs. This LUTs involve a coefficient from the multiple scattering aerosol reflectance to the single scattering one. Also the aerosol LUTs should have all the parameters necesary to compute the single scattering reflectance.

If you want we can divide this process into smaller chunks and I can help you with this. If you can make good progress with the Rayleigh LUT then it's easier to move to the Aerosol one.

Best! Fran

[Dongxianzhang]

Hi, Fran

Regarding the process of generating Rayleigh and aerosol LUTs, I have some questions that hope you could help me by providing more details. (1) The Fourier transform is applied directly to the generated LUTs (discrete table)? (2) The OSOAA can compute the single scattering aerosol reflectance and multiple scattering aerosol reflectance respectively? (3) How to account for the interaction between the molecule and aerosol?

Best wishes! Xianzhang