## The equation of SS aerosol reflectance to MS aerosol reflectance

liugers11
Posts: 18
Joined: Fri Mar 01, 2013 2:08 pm America/New_York

### The equation of SS aerosol reflectance to MS aerosol reflectance

Hi?
We want to convert the OLCI SS aerosol reflectance to MS aerosol reflectance using the equation in aerosol.c as follows.
lnrhoas = log(rhoas[iw]*aeroob(sensorID,iw,cf,wv))
rhoa[iw] = exp(a + b*lnrhoas + c*lnrhoas*lnrhoas);
I have a few questions.
(1)  for the OLCI images, can I set aeroob(sensorID,iw,cf,wv) =1?
(2)  If aeroob(sensorID,iw,cf,wv)=1, I use aerosol_olci_r80f00v01.hdf to test this process. When solz=27.5, senz=7.66769, phi=15, and wavelength=400 nm, the values of acost?bcost and ccost are-0.838569,0.850478, and -0.0152793. Do the values of acost, bcost, and ccost represent a,b and c in the above equation?
(3)  If it is true. When rhoas_400 =0.01, the calculation result of rhoa_400 is 0.006225. The MS aerosol reflectance is lower than SS serosol reflectance. Where am I wrong?
Thank you very much.

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OB.DAAC - SeanBailey
User Services Posts: 1220
Joined: Wed Sep 18, 2019 6:15 pm America/New_York

### The equation of SS aerosol reflectance to MS aerosol reflectance

> (1)  for the OLCI images, can I set aeroob(sensorID,iw,cf,wv) =1?

You could, or you could implement the correction from aerosol.c using the coefficients in \$OCDATAROOT/olci/msl12_sensor_info.dat

> (2)  If aeroob(sensorID,iw,cf,wv)=1, I use aerosol_olci_r80f00v01.hdf to test this process. When solz=27.5, senz=7.66769, phi=15, and wavelength=400 nm, the values of acost?bcost and ccost are-0.838569,0.850478, and -0.0152793. Do the values of acost, bcost, and ccost represent a,b and c in the above equation?

Yes, acost, bcost and ccost are the coeffiicients for the MS->SS quadratic equation

> (3)  If it is true. When rhoas_400 =0.01, the calculation result of rhoa_400 is 0.006225. The MS aerosol reflectance is lower than SS serosol reflectance. Where am I wrong?

Sean

liugers11
Posts: 18
Joined: Fri Mar 01, 2013 2:08 pm America/New_York

Hi, Sean