Dear Quinten,
I am a new user of Acolite, I read the manual, but still I have some questions that I hope you can clarify for me. I apply Acolite in an area of my country (Peru), so is it correct my interpretation about the output file?
Rhot_*, I think in this image the pixels do not have any atmospheric correction, because in my output image the water spectral profile is high in short waveband (400-600 nm), and the value are from 0 to 0.4 approx, so they are in reflectance units because the range must be 0-1.
Rhos_*, in this case, my question is the pixels have any atmospheric correction? Because my water pixels has low values in short waveband, and the value are from 0 – 0.4 also.
Rhow_*, in this output, as I read just the water pixels are converted to reflectance, but with more complex atmospheric correction algorithm, so to speak… and it just represent the water leaving radiance, that´s the reason my range and value are so small 0 – 0.09., very far from 1.
Thank for any help
Erick
Differences between some Acolite outputs
Re: Differences between some Acolite outputs
Hi Erick
Indeed the rhot variables represent the top-of-atmosphere reflectance, i.e. the ratio of radiance measured by the sensor to the (modeled) extraterrestrial solar irradiance, and a factor pi over the cosine of the sun zenith angle.
The rhos is the surface level reflectance, i.e. after atmospheric correction. The rhow is the water leaving radiance reflectance, which in ACOLITE outputs is currently the same as rhos with additional masking applied. If any water specific corrections are applied, i.e. for interface (sky/sun glint) reflectance, are also applied at the rhos level.
Some more details about the products and masking can be found here.
I hope this is clear!
Quinten
Indeed the rhot variables represent the top-of-atmosphere reflectance, i.e. the ratio of radiance measured by the sensor to the (modeled) extraterrestrial solar irradiance, and a factor pi over the cosine of the sun zenith angle.
The rhos is the surface level reflectance, i.e. after atmospheric correction. The rhow is the water leaving radiance reflectance, which in ACOLITE outputs is currently the same as rhos with additional masking applied. If any water specific corrections are applied, i.e. for interface (sky/sun glint) reflectance, are also applied at the rhos level.
Some more details about the products and masking can be found here.
I hope this is clear!
Quinten