The remote sensing reflectance, which is defined as the water-leaving radiance to the downwelling irradiance, is commonly used in ocean color remote sensing, but the water albedo theorectically conveys more information about waters since it is the hemispherical integration of remote sensing reflectance, why the ocean color community uses remote sensing reflectance rather than water albedo? Is there any hard nut to crack in the observation of water albedo?
I think albedo is also affected by water surface roughness like in case of calm wind and in case of high wind speed albedo can change for same downwelling irradiance but water leaving can take care of that thing, one more thing albedo can be due to water surface but water leaving reflectance is due to constituent in water (chl-a, suspended sediments etc).
correct me if i am wrong
Dear Blowman,
I am an amateur researcher in RS. I can answer your question. But the best may await you.
Answer: The reason to use water leaving radiance is that, it will help you easily identify chlorophyll, suspended solids, waste discharge and oil spills in large dynamically changing ocean.
Why not Albedo: If you are willing to use Albedo, then the parameters such as Sun's angle, angle of sensor to equator and surface quality of water are required to prove your claim of findings and ground truth verification.
Albedo can be suitable for still waters or water with less dynamic changes. But again it can be case specific if you choose sea without waves.
Therefore, you can compare the RS data variation between calm and roaring seas of the same region to extract new findings.
@ Girish Patidar , My apology first! Apparently, I did not make the question clear. The question is why not use water-leaving irradiance instead of water-leaving radiance, the former is the hemispherical integration of the latter, thus should conveys more information about the ocean
Dear Blowman,
This link provided below may be useful for you. Because its ocean colour, they need the parameters below water surface. Even colour may be surface property, but it is dependent on contents of water.
https://gis.stackexchange.com/questions/222554/difference-between-irradiance-and-radiance-remote-sensing-reflectance-and-water
@ Gopikrishnan .T , thank you for your reply! The link you provided above explains the relationship between the water-leaving reflectance and the remote sensing reflectance, which assumes water-leaving radiance is isotropic for all steradians, in another word, it assumes the water surface is a lambert reflector. In this way, the BRDF effects of water is simplified, is there any justification for this assumption?
I have to find it. If you come across such explanation post me the link. Thank you.
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