Data level distinction?

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leon_c
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Data level distinction?

by leon_c » Thu Nov 24, 2022 4:30 am America/New_York

Hi!
I'm having some trouble grasping the distinction between data levels and actual physical interpretation of data.
Say we are talking about chlorophyll concentration: level 1 would include both radiance L (power of the light radiation at specific wavelength per unit solid angle per unit area) and reflectance R (ratio of specific radiance/iradiance, no need to get specific), while level 2 would be chlorophyll concentration for a given swath obtained by applying the algorithms (contained within l2gen) to the appropriate level 1 data.
Am I understanding this correctly?

Thanks!

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OB.DAAC - amscott
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Re: Data level distinction?

by OB.DAAC - amscott » Fri Nov 25, 2022 10:39 am America/New_York

Hi, Please take a look at our product descriptions page:
https://oceancolor.gsfc.nasa.gov/products/

leon_c
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Re: Data level distinction?

by leon_c » Fri Nov 25, 2022 10:43 am America/New_York

Hi!
Thanks for the reply. I'm aware of the documentatiton, but the term "geophysical" is still too vague to me and doesn't really help me place radiance and/or reflectance into level 1 or 2...

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Re: Data level distinction?

by OB.DAAC - amscott » Fri Nov 25, 2022 11:09 am America/New_York

The algorithm descriptions are meant to provide extra detail and they have links to papers at the end of each. Are they helpful? Your question feels familiar.There might have been a past question on the forum from a previous user. If I find it, I will post the link here.

If the algorithm doesn't help, would you like to be referred to other resources? Is there something we can do to improve the existing documentation for you?

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Re: Data level distinction?

by leon_c » Fri Nov 25, 2022 12:07 pm America/New_York

Combining the two sources it is implicitly implied that L is the only level 1 physical variable, everything else is level 2. Thanks!

As for suggestions, I reckon some tacit examples of data levels in the documentation would be of great use.
Thank you once again! :D

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