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Obtaining Satellite Image Observation Viewing Angle and Albedo Conversion

Posted: Tue Jun 24, 2025 4:23 am America/New_York
by liren
I am currently engaged in an endeavor to convert the L2A reflectance images of EMIT into albedo (hemispherical reflectance, to be precise). To achieve this conversion, I intend to utilize the BRDF function. In this process, I require the sensor viewing angle and the zenith angle.
However, I have noticed that the L2A data does not provide information regarding the sensor viewing angle and the zenith angle. While I contemplate the possibility of calculating the zenith angle based on the ___location and time, I am uncertain about where to obtain the sensor viewing angle. I'm wondering if it could be assumed to be perpendicular to the Earth's surface? I have thoroughly studied the algorithm documentation but have found no relevant records.

In addition to this, I am curious to know if EMIT has any plans to develop albedo products.

Re: Obtaining Satellite Image Observation Viewing Angle and Albedo Conversion

Posted: Tue Jun 24, 2025 10:12 am America/New_York
by LP DAAC - lien
Hello,
The viewing angles for the EMITL2A are contained in the corresponding EMIL1BRAD product and they are contained in the Observation layer within the L1BRAD. Please see the different layers and the index for the Observation layer on the L1BRAD product page: https://doi.org/10.5067/EMIT/EMITL1BRAD.001

I have not heard of plans for an Albedo product yet. However, if you sign up for our listserv you will receive information on products and other information when it becomes available. Just send a blank email to: lpdaac-join@lists.nasa.gov
Please let us know if you have further questions.
Thanks,
Brett