Sensor Viewing Angle Definition

development
1

Hi all,

I have a problem regarding the sensor viewing incidence angles that are provided in the meta xml file of the granules.

Is there any documentation or definition of what the azimuth and zenith exactly refer to?
How do the bands work that are present in the azimuth data? Why are there big gaps between the azimuth values per detector id?

Lasty, a question on a different topic. Is there any information of the exact longitude and latitude at which the satellite was at the moment of sensing/capturing the image?

Thanks in advance!

Thymen

2

This is a good question. There is no good official documentation.
See my question and the answer by @Chenocq.

Also. the help page for the S2 resampling might help.
And you might be interested in my blog article about the sentinel-2-geometry-up-scaling feature in the EOMasters Pro Toolbox.
There is ephemeris information in the metadata, but I don’t know how to use them. Maybe you know. See Sentinel-2 Products Specification Document page 127ff.

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3

Thank you for your answer Marco.

The ephemeris help a lot.

Did you, or anyone else, experience problems with the viewing sensor angles? Even with the proper azimuth definition the results do not make sense to me. I am trying to solve for the parallax effect created by objects at higher altitudes. But the azimuth angles are often not even close to being close to correct in my case.

Is this a problem on my implementation side? Or did others face similar issues?

Kind regards,

Thymen

4

I’m sorry. I haven’t used the angles in such details. Maybe someone else can help?