Geometric parameters: Azimuth and Incidence angle

Dear SAR friends,

I want to ask for your help in solving a problem with geometric parameters. I would really appreciate if you can help me.

I would like to know if there is currently any way to have the value in degrees of azimuth and incidence angle. I have tried everything they have written on similar topics, but I cannot solve it (even in metadata).

Many thanks!

Regards!

as the sensors have different metadata - what data are you working with?

Sorry for not indicating it and thanks for your reply. At the moment, with Sentinel 1. what happens is that I review in metadata but the value of these (in degrees) is not indicated. The incidence angle (near / far) indicates 999999 and I do not know which to use, if the near or far in the case of having a correct figure. On the other hand, the azimuth angle is not indicated anywhere.

Many thanks!

Regards!

Did you import the data correctly with File > Import and select the .safe file?
There should also be an incidence angle band under tie point grids.

It should look like this: Subsidence map in 3d view

Thank you very much for your reply! Yes, I have tried to do that but I think it is an image problem. For the other question about the incidence angle, do you know where I can get that data in degrees?

Thank you very much!

Regards

I was actually referring to the incidence angle.
Can you name the S1 product name what you are using?

Dear Abraun,

Thank you very much for your response and sorry for responding late. This is the image I use

S1A_IW_SLC__1SDV_20171013T052724_20171013T052751_018790_01FB7E_434C

I don’t know why, but I loaded it again and the incidence angle does appear. I appreciate your help.

Do you know how I could estimate the incidence angle of that image or any other of S1?

Thanks for your help.

the “incidence angle” is present in the metadata of any Sentinel-1 product and as a raster.
But Sentinel-1 SLC products are divided into three swaths because of the TOPS acquisition principle: https://sentinel.esa.int/web/sentinel/user-guides/sentinel-1-sar/acquisition-modes/interferometric-wide-swath
So there is an incidence angle for all three swaths (and both polarizations in case of the metadata).

grafik

If you download the GRD product, you only have one raster product and one incidence angle.

Or are you talking about the “local incidence angle” which considers the underlying topography: grafik
source

This can be estimated the terrain correction modules and given as an additional output (example here).

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Dear ABraun

Thank you very much for your response, I really appreciate your kindness. I only have one question left and I don’t take more of your time. Do you know how to have the value in degrees of the angle of azimuth?

Thank you very much!

Best regards

I’m not entirely sure, but this is how you can search for it:

Dear ABraun,

I appreciate your kindness in answering my questions. Thank you very much!

Have a nice day,

Best regards

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Do you know how to estimate the azimuth angle of S1 GRD or SLC?

Did you already check these topics?

I have checked these topics. I only get the look direction with a cyan arrow overlaid on the image by the step of adding the mapping tools layer in SNAP. But I want to get the azimuth angle for every cell of S1. I cannot find any method to get a quantitative value for every cell of the image.

I think you search something like platform heading (Satellite azimuth heading angle for ERS) or azimuth heading (Satellite azimuth heading angle for ERS and Heading and azimuth angle).
Based on these discussions, it is constant for all pixels in an image.

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Thank you very much! :grin:

Hi everyone,

I need “satellite heading” value of the Sentinel-1 images to combine asc. and desc. images for the calculation the vertical component using the equation given below;

Therefore, is it possible to guide me to gather this information?
Thank you already.

Hello hiny, have you solved this problem? I’m now having this problem too, and I want to extract the angle of incidence information of sentinel-1 data with latitude and longitude information. How does this need to be achieved? Thank you very much.

Hello, ABraun. The problem I have now is that I want to use SNAP software to extract the radar incidence angle of Sentinel-1 data, how to extract it, and look forward to your suggestions. (In fact, I have used “band mathematics” to extract the radar angle of incidence information, but there is no latitude and longitude information, how to export radar angle of incidence information, including latitude and longitude), thank you very much for your technical support

You can include the local and global indicence angle as a separate band in the Range Doppler Terrain Correction step.