Sentinel 3A Altimetry Data Processing

I dont know how to retrieve water level from sentinel 3A’s SRAL altimetry data. I’m currently using the level-2 LAN product. Tried a few formulae cominations in python, nothing worked out good. Wondering if i can do this possibly in SNAP toolbox.

Any help would be greatly appreciated. Thanks

I would suggest to take a look at BRAT.

It is the altimetry toolbox from ESA & CNES.

Thanks for replying sir.
Yes sir, I’ve installed BRAT too. And i can see the quick processing options that are available. But sir, can you please guide me how to calculate water level for an inland water body applying all corrections using BRAT.

I’m just getting it messed up around many formulas and I’m not sure which is the right one.

If possible, I can also send you the python code i’ve written to read and process the .nc file of SRAL __LAN product.

Thanks, so much, sir.

I never used BRAT so I can’t help you with it.
But they have there own forum. You will probably get the best help there.

You can use :
This is a open source software that under development. The functions to calculate the water level over lakes is finished.


Hi Marco,

I am trying to download BRAT using link that you provided. However, that link is not working. Do you know any alternative link from where I can download BRAT? Also, you mentioned about BRAT forum but I could not find any where I can post my question.

Thanks for your help!

It seems that the links are not working right now
Maybe you could ask to esa helpdesk.

Sorry, I have no other source.
Maybe the page is only temporarily down and will be back online soon. I don’t know.
You can ask the help desk as @abruescas suggested or you mail directly to

Thanks Marco!
I will contact the helpdesk as @abruescas suggested and also email directly.

I am also using Sentinel-3 SRAL in BRAT for inland water body monitoring. The azimuth resolution is said to be 300 m but the output in BRAT has a resolution of 38 km, why is it so?

As said earlier in this thread. It is better to ask the guys from BRAT directly.
HelpDesk – Radar Altimetry Tutorial and Toolbox