Is the GRD data from AWS thermally corrected?

Sentinel@AWS
1

Hello,

Is the Sentinel-1 GRD data from AWS thermally corrected (i.e., has thermal noise already been removed from it)? I’m talking about the data mentioned at Sentinel-1 GRD dataset .

Thanks,
Soni

2

Hi Soni,

Shortly, yes. For more details check out Seninel-1 Processing Chain chapter in our documentation.

Cheers, Anja

1 Like
3

Perhaps useful additional point to what Anja stated.
The data stored on AWS bucket are not processed in any way, i.e. they contain the same values as the original data produced by ESA[1]. The original values do not have thermal noice removed, but you have all the accompanying auxiliary data available to do so.

If you need data without the thermal noise, we would recommend using Sentinel Hub service, which does this, as Anja mentioned below.

Best,
Grega

[1] The only change is COG-ification of the GeoTiffs, but this is done in a way to keep original values intact.

1 Like
4

Thanks, Anja and Grega, for the information.

So the actual dataset that I’m interested in using is the Digital Earth Africa (DEA) Sentinel-1 SAR Backscatter data at Sentinel-1 SAR Backscatter — Digital Earth Africa 2021 documentation .

The parent data of this DEA data is the AWS Open Data Registry at Sentinel-1 - Registry of Open Data on AWS . The documentation of this AWS Registry is the link that I posted in my original question, which you have already clarified doesn’t have thermal noise removed.

Now another confusion that I have that the DEA Backscatter link that I posted in the initial paragraph above also mentions that it “is processed by Sinergise Sentinel Hub using ESA Sentinel-1 GRD as input”. Is the Sinergise Sentinel Hub the same as the Sentinel Hub service that Anja mentioned that does do the thermal noise removal? If so, then this looks like contradicting information.

Thanks,
Soni

5

Ah, i see. Things are more complicated than as they seem, but on the good side this time.
DEA Sentinel-1 SAR is CARD4L-ready dataset, processed with Sentinel Hub, and this one actually does have thermal noise removed.
So, DEA S1 SAR <> “core” AWS S1 GRD

Therefore, if you are using DEA SAR, then you are good - thermal noise is removed.

1 Like
6

This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.