Get time series data for a specified variables from S-3 SLSTR?


#1

Hi,

I recently looked into data from Sentinel 3 in SNAP. I download the 500 Mb file and open it.

I am interested in the skin_temperature variable for a specific location over time. Now, if I want to get that information, I need to download that 500Mb file for each date in my period, and look up that specific number. That is not very efficient.

So I am interested if there is a way to query that. And if so how. Or is there an API through which I can access that?

Thanks! Hope someone can help


#2

You can’t do a subset when downloading, but if you are interested in one (or several) single geographic location(s) it might be more convenient to use the Pixel Extraction tool (Raster->Extract Pixel Values) to retrieve this. As the Pixel Extraction Tool requires all bands to be of the same raster size, I suggest to open the products in 500m- or 1km-resolution in SNAP Desktop first. The Pixel Extraction can also be called from the command line.
Does this help you?


#3

Tonio,

Thank you for replying.

I saw the tool and it definitely seems useful. Very convenient indeed, as I am interested in specific locations yes!

I didn’t fully understand - I can only use the tool, once I have downloaded the files that contain the data I am interested in - is that correct? And this means that I can’t only download data I am interested in using filters, but have to get the whole dataset, and then once I have it on my hard drive, derive the information I need?

Yuli


#4

You’re correct with both assumptions: You need to have the data on your hard drive. And you can’t create a variable subset before downloading, so you have to download the whole product.


#5

I see.

How can i specify which parameter i want to export? I cant see that option.
And also, if i load two products for covering the same location for 2 different days, would I be able to export data for both dates for a specific location?


#6

You can’t choose individual variable names. You can choose to export bands, tie point grids or masks. skin_temperature is a tie point grid. so you have to check that and uncheck the others.
And yes, the Extraction Tool will get the value for products of different dates. Just make sure not to use a time difference constraint.