How to extract value from sentinel 3 OLCI maps for a specific point.?

snap
#1

Hello, so I have successfully created OLCI maps (Chlorophyll maps). Now I wanted to know if it is possible to
extract the value from a specific point or area. Can anyone provide any insight? I have never done it so unable to get clues from previous similar questions.

Thank you :slight_smile:

Sincerely
Rocktim

#2

There are actually two ways to do it. One is for doing it on a single scene and one for doing it on a bunch of scenes.
You can add Pins image. In the Pin Manager image you can configure the displayed data image and then you can export image it to text file.

Pins are also explained in this short Video Turorial.
You can find more tutorials like this on our tutorials page:

If you want to do it on several scenes for a multiple locations you can use the PixEx tool.

You can find it at Raster / Export / Extract Pixel Values
This tool can also be used from the command line.
For more information on this tool, please have a look at the help pages.

image
image.png776×815 81.3 KB

3 Likes
Extract pixel values
Export values from Sentinel 2
Extract the backscatter coefficient value
Removing pin leads to SNAP getting stuck
Pixel extraction tool
TopSAR Processing
Batch procesing
Export values from Sentinel 2
Time Series from Multiple Pins
Backscatter normalization to a pre-defined incidence angle for S-1 GRD HH channel data
Threshold Standardization in S1 data?
Help contents incomplete
#3

Dear Marpet

Thank you for your continuous advice and response.
I will have a look and see if I can extract the values.

Sincerely
Rocktim

#4

Hey Marpet, thank you for this explenation!

When using the PixEx Tool, there is a problem for me, maybe you or someone else can help me with.
I made temperature Images for the City of Cologne and now i want to extract Pixel Values from the Rhine River. So i made 7 Pins in the River in one Scene and opened the Pixel Manager. Here i configured the Pixel Data like you said, to see the °C Temperature Values for my Pins:

PixelManager1
PixelManager11919×1080 807 KB

After this i used the ‘Transfer the selected Pins to other products’ symbol to have the pins at all my 3 Scenes. Now i configured the displayed Data on each of them again, to see the °C here also.
PixelManager2
PixelManager21913×1018 683 KB
(For [3] i made no Screenshot, but here it looks the same)

(1/3)

#5

After this i used the PixEx tool like this:

1
1748×788 54.4 KB
2
2767×795 114 KB

#6

Now i expected to see the °C Values for each Scene in the Result, but it looks like this:

Result
Result1427×779 49 KB

So the °C Values are only displayed for one product, the other ones are filled with 1.
Can you explain me where the problem could be? Your help would be really apreciated.

Thanks in Advance,
Paul

#7

That’s strange. I have no idea.
For me it looks like the ones belong to the last column and the °C_neu has no value.
If you enable the display of control character like linefeed in your editor, you might see it.
I think the default notepad in Windows can’t do it.
I would suggest an editor like Notepad++ or pspad.

@abruescas Do you have an idea?

#8

Thanks for your quick response. You are right, in notepad++ it looks like this:

Result1
Result11192×588 24.3 KB

#9

Could you click on this little button in the tool bar?
image
Then the control characters are shown.

#10

CC
CC1740×331 25.9 KB

#11

That’s a different file! This is the pin export.

#12

I’m sorry, this is the right one:

CC1
CC11305×657 26.8 KB

#13

There you see 2 tabs. So, this column is skipped. This can happen if the data is not valid at this location. However, the images you have posted indicate valid data.
What happens if you remove the first product and let the extraction run only on the two other products?