Procedure for reading sentinel images

Optical Toolbox
#1

Hello; I am a new user of sentinel images
Please can you give me the procedure for reading sentinel images on snap?
Cordially

Welcome to the Sentinel Toolbox Exploitation Platform Forum
#2

Actually you can open the files as in any other application, like imaging applications.
Just go in the menu to File / Open Product… or click directly on the first button () in the toolbar.
Or do you have any specific question/problem?

#3

Thank you;

I cannot visualize the images in the interface of Snap as you can see the screenshot.

cccccc.JPG1201×497 90.9 KB

Another question, about calibration of the images, DN number, How can I recover the reflectance in this images?

Thanks

#4

Do you use the latest SNAP version? From looking at the exception message I guess it is not the latest. But maybe it is also possible that the product is corrupt.
For Sentinel 2 data the values are shown as toa reflectance by default since version 4.0.

#5

I tried with the version .4. for 64 bits and 32 bits, but it is the same result!!!

You sad that Snap v 4.0 show the reflectance value directly!

If I use another software like ENVI, QGIS, I need to calibrate the images!!!

Thanks

#6

Hi @siham1987,

Have you tested with different products? Have you downloaded the product from scihub?

#7

Hello;

I have dowloaded images from scihub, and I have tested 4 images at least!

#8

Sincerely, i do not know what is the origin of the error.

The exception is launched when you open the image or when you try to visualize any band?
Have you unzipped the full product before trying to open it?
Could you tell me the name of one of the products to download it?

#9

S2A_OPER_PRD_MSIL1C_PDMC_20160715T190510_R122_V20160715T100616_20160715T100616.SAFE

I unzipped the file and I tried to read 4 images!!!

#10

Hi @siham1987,

I am not able to reproduce the error with that image, i have downloaded it and i can read it correctly.
Please, could you answer some questions to be able to understand what is happening:

  1. What are the available readers when you open the product?
  2. What folders and subfolders are created in the product explorer?
  3. In Tools -> Options -> Performance , what is the cache path? Has been generated any subfolder there?
  4. Are you able to read correctly one jp2 image of the product from SNAP? Try File -> Open Product… and select for example:
    S2A_OPER_PRD_MSIL1C_PDMC_20160715T190510_R122_V20160715T100616_20160715T100616.SAFE\GRANULE\S2A_OPER_MSI_L1C_TL_SGS__20160715T170030_A005553_T31QGB_N02.04\IMG_DATA\S2A_OPER_MSI_L1C_TL_SGS__20160715T170030_A005553_T31QGB_B01.jp2

I am sorry for so many questions but if i cannot reproduce the error, it is the only way to help you.

#11

Dear Sir;

I thank you for your effort, I tried many time to read the images, but it is the same result;

So, I unzip the file with another software, and I success to read it; so the problem I think when I unzip they missed a file, and they cannot be opened!!!

Capture11.JPG1365×685 163 KB

I read and visualize, but when I tried to export the image they display an error!!!

I am too sorry for many questions!!!

#12

Don’t worry about the questions. I think they are justified.

To write the data to GeoTiff you need to resample the product to a common resolution.
Different resolutions are not supported for writing.
Use from the menu Raster / Geometric Operations / Resampling and define the resolution of your choice and save the resulting product.

#13

Dir Sir;
I tried this but the file is too heavy and the software refuses to export it, so I tried to decline the size by clicking subset, but when I try to view an other software, it appears black!!!

#14

If you choose BIG-GeoTIFF as export format if the amount of data is more than 4GB it should actually work.
What message do you see when SNAP refuses to export it? Can you open the exported data in SNAP? Which other software do you use?