Preprocessing Sentinel-2 with SNAP
From AWF-Wiki
(Difference between revisions)
(→Reading a Sentinel-2 tile) |
|||
| (27 intermediate revisions by one user not shown) | |||
| Line 1: | Line 1: | ||
| − | = | + | =Reading a Sentinel-2 tile= |
| − | # Download a complete Sentinel-2 tile from ESA Open Access Hub. | + | # Download a complete Sentinel-2 tile from ESA Open Access Hub (see [[Downloading Sentinel-2 images]]). |
# Start SNAP Desktop | # Start SNAP Desktop | ||
| − | # {{mitem|text=File --> Open Product... | + | # {{mitem|text=File --> Open Product...}} Browse to the compressed Sentinel-2 zip file. {{button|text=Open}} or drag and drop the zip file from Windows File Explorer into the SNAP '''Product Explorer''' tab. |
# Click on the plus sign of the file name in Product Explorer. Unfold Metadata and Bands. | # Click on the plus sign of the file name in Product Explorer. Unfold Metadata and Bands. | ||
| + | [[File:snap_product_explorer.png|400px]] | ||
| − | = | + | =Displaying a Sentinel-2 tile= |
| − | # Mark the file name in the '''Product Explorer'''. Right click {{button|text=Open RGB Image Window)}}. In the Profile drop-down list select '''Sentinel 2 MSI False Colour Infrared'''. {{button|text=OK | + | # Mark the file name in the '''Product Explorer'''. Right click {{button|text=Open RGB Image Window)}}. In the Profile drop-down list select '''Sentinel 2 MSI False Colour Infrared'''. {{button|text=OK}} |
| + | [[File:snap_band_select_rgb.png|400px]] | ||
=Resampling= | =Resampling= | ||
| − | + | The spatial resolution of all satellite bands should be resampled to a unique pixel size (10m) to simplify the processing workflow. | |
| − | + | {{mitem|text=Raster --> Geometric --> Resampling}}. Open the '''Resampling Parameters''' tab. Define size of resampled product: check '''by reference band from source product'''. Select '''B2''' from drop down list. {{button|text=Run}}. | |
| − | + | ||
| + | =Subsetting= | ||
| + | '''Spatial subset''' | ||
| + | * Mark the file name of the resampled product from previous work step in '''Product Explorer'''. | ||
| + | * {{mitem|text=Raster --> Subset..}} | ||
| + | * Left click in the preview of the Specify product subset dialog. | ||
| + | * In the ''Spatial Subset'' tab draw a box on top of the preview image and move it to your region of interest. | ||
| + | * Make a note of '''Pixel Coordinates'' and (Geographical)''' Geo Coordinates''' if you want to repeat this step with other acquisiton dates of the same tile. | ||
| + | [[File:snap_specify_subset.png|400px]] | ||
| + | '''Spectral subset''' | ||
| + | * In Band Subset tab click '''Select none''' and then check only the multispectral Reflectance Bands (B2,B3,B4,B5,B6,B7,B8,B8A,B11,B12). {{button|text=OK}}. | ||
| + | [[File:snap_specify_band_subset.png|400px]] | ||
| + | |||
| + | =Write to permanent file= | ||
| + | Mark the subset file name in '''Product Explorer'''. | ||
| + | {{mitem|text=File --> Export --> GeoTIFF}}. Click {{button|text=Export Product}}. | ||
[[Category:SNAP Tutorial]] | [[Category:SNAP Tutorial]] | ||
[[Category:Tutorials]] | [[Category:Tutorials]] | ||
Latest revision as of 12:32, 9 November 2020
Contents |
[edit] Reading a Sentinel-2 tile
- Download a complete Sentinel-2 tile from ESA Open Access Hub (see Downloading Sentinel-2 images).
- Start SNAP Desktop
- File --> Open Product... Browse to the compressed Sentinel-2 zip file. Open or drag and drop the zip file from Windows File Explorer into the SNAP Product Explorer tab.
- Click on the plus sign of the file name in Product Explorer. Unfold Metadata and Bands.
[edit] Displaying a Sentinel-2 tile
- Mark the file name in the Product Explorer. Right click Open RGB Image Window). In the Profile drop-down list select Sentinel 2 MSI False Colour Infrared. OK
[edit] Resampling
The spatial resolution of all satellite bands should be resampled to a unique pixel size (10m) to simplify the processing workflow. Raster --> Geometric --> Resampling. Open the Resampling Parameters tab. Define size of resampled product: check by reference band from source product. Select B2 from drop down list. Run.
[edit] Subsetting
Spatial subset
- Mark the file name of the resampled product from previous work step in Product Explorer.
- Raster --> Subset..
- Left click in the preview of the Specify product subset dialog.
- In the Spatial Subset tab draw a box on top of the preview image and move it to your region of interest.
- Make a note of Pixel Coordinates and (Geographical)' Geo Coordinates if you want to repeat this step with other acquisiton dates of the same tile.
Spectral subset
- In Band Subset tab click Select none and then check only the multispectral Reflectance Bands (B2,B3,B4,B5,B6,B7,B8,B8A,B11,B12). OK.
[edit] Write to permanent file
Mark the subset file name in Product Explorer. File --> Export --> GeoTIFF. Click Export Product.
