Radiometric calibration with SNAP
From AWF-Wiki
(Difference between revisions)
Line 1: | Line 1: | ||
+ | = Prerequisites = | ||
* Download a Sentinel-2 Level 1C tile from ESA's Copernicus Open Access Hub web service as a compressed zip file: [[Downloading Sentinel-2 images]]. | * Download a Sentinel-2 Level 1C tile from ESA's Copernicus Open Access Hub web service as a compressed zip file: [[Downloading Sentinel-2 images]]. | ||
* Start SNAP Desktop. | * Start SNAP Desktop. |
Revision as of 14:50, 11 November 2020
Prerequisites
- Download a Sentinel-2 Level 1C tile from ESA's Copernicus Open Access Hub web service as a compressed zip file: Downloading Sentinel-2 images.
- Start SNAP Desktop.
- File --> Open Product.... Browse to the zip archive or drag and drop the file from the Windows file explorer into the SNAP tab Product Explorer.
- Optical --> Thematic Land Processing --> Sen2Cor Processor --> Sen2Cor 280
- Specify the Processing Parameters. Details can befound in the Sen2cor manual. Default settings are the same used for L2A processing.
A first run will be made with 60m pixel resolution. Computation time dependes mainly on the number of available CPUs on your local machine. Increase the NB Threads accordingly to speed up parallel processing. Topographic normalization is activated with DEM correction: TRUE. For DEM directory specify a folder where dem files are downloaded.
- Check Display execution report on. Run...
- Compare Output Product with Original Product. Mark the Original Product Name in Product Explorer Right Click Open RGB Image Window --> Sentinel-2 MSI Natural Colors. OK. Repeat for the Output Product.
- Window --> Tile horizontally
- Check View --> Synchronize Image Cursors and View --> Synchronize Image Views. Zoom and Pan.
- Activate a map view by clicking into the canvas of the Original Product. Click Mask Manager tab on the right.
- Check the mask layers opaque_clouds and cirrus_clouds in the Mask Manager.
- Click into the map canvas of the Ouput Product. Click Mask Manager tab on the right.
- Check the mask layers scl_cloud_shadow, scl_cloud_medium_proba, scl_cloud_high_proba, scl_thin_cirrus in the Mask Manager.
- For second run choose in Processing Parameters: Spatial Resolution: 10 (m). Be patient, processing takes some time ...