How to Transform L1C to L2A from Sentinel-2 Imagery

L1C (Level-1C) data from Sentinel-2 contains the raw data that has been radiometrically and geometrically corrected but is still in its original sensor geometry. L2A (Level-2A) data, on the other hand, has undergone atmospheric correction, and is in the corrected geometric and radiometric form.

To convert L1C data to L2A data for Sentinel-2 imagery, you can follow these steps:

1. Download the Sen2Cor software from the ESA’s website (https://step.esa.int/main/third-party-plugins-2/sen2cor/sen2cor_v2-8/). Sen2Cor is an atmospheric correction software designed specifically for Sentinel-2 imagery.
2. Install the Sen2Cor software on your computer following the installation instructions provided by ESA.
3. Once installed, open the command prompt (for Windows) or the terminal (for Linux or Mac) and navigate to the directory where your Sentinel-2 L1C data is located.
4. Run the following command:
5. L2A_Process <path to L1C data>
6. Replace <path to L1C data> with the path to the directory containing the L1C data.
7. Sen2Cor will then perform atmospheric correction on the L1C data and output the L2A data in the same directory as the L1C data.

Note that the atmospheric correction process can take a significant amount of time depending on the size of your Sentinel-2 imagery, your computer’s processing power, and other factors.