This application constructs Sentinel-2 cloud-free composites of different periods and allows to visualize different three bands combinations. The main steps are (1) filtering, (2) cloud masking, (3) compositing, and (4) visualization.
The application allows filtering Sentinel-2 imagery by specifying the period (by default 2018-07-01/2018-08-31) and the Maximum percentage of clouds in the image (by default, 70%). Clouds are masked out from all remaining imagery using the Sentinel-2 cloud probability dataset available at https://developers.google.com/earth-engine/datasets/catalog/COPERNICUS_S2_CLOUD_PROBABILITY. The Maximum probability that the pixel is cloudy slider defines the value above which pixels are considered cloudy and removed from the imagery. The final cloud-free composite is generated by clicking the run button and is calculated as the median of all remaining valid observations.
By default, a false-color composite is visualized (“red”, “green”, and “blue” bands are selected). To visualize a single band in greyscale, for example, “blue”, select “blue” in all three selectors. For some suggestions of Sentinel-2 bands, combinations see https://gisgeography.com/sentinel-2-bands-combinations/.
This application is a demo developed by Saverio Francini and presented in the Google Earth Engine Training and Networking Day. The video of the event will be available here soon. The whole code presented in the demonstration, as well as the code of the application, are available at https://code.earthengine.google.com/?accept_repo=users/sfrancini/GEEnetworkingDay.
The application is available at https://saveriofrancini.users.earthengine.app/