VI NDVI visualisation script
//VERSION=3
// This custom script visualises raw NDVI values
function setup() {
return {
input: ["NDVI", "dataMask"],
output: { bands: 4 }
};
}
const map =
[[-1, 0xFFFFFF],
[-0.5, 0xFEFEF3],
[0.00, 0xFFFFE5],
[0.10, 0xF7FCB9],
[0.20, 0xD9F0A3],
[0.35, 0xADDD8E],
[0.50, 0x78C679],
[0.65, 0x41AB5D],
[0.80, 0x238443],
[0.90, 0x006837],
[1.00, 0x004529]
]
const visualizer = new ColorMapVisualizer(map);
function evaluatePixel(sample) {
let rgbVis = visualizer.process(sample.NDVI * 0.0001);
return rgbVis.concat(sample.dataMask);
}General description of the script
This script visualises raw NDVI of the VI product. NDVI quantifies vegetation photosynthetic capacity by measuring the difference between the Near-Infrared (NIR) (which vegetation strongly reflects) and red spectral bands (which vegetation absorbs). Although it is not a physical property of vegetation cover, NDVI is widely used as an indicator for live green vegetation monitoring.
Physical values range from -1 to 1.he color map is adopted from https://github.com/jacobs-tim/copernicus-land-monitoring-service-hrvpp-colourmaps
Description of representative images
August, 2020 NDVI over South Tyrol Northern Italy
