Using EO Browser I’ve downloaded the NDVI index,
why the geotiff 32bit has 3bands and not a unique band with the NDVI value of the pixels ?
Is possibile to obtain a one band raster? Or which of the 3 bands is the correct one ?
many thanks
Simone
Using EO Browser I’ve downloaded the NDVI index,
why the geotiff 32bit has 3bands and not a unique band with the NDVI value of the pixels ?
Is possibile to obtain a one band raster? Or which of the 3 bands is the correct one ?
many thanks
Simone
Hi Simone
You get 3 bands because NDVI layer in EO browser is a visualized layer therefore has RGB bands.
Yes it is possible to download only 1 band with actual NDVI values on EO browser.
Please refer to this thread for a detailed answer.
You need to first create your custom layer using this script below which returns 1 NDVI band
//VERSION=3
function setup() {
return{
input: [{
bands: ["B04", "B08"]
}],
output: {
id: "default",
bands:
}
}
}
function evaluatePixel(sample) {
let ndvi = (sample.B08 - sample.B04) / (sample.B08 + sample.B04)
return [ ndvi ]
}
hope that helps, otherwise feel free to ask further questions
Hi @meteoclima,
Sorry, there was a typo in @dorothyrono’s code: it is missing the parameter that sets the output number of bands, which in this case should be 1.
If you try the following Evalscript, it should work (see example):
//VERSION=3
function setup() {
return {
input: ["B08", "B04"],
output: { bands: 1 }
};
}
function evaluatePixel(sample) {
var ndvi = (sample.B08 - sample.B04) / (sample.B08 + sample.B04);
return [ndvi];
}
Note: this script in itself is designed for display purposes (scaled to the range 0-255). However, when you select Image format: TIFF (32-bit float)
in the download section of EO Browser (under Analytical
) the system will retrieve the raw values in Float for you.
Hello,
thank you very much. Yes It works fine! great!
Best Regards
Simone