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Hello,


I want to know the value of every color band.

I know that:



CoastalBlue=431 - 452nm

B=465 - 515

G1=513 - 549

G2=547 - 585

Y=600 - 620

R=650 - 680

RedEdege=697 - 713

NIR=845 - 885



But when I try to know the value of them it is not the same. Example:



evalscript = """
//VERSION=3
function setup() {
return {
input: [{
bands: ["Green"],
units: "DN"
}],
output: {
id: "default",
bands: 1,
sampleType: SampleType.FLOAT32
}
};
}


function evaluatePixel(sample) {
var green = sample.Green
return [green];
}


The result it isn’t between G1=513 - 549, G2=547 - 585.

I want to know please value of each band.


Regards Antonio

Hello Antonio,


I think there is a misunderstanding among three concepts: wavelengths, digital numbers (DN) and reflectance. From your question it seems you want to retrieve wavelengths. You can access this data reading the documentation of the dataset you are interested in (e.g., Landsat 7, Sentinel 2, SPOT, etc.). You won’t get this information by clicking on the pixels. Wavelengths vary depending on the bands that the selected sensor is sensitive to. For further information on this, you can refer to the following link: Newcomers Earth Observation Guide | ESA Business Applications


It’s not possible to retrieve wavelengths from the pixels, but you can get DN. In the case of Sentinel-2 L2A, DN are calculated based on the reflectance. DN = 10000 * REFLECTANCE


We have a dedicated ”Data” section, where you can get information of every dataset: https://docs.sentinel-hub.com/api/latest/data/


Finally, you can explore the Units in which the data is delivered by clicking on Units as shown in the image below:


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