Good morning everyone,
I am here to ask an opinion about a weird result I obtained from the spectral unmixing of a Sentinel2 image.
I have already worked with SMA on Sentinels, but this is the very first time something like this happens.
I selected three spectral signatures from the image (one for vegetation, one for soil and one for water).
I then launched the SMA, a Fully Contrained done with all the three spectral signatures. The output gave me three bands, one for each spectral signature. However, while the bands for vegetation and soil looked normal, the band with the abundance of water was empty: the value of the pixels of the band is 0 everywhere.
If I understood correctly the theory behind SMA, this shouldn’t happen, because at least the pixel from which I took the spectral signature should have a value higher than 0.
Am I right? Someone has got any explanations for this?