Mixed spectral returns

A spectral mixture occurs when “[t]he signal detected by a sensor into a single pixel is frequently a combination of numerous disparate signals.” (gipsa-lab, n.d.) In other words, mixed pixels typically exist “when distinct materials are combined into a homogeneous mixture.” (gipsa-lab, n.d.) For example, a mixed pixel can represent vegetation and soil or soil and rocks. (gipsa-lab, n.d.)