Nonlinear spectral mixing in desert vegetation

Linear miring models are widely used in terrestrial remote sensing, with the errors in these models being often attributed to ''nonlinear'' mixing. Nonlinear mixing refers to the interaction of light with multiple target materials. Reflectance data from creosote bush in the Manix Basin of the Mojave Desert is used to show the existence and importance of nonlinear mixing in arid region vegetation. It shows that the difference in the reflectance spectrum of plants against a soil background and the spectrum of the plant against a dark background is well represented by light that has interacted with both the soil and the plant.