Calculations of the Soil Hot-Spot Effect Using the Coherent Backscattering Theory

T h e shadowing theor~j has been widely used to account fi~r the hot-.spot effect fi~r the canopy and soil. However, it is not valid for soils' that are composed of fine particles and &~ not have weU-defined shadows. The coherent backseattering theorTj is used in this study to calculate both the nuzgnitude and the angular width of the hotspot peak .fi~r clay and silt soils'. The .soil hot-spot magnitade is calculated by solving the vector radiative transfer equation. The dense nature of the soil medium is taken into account in the calcnlations of the hot-spot angular width. The results are also linked with the Hapke hotspot empirical fimction. The effects of the wavelength dependence and ~f particle size and shape als'o are examined. ©Elsevier Science b~c., 1997