![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
Abstract
The thermal microwave emission of media with dense distribution of particles is studied. A general relation, that holds for media with nonuniform as well as uniform temperature distribution, is first derived between active and passive remote sensing. The brightness temperature of passive sensing is proportional to the integration of the product of the temperature distribution and the divergence of the Poynting's vector of active sensing. The governing radiative transfer equations for passive remote sensing of dense media are then derived by reference to the corresponding radiative wave equations for active sensing. The radiative wave equations are based on quasicrystalline approximation with coherent potential for the first moment of the field and a modified ladder approximation for the second moment of the field. The numerical results for classical radiative transfer theory and the dense media transfer theory are compared. The theory is also used to compare with brightness temperature measurements over a snow field.