Thermal emission from a layered medium bounded by a slightly rough interface

The small perturbation method (SPM) is applied to study thermal emission fr om a layered medium bounded by a slightly rough interface, Brightness tempe ratures are calculated to second order in surface height, including both sp ecular reflection coefficient corrections and incoherent Bragg scatter term s. Unlike the homogeneous medium case, in which the SPM applied for emissio n predictions produces an expansion in surface slope, the theory remains a small height expansion, and convergence of the series is shown to depend on properties of the layered medium. Results from this theory can be applied in studies of soil moisture, sea ice, or sea surface remote sensing and bur ied object detection with microwave radiometers.