Characteristic features of radar detection of the boundary between two dispersive media having minimum electrical contrast

Characteristic features of ultra wide band (UWB) radio pulses reflection from a flat boundary between two lossy media with minimum contrast of dielectric permittivities are examined. The task has a high-priority for radar probing of upper soil layer and is connected with ranging of boundary between two media with close electrical parameters. This problem was solved many times for quasi-coherent signals and for transparent media. It was analyzed in [1] for UWB signals and monostatic GPR when difference of touching media electrical properties was pronounced (including a case of continuous vary of electrical properties near of boundary). Here we restrict ourselves in sharp border of homogeneous media in order to determine a generality of UWB signals reflection from low-contrast boundaries.