In a ground penetrating radar system, A-scan images of subsurface targets lying along the antenna boresight axis can be substantially improved and generated in real-time by employing a synthetic aperture, end-fire array, despite the inhomogeneous nature of the subsurface volume. The synthetic aperture, end-fire array is achieved by generating electro-magnetic (EM) ultra-wideband impulses at a number of precise locations along the antenna boresight access, shifting the returned EM signals in the time domain according to the corresponding antenna boresight location, and then integrating the shifted, returned EM signals.