A passive bistatic radar (PBR) system, which exploits the digital terrestrial television broadcasting (DTTB) emitter as the illumination source without using a dedicated transmitter, has been developed for subsurface target detection. Its main features are low system cost, high system flexibility, and no need for frequency allocation. In this paper, at first, the fundamental concept, system components, and basic signal processing methods are introduced. The characteristics of the adopted DTTB signal with the Japan ISDB-T standard are evaluated. Then, one of the key techniques for ISDB-T DTTB signal based PBR, i.e., reference signal refinement (reconstruction and modification), is presented to suppress the strong sidelobes in the range-Doppler domain caused by the waveform properties and multipath echoes. Preliminary experimental results are shown to demonstrate the basic functions of the developed radar system. It has been found that the reference signal refinement method can work well in practice and a metallic plate buried in the sand can be effectively detected by the developed PBR system. At last, potential improvement directions of the PBR system for subsurface target detection, e.g., combing multiple bands, working with cooperative targets, and using super-resolution algorithms, are provided.