Abstract: BIBASS, abbreviated from the Bistatic Interferometer BAsed on Spaceborne SAR (BIBASS), using the existing spaceborne SAR systems as transmitters of opportunity, is an air-based or a ground-based multi-channels receiver for interferometric application. In this paper, the advantages as well as some research progress of BIBASS is overviewed firstly, and the principle of height measurement for BIBASS is analyzed. Then, BIBASS configuration, at system level, is presented，and some system parameters, such as Signal-to-Noise Ratio (SNR), 2-D resolution, relative height accuracy, of BIBASS are analyzed. At last, based on TerraSAR-X as the transmitter of opportunity, the de-cohenrence and relative height error of BIBASS are simulated and evaluated for a large scenery. It can be seen from the discussion in the paper that BIBASS is an innovative bistatic interferometric system with the advantages of simplicity, low-cost, high-resolution and high-height-accuracy for a large-scaled scene, and will be widely used in terrain survey in the future.