Three-Dimensional Imaging Based on Beat Frequency Interferometry Using Sub-Band Decomposition for THz Radars

We propose a novel three-dimensional imaging method based on beat-frequency interferometry (BFI) using the sub-bands decomposition (SBD). This method effectively alleviates the severe phase ambiguity issue and reduces the measurement bias to improve the adaptability to steep terrains for THz radars. The simulation and proof-of-concept experiments demonstrate that, even under high electrical height conditions, the relative elevation accuracy can be maintained at the millimeter level. Compared to traditional interferometric synthetic aperture radar (InSAR), SBD-BFI provides an accuracy improvement by an order of magnitude.