Dual-Frequency Distributed Compressive Sensing TomoSAR Method for Reducing Flight Requirements

The existing single-frequency tomographic synthetic aperture radar (TomoSAR) 3-D reconstruction method suffers from insufficient observation information due to the high cost and long period of acquisition of the required multi pass data. To effectively alleviate these problems, it is a feasible solution that a sensor carries dual-frequency radars that can work simultaneously and acquire dual-frequency data for 3-D imaging. This letter systematically introduces the theory and model of dual-frequency TomoSAR 3-D imaging system, and proposes a dual-frequency distributed compressive sensing (DF-DCS) TomoSAR method for reducing flight requirements. First, this method combines the neighborhood pixel information to effectively improve the signal-to-noise ratio (SNR). Then, the reflectivity profiles of the dual-frequency data are jointed to increase the unambiguous height and the accuracy of the target position estimation. Finally, the point-target simulation experiments and surface-target experiments based on SAR simulation (SARSIM) system verify the effectiveness of the proposed method. With the reconstruction accuracy maintained, the DF-DCS method can effectively improve the ability to resolve ambiguity and reduce the required flights.