A Position-First 3D Inversion Method for Tomosar

Three-dimensional imaging with tomographic SAR is a hot research topic in the field of SAR. The existing methods usually solve the question based on elevation discretization. When the target point has an off-grid deviation, the accuracy will decrease and the number of spurious points will increase. In this paper, a position-first step-by-step 3D inversion method is proposed. By constructing the observation equation with only an unknown elevation position, the height of the scattering center is directly solved in the continuous domain based on the least square criterion, and then the scattering coefficient is calculated based on the position. Simulation results verify the effectiveness of the method compared with the classical OMP algorithm. The proposed method has higher estimation accuracy under the same noise level and observation number and is less affected by the scattering center spacing.