A Novel Phase Error Estimation Algorithm for Multi Phase Center Multi-Beam SAR System

The conventional orthogonal subspace (OS) phase error estimation algorithm is limited in its applicability when dealing with scenarios involving a small number of channels and unclear dimension settings for the signal space. Further more, this algorithm assumes an equal contribution of different frequency points to the cost function, which compromises its robustness. To address these challenges, this paper introduces an improved orthogonal subspace (IOS) phase error estimation algorithm based on an extended subspace projection multiplane wave (SP-M) reconstruction model, incorporating the principle of orthogonality between the signal subspace and noise subspace. The proposed algorithm is validated through rigorous processing of actual measurement data, demonstrating its efficacy and potentials.