Systems Engineering and Electronics ›› 2021, Vol. 43 ›› Issue (7): 1781-1790.doi: 10.12305/j.issn.1001-506X.2021.07.07

• Radar sparse signal processing technology • Previous Articles     Next Articles

Sparse SAR imaging based on varying prior Bayes learning

Xiaoyun SHEN, Xianhua LIAO, Weitian SUN, Yabo XIA, Lei YANG*   

  1. 1. College of Electronic Information and Automation, Civil Aviation University of China, Tianjin 300300, China
    2. Tianjin Key Laboratory for Advanced Signal Processing, Civil Aviation University of China, Tianjin 300300, China
  • Received:2020-12-30 Online:2021-06-30 Published:2021-07-08
  • Contact: Lei YANG

Abstract:

Aiming at the problem of prior solidification and over-fitting imaging results easily of traditional Bayesian learning imaging algorithms in sparse synthetic aperture radar (SAR) imagery, a varying imaging prior Bayes (VIP-Bayes) learning algorithm is proposed. Firstly, the generalized Gaussian distribution variable dynamic prior is introduced, which can realize the dynamic and flexible representation of the target scattering prior knowledge. Then, in the framework of Bayesian inference, a hierarchical Bayesian model is introduced to derive the posterior distribution. Finally, aiming at the problerm, which the conventional Gibbs algorithm cannot sample the obtained complicated posterior distribution, the Hamiltonian Monte Carlo (HMC) sampling algorithm is introduced to solve the problem. In addition, considering the HMC algorithm can't sample for non-smooth posterior distributions. This paper introduces a proximal operator to approximate the gradient, and obtains the proximal-HMC (P-HMC) sampling algorithm. P-HMC algorithm can effectively solve the problem of non-smooth posterior sampling, for this reason, it can realize sparse imaging based on VIP-Bayes learning. The effectiveness of the algorithm is verified by using the simulation data, then select SAR raw data to conduct a variety of algorithm imaging comparison experiments. Finally, phase transition diagram is applied to quantitatively analyze the algorithm imaging performance. In a word, all above experiments verifies the practicability and superiority of the proposed algorithm.

Key words: synthetic aperture radar (SAR), Bayes learning, Hamiltonian Monte Carlo (HMC) algorithm, generalized Gaussian distribution (GGD)

CLC Number: 

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