A Generalized Gaussian Extension to the Rician Distribution for SAR Image Modeling

TL;DR

This paper introduces the GG-Rician distribution, a new statistical model for SAR images that improves modeling accuracy across various scenes and frequency bands, enhancing applications like target tracking and despeckling.

Contribution

The paper proposes the generalized-Gaussian-Rician distribution, extending the Rician model with generalized-Gaussian components for better SAR image characterization.

Findings

The GG-Rician model outperforms existing models like K, Weibull, Gamma, and Lognormal.

Statistical tests confirm the superior fit of the GG-Rician model across diverse scenes.

The model is applicable to both amplitude and intensity SAR images.

Abstract

In this paper, we present a novel statistical model, $\textit{the generalized-Gaussian-Rician}$ (GG-Rician) distribution, for the characterization of synthetic aperture radar (SAR) images. Since accurate statistical models lead to better results in applications such as target tracking, classification, or despeckling, characterizing SAR images of various scenes including urban, sea surface, or agricultural, is essential. The proposed statistical model is based on the Rician distribution to model the amplitude of a complex SAR signal, the in-phase and quadrature components of which are assumed to be generalized-Gaussian distributed. The proposed amplitude GG-Rician model is further extended to cover the intensity SAR signals. In the experimental analysis, the GG-Rician model is investigated for amplitude and intensity SAR images of various frequency bands and scenes in comparison to state-of-the-art statistical models that include $\mathcal{K}$, Weibull, Gamma, and Lognormal. In order to decide on the most suitable model, statistical significance analysis via Kullback-Leibler divergence and Kolmogorov-Smirnov statistics are performed. The results demonstrate the superior performance and flexibility of the proposed model for all frequency bands and scenes and its applicability on both amplitude and intensity SAR images. The Matlab package is available at https://github.com/oktaykarakus/GG-Rician-SAR-Image-Modelling.