The main script for SAR image modelling with the GG-Rician distribution.

The GG-Rician probability density function for modeling an amplitude signal is given below [1]

$$f(r|\alpha, \gamma, \delta) = \frac{\alpha^2 r}{4\gamma^2\Gamma^2(\frac{1}{\alpha})}\times\\ \int_0^{2\pi} \exp\left(-\frac{|r\cos\theta - \delta|^{\alpha} + |r\sin\theta - \delta|^{\alpha}}{\gamma^{\alpha}} \right) d\theta,$$

The GG-Rician probability density function for modeling an intensity signal is given below [1]

$$f_I(\nu|\alpha, \gamma, \delta) = \frac{\alpha^2 }{8\gamma^2\Gamma^2(\frac{1}{\alpha})}\times \int_0^{2\pi} \exp\left(-\frac{|\sqrt{\nu}\cos\theta - \delta|^{\alpha} + |\sqrt{\nu}\sin\theta - \delta|^{\alpha}}{\gamma^{\alpha}} \right) d\theta. $$

The main function uses three main global structure type variables. All of which has various elements. All details are given below.

Parameters : GLOBAL VARIABLE. A structure type variable which stores various parameters given below:

Output : GLOBAL VARIABLE. A structure type variable which stores various output variables given below:

Results : GLOBAL VARIABLE. A structure type variable which stores variables given below:

alpha : Instantenous proposal for the shape parameter.

gamma : Instantenous proposal for the scale parameter.

delta : Instantenous proposal for the location parameter.

file, path, prompt, dlgtitle, dims, definput, answer, opts : These are variables for pup-up dialog box. When user choses distType = 3, or ourSourceImage = 1, a specific dialog box pops-up and asks user to enter corresponding parameters.

For the functions dsSARImage(.), logLikelihoodCalculation(.), instantenousPlotting(.), and performancePlotting(.), please visit specific function's .m file.

LICENSE

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/.

Copyright © Oktay Karakus,PhD o.karakus@bristol.ac.uk University of Bristol, UK June, 2020

REFERENCE

[1] O Karakus, E Kuruoglu and A Achim. "A Generalized Gaussian Extension to the Rician Distribution for SAR Image Modeling." IEEE Transactions on Geoscience and Remote Sensing (2021).

[2] O Karakus, E Kuruoglu and A Achim. "Modelling Sea Clutter In SAR Images Using Laplace-Rician Distribution," ICASSP 2020 - 2020 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Barcelona, Spain, 2020, pp. 1454-1458."