inp_GPRmodel1.m

function [ model1 ] = inp_GPRmodel1( )
% INP_GPRMODEL1 - Most importatnt one
%sets up model parameters for 2D Ground Penetrating Radar (GPR)
%  Full-Waveform Inversion (FWI). 
% Define model parameters for 2D GPR FDFD FWI
% 
% --------------------------------------------------------
%  Copyright @ Mrinal Kanti Layek (MKL)
%   Senior Research Fellow (Geophysics),
%   Department of Geology and Geophysics,
%   Indian Institute of Technology Kharagpur, 
%   Kharagpur - 721302, India
%   https://www.researchgate.net/profile/Mrinal_Layek
%   14.01.2018 (DD.MM.YYYY)
% -------------------------------------------------------
% On 14 th jan, 2018

path(path, eval('pwd'));
path(path, [eval('pwd') '/forward']);
path(path, [eval('pwd') '/input']);
path(path,[eval('pwd') '/output'])
path(path,[eval('pwd') '/outputmyINV'])
% path(path, [eval('pwd') '/inp']);
path(path, [eval('pwd') '/inv']);
path(path, [eval('pwd') '/obs']);

% 

%==========================================================================
%==================== Forward Model parameters ============================
%==========================================================================
  
% ------------------------2D grid parameters-------------------------------

% number of gridpoint in x- and y-direction

    model1.nx =180;
    model1.ny = 180;
        % spatial sampling interval [m]
    model1.dh = 0.05;
    model1.n = model1.nx * model1.ny;

    % define x- and y-axis [m]
    model1.x = model1.dh.*(1:model1.nx);
    model1.y = model1.dh.*(1:model1.ny);
% ------------------------------------:-------------------------------------   
    % define modeling input parameters
    model1.f = 50e6; % frequency 
    % model1.s = 0.0;
    model1.nfreq=10;
%     model1.omega = 2.0*pi*(model1.f+1i*model1.s);
%     model1.omega = 2.0*pi*model1.f;
    model1.mu0 = 4.0*pi*1e-7;  
    
    model1.eps01=1;
    model1.epsr=4.0;
    model1.m=2.0;
    model1.m1 = 2.0;
    % define thickness of PML boundary frame [gridpoints]  <<<<<<<---------
    model1.npml = 10;
    model1.a0_pml = 9e8;
       model1.a0_rot9p=1.79;
    % ^^^^^^^^^^^^^^^^^^^^^^^^^^^ CFS-PML parameters ^^^^^^^^
    model1.a0_cfs = 9e8;
    model1.kappax_max=5.0;
     model1.kappay_max=5.0;
    model1.alphax_max=0.2;
    model1.alphay_max=(pi./16.0).*1e8;
    
    % ^^^^^^^^^^^^^^^^^^^^^^^^^^^ -:- ^^^^^^^^
    % define free surface
    model1.free = 0;% Always keep 0 - It's tested by me
    
    % basename of input model
    
%     model1.file_true1 = 'input/CHPDX24.eps';
    model1.file_true1 = 'input/2_cross_TE_true.eps';
    model1.file_init = 'input/2_cross_TE_init.eps';
    model1.file_true2 = 'input/2_cross_TE_true.sig';
    % file names for source and receiver file
    model1.file_rec = 'input/receiver_2_cross_TE_p';
    model1.file_src = 'input/source_2_cross_TE_p';
    
   
    % define Caxis clip - Set colormap limits
%     c=gray;
%     model1.c=flipud(c);
    model1.caxis1 = 10;
    model1.caxis2 = 1;   
    % define fonts
    model1.FSize = 12;
    model1.Fweight = 'normal';
    
    % define figure size;
    model1.screenx = 1000;
    model1.screeny = 1000;
    
 
 %==========================================================================
% TD shot gather
%==========================================================================
model1.clip=2.5e-3; % clip data Blackman-Harris 
model1.clip1=1e-2;
model1.FC_low=50e6;
model1.FC_high=200e6;
model1.nf=50; %<<<<<<<<<<<<<<<<<<<<-----------------------------------||||
model1.df=(model1.FC_high-model1.FC_low)./(model1.nf-1);

%================ TD Parameters====================
model1.TmaxTD=150e-9; %Maximum recording time
% model1.dt = 
model1.sig_max=9e8;%following Chen et al. 2013
% model1.sig_max=(model1.m+1)./(150.*pi.*model1.dh.*sqrt(model1.epsr));
% model1.sig_max=4.0./(377.0.*model1.dh);% 0.1516

%==========================================================================
%==================== Inverse Model parameters ============================
%==========================================================================
%The radius of the taper is defined in meter by SRTRADIUS. 
% Note, that this radius must be at least 6 gridpoints    
model1.SRTRADIUS=80.0; %radius_in_m
%normalisation factor
model1.eps0=8.85e-12;
model1.sig0=5.6e-3;

% SELECT Upper & Lower limits of eps and sig

model1.sigr_low = 0.08e-3;
model1.sigr_high = 20.2e-3;

model1.epsr_low=3.8*model1.eps0;
model1.epsr_high=33.20*model1.eps0;

model1.beta_sig1=1.0;
model1.beta_eps1=1.0;

model1.beta_sig=1.0;% 1.0 in Germaine
model1.beta_eps=1.0;

model1.LAMBDA_1=0.0002;%1.0e-4
model1.LAMBDA_2=0.000;

% Damping gradient in PML with taper (for cp_grad_frame_TE)
model1.damp =60.0;
% #$$$$$$$$$$$$$$$$ GQN Method:LBFGS parameters $$$$$$$$$$$$$$$$$$$$#
model1.nlbfgs=5.0;
model1.lbfgs_pointer =1;
model1.nlbfgs_class=2.0;
model1.nlbfgs_vec=model1.nlbfgs_class.*model1.nx.*model1.ny;
% model1.beta_lbfgs=2.0;
model1.EPS_HESS=0.01;
model1.SIG_HESS=0.01;
% #$$$$$$$$$$$$$$$$$$$  Step length estimation $$$$$$$$$$$$$$$$$$$$$$$$#
model1.eps_scale = 0.01; 
model1.sig_scale = 0.01; 
% parameters_for_Wolfe_conditions_
model1.C1=1e-4;
model1.C2 = 0.9;
% maximum_number_of_attemps_to_find_a_step_length
model1.STEPMAX = 3.0;
model1.SCALEFAC = 2.0;
%
model1.cx1=0;
model1.cxe1=10;
model1.cxs1=10;
% Choices ------------------ Very Important --------------------------
model1.wolfe=1;%1- Run wolfe; 2- ALPHA_OLD =1.0;
model1.taper=2;
model1.damping=2;
model1.ACQMY=1;% 1= read Acquistion geometry for 4-sided configuration
model1.STAG=2; %1= regular staggered; 2= new staggered -developed by MKL
end