%		GENTTF02.M

PRI=T2; 			% PRI pulse repetition interval
N=1;;			% number of samples
ts=PRI*pulses;

% load gentra02
% 
%-----+BEGIN+------------------------------------------
%
%
% get every 64th sample value
%
%t1=Sik(1:pulses);
Sik_long=64*256;
t2=Sik(1:pulses:Sik_long);
%t3=1:pulses;
tb=t2;
gtb=t2;

%
% Try to compute the initial frequency fp in Gabor functions
% from the range cells. It can be set manually so that
% final images appear centered
% 

% Get first and last cross-range information

vec = th_256(:,1);
vecf = fft(vec);
%vecf2 = vecf(1:(length(vecf)/2));
vecf = fftshift(vecf);
frecu = -0.5:(1/length(vecf)):0.5;
frecu = frecu*(1/ts);
frecu(length(frecu))=[];
figure
subplot(211)
vecf2 = abs(vecf);
plot(frecu,vecf2)
tres = max(vecf2)/4;
fpf = find(vecf2>tres);
fpf1 = fpf(1);
fpf2 = fpf(length(fpf));
fp = (frecu(fpf1)+frecu(fpf2))/2;
fp = -fp;

if abs( frecu(fpf1)-frecu(fpf2)) > frecu(length(frecu))*0.75
   fp = frecu(length(frecu));
end

title(['FFT of first range cell. fp at = ',num2str(fp)])

% Set fp here manually if an undesired image (uncentered target) results
% at the end of the program
%
% fp = ;

clear vec vecf fpf fpf1 fpf2

vec = th_256(:,21);
vecf = fft(vec);
%vecf2 = vecf(1:(length(vecf)/2));
vecf = fftshift(vecf);
subplot(212)
vecf2 = abs(vecf);
plot(frecu,vecf2)
title('FFT of middle burst.')

clear vec vecf frecu vecf2 

%
% Generate 64 samples of Gabor function using Sik the same sample times as 
% the signal, this is the same timebase as a range profile. 
%
%-------------------------G0_256----------------------------%
% n=8;
ap=(n*ts)^2;
fpo=fp;			% max frequency 
tn=65;    		% increments n between g matrices
tp=((tn-1)*ts)/2;	% Regular Gaussian window center.
tp1=tp;
%
for i=1:64		
   %fp_vctr1(i)=fp;
   fn=1/sqrt(2*pi*ap);			% normalizing term
   fn1=exp(-((gtb-tp).^2)/(2*ap));	% Gaussian window term
   fn2=exp((j*2*pi*fpo*(tb-tp))/N);
   gabor(i,1:burst)=fn*fn1.*fn2;
   fpo=fpo+1/(pulses*ts);
end;
g0_256=gabor;
%-------------------G1_256-----------------------------
% n=8;
ap=(n*ts)^2;
fpo=fp;			% max frequency 
tn=193;    		% tp=1 sec ,T=3.025 sec
tp=((tn-1)*ts)/2;	% Regular Gaussian window center.
tp2=tp;
%
for i=1:pulses		
   %fp_vctr1(i)=fp;
   fn=1/sqrt(2*pi*ap);			% normalizing term
   fn1=exp(-((gtb-tp).^2)/(2*ap));	% Gaussian window term
   fn2=exp((j*2*pi*fpo*(tb-tp))/N);
   gabor(i,1:burst)=fn*fn1.*fn2;
   fpo=fpo+1/(pulses*ts);
end;
g1_256=gabor;
%%%-----------------------G2_256---------------------------------------%%%
% n=8;
ap=(n*ts)^2;
fpo=fp;			% max frequency 
tn=320;    		% tp=2 sec, T=3.0025sec
tp=((tn-1)*ts)/2;	% Regular Gaussian window center.
tp3=tp;
%
for i=1:pulses		
   %fp_vctr1(i)=fp;
   fn=1/sqrt(2*pi*ap);			% normalizing term
   fn1=exp(-((gtb-tp).^2)/(2*ap));	% Gaussian window term
   fn2=exp((j*2*pi*fpo*(tb-tp))/N);
   gabor(i,1:burst)=fn*fn1.*fn2;
   fpo=fpo+1/(pulses*ts);
end;
g2_256=gabor;
%%%-------------------------G3_256------------------------------------------%%%
% n=8;
ap=(n*ts)^2;
fpo=fp;
tn=449;			% tp=   sec, T= 3.025
tp=((tn-1)*ts)/2;
tp4=tp;
for i=1:pulses
   %fp_vctr2(i)=fp;
   fn=(1/sqrt(2*pi*ap));		% normalizing term
   fn1=exp(-((gtb-tp).^2)/(2*ap));	% Gaussian window term
   fn2=exp((j*2*pi*fpo*(tb-tp))/N);
   gabor(i,1:burst)=fn*fn1.*fn2;
   fpo=fpo+1/(pulses*ts);
end
g3_256=gabor;
%-------------------------------------------------------------------%
%
wtv02img
%
%		END OF GENTTF02.M