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| function tt = filter_SSH(data,lon_size,lat_size)
%filter SSH data
m=mean(data(:));
ee = data - m; %remove mean
dd = fft2(ee); %fft 2D
ii = fftshift(dd.*conj(dd));
uu = fftshift(dd);
s=size(ii);
hh = zeros(s(1),s(2));
for i=1:s(1)
for j=1:s(2)
if (i-s(1)/2)^2/lon_size+(j-s(2)/2)^2/lat_size < 1 %remove all the low frequency
hh(i,j)=uu(i,j);
ii(i,j)=0;
% uu(i,j)=0;
end
end
end
% figure
% surface(1:s(2),1:s(1),hh)
% hold on
% plot(s(2)/2,s(1)/2,'kx')
D=hh;
% figure
tt = ifft2(ifftshift(D),'symmetric'); |
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