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Subject: SAR polar formatting: using griddata
Date: Mon, 19 Jan 2009 23:46:02 +0000 (UTC)
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Hi everyone,

I am trying to polar format a phase history data set down to a rectangular grid to form an image.  The data set is complex valued, but I have read that shouldn't matter using griddata.  The data set is an 1800x1999 array.  I have attempted to compute the location of each sample in the frequency domain in polar coordinates, convert that to rectangular, and use griddata from there.  I am getting errors for OUT OF MEMORY, and errors using qhullmx as well.  here is my code as of now

%number of samples per pulse, 1800.  1999 pulses
rf = Beff*(double((0.0:1.0:nsamps-1))-nsamps/2)/nsamps + Bc;
thetaf = dtheta*double((0.0:1.0:npulses-1))/npulses+theta_1;

[thetaF,rF] = meshgrid(thetaf,rf);

[X,Y] = pol2cart(thetaF,rF);

XI = (0:10:1800);
YI = (0:10:1999)';
Z = phase_vector;
ZI = griddata(X,Y,Z,XI,YI,'nearest');

is there a problem with the arguments X,Y in griddata being matrices instead of row and column vectors?  the help file in matlab is not too helpful in describing the format the arguments need to be in.

Any help would be appreciated, thanks!

Joe