Create a matrix for data with various iterations

hey to all, thanks for reading this in advance. I want to calculate Surveillance_SignalFD and Reference_SignalFD as a matrix, where each rows corresponds to a different y_transmitter. The code I have, for each y_transmitter it calculates this variables, but on the next iteration it replaces the values of the previous one. I want to save all the values of each iteration in a matrix.

Thanks guys

for i=1:numel(waypoints)
    Y_transmitter = waypoints(i);
    for xx=1:200
        for yy=1:200
            if AoI(xx,yy) ~= 0 % Target detection
                X_target= xx;
                Y_target= yy;
                Surveillance_SignalFD=(1/(R1+R2))*X_QPSK.*exp(-1*j*k0*(R1+R2)); % Surveillance Signal frequency domain
                Reference_SignalFD=(1/Rd)*X_QPSK.*exp(-1*j*k0*Rd); % Reference Signal frequency domain