The problem is that you overwrite your value of data each time the inner loop is executed.
If you just want to plot each image and not do anything else with it, you could move your line that plots the data inside of the loop and make a new figure for each plot, so something like this:
for k = 1:clutternumber
clutter_x = xa1(k);
clutter_y = ya1(k);
clutter_location = [clutter_x clutter_y ];
for i = 1:1:1024
target_location = ...........
radar_location = ............
conv_target = ..
conv_clutter = ..
sum = conv_target + conv_clutter;
data(i,:) = sum;
end
% plot the image
figure
imagesc(real(abs(data)), 'XData', [range]), colormap turbo;
end
If you want to do more with the data, then you will need to save it, for example in an array with three dimensions, the first dimension could be the clutternumber, and the other two would provide the image, or you could make a cell array of images
