[57] A method of radar signal processing to detect a target object, the method comprising the steps of: transmitting radar signals from a radar system, the radar signals being transmitted according to a predetermined frequency scheme and also including frequencies of return signals comprising portions of the radar signal echoed from the target object, wherein the frequencies of the return signals comprising portions of the radar signal echoed from the target object, wherein the frequencies of the return signals may be frequency shifted from the predetermined frequency scheme by unknown amounts; coherently integrating the received signals to transform time domain data of the received signals into frequency domain templates of data; arranging the frequency domain templates of data; arranging the frequency domain templates into an array matrix; processing at least a portion of the frequency domain templates to form presums; storing the presums required for use in forming higher level presums or acceleration bins; forming acceleration bins from the presums; and analyzing the acceleration bins to detect the presence of a return signal from the target object.