A preliminary investigation has made of external noise resulting from the finite target size in tracking radar range information using the PB4Y and SNB aircraft as targets. The power spectrum and amplitude distribution function of recorded external range noise is given for each view of these aircraft. The total rms external range noise is shown to be a function target shape and size. A formula was developed which related target configuration to the total rms external range noise, and which allows the prediction of the rms noise for a given target. Future plans include making a complete study of the external range noise problem using various range error detection techniques.