Computer simulation of the use of Barker phase codes for the detection of overlapping targets in clutter

The time extents of pulse compression (spread-spectrum) signals are often so long that the signals may overlap, for example the case of radar targets that are close together. The effect of this overlapping is considered in a general versatile computer simulation for the cases of steady strong and weak signals in a Weibull clutter environment. The signal reported in the paper is a 39-bit combined Barker word which when compressed in a 150-bit transversal filter of the minimum square error type will give -40 dB temporal sidelobes. The results demonstrate quantitatively that, in the case of identical radial velocities, signal overlap is strongly detrimental to signal detection. Typically, if there are two signals (one strong and the other weaker) in a clutter environment then, if the uncompressed weak signal/clutter ratio is -3 dB and if the strong-signal/ weak-signal ratio is 9 dB, both signals may be detected until there is an overlap of about 50 percent. At greater overlap the compressed weak signal cannot be identified in the clutter.