a system for detecting the presence of clutter utilizing an area overlap technique that effectively rejects scintillating position clutter near the boundaries of the area clutter map acm cells . a first area clutter - mapper system is provided with its area acm cells at a first position and a second clutter - mapper system is provided with its acm cells in a second position with each cell displaced by about one - half acm cell dimension in range and azimuth to overlap the original acm cell boundaries . all of the clutter returns which were divided among the original set of acm cells occur in one of the area overlap acm cells so that when the clutter scintillates between acm cells for any selected detection criterion , it is identified as clutter rather than a moving target . separate detection history counts for clutter - identification and inhibit code for clutter rejection are provided in both the first and second clutter overlap map units . a clutter rejection code or condition in either area map unit will determine that clutter is present and the control gate samples either the clutter amplitude or a cluster code in both the first and second acm cell units and rejects target signals if clutter has been determined in either of the units . in one modeling of the concept of invention , it was found that the area overlap method increased the amount of clutter rejected by 55 % over a conventional single acm mapping system unit .