12.1 INTRODUCTION

The ability to recognize targets quickly, at long ranges, and under all weather conditions has the potential to greatly enhance the effectiveness of AEW systems. This chapter provides a discussion of the fundamentals of target recognition technology and concepts. Emphasis is placed on recognition techniques as applied to radar signatures, for the AEW system's radar(s) will in general provide the most reliable, long-range, all-weather, all-scenario data upon which to base the recognition process.

It is likely that incorporation of effective radar-based target recognition techniques will require either modifications in the AEW's primary radar or its surveillance requirements, or the inclusion of an ancillary radar that is at least partially dedicated to the recognition function. In particular, recognition will require higher signal-to-noise-ratios (SNRs) than those needed for detection and, depending on the techniques utilized, it will also require long target dwells and/or high system bandwidths. Since it is unlikely that surveillance requirements will be sacrificed, one must assume either an enhanced primary radar that includes phased-array operation or addition of an adjunct radar system. Note that assuming a phased-array primary AEW radar seems eminently reasonable in light of the fact that both Israel and Sweden have phased-array AEW radars under development, as indicated in Section 10.3, and, as indicated in Section 1.3.4, general detection and tracking performance benefit from such a configuration.

In Section 12.5, Fusion For Recognition, the other AEW sensors such as identification, friend or foe