ACTIVE HIGH-RESOLUTION MULTIPLE-TARGET DIRECTION FINDING.

The problem of high-resolution direction finding is investigated specifically for active systems. The objectives are to improve the estimation performance and to reduce the implementation complexity of a direction-finding system by incorporating the waveform information available in an active system. Models for the array outputs of an active direction-finding system are formulated based on the waveform information of the transmitted signals. Two methods, the active-channel-efficient (ACE) method and the focus-and-add (FAA) method, are proposed. Both of them are shown to perform better than the direct application of the existing methods developed for passive systems. The ACE method is capable of using fewer coherent receiver channels than required by the existing methods. The results of computer simulations are included to demonstrate the capability of these two methods.