The interpolated ESPRIT algorithm for direction finding

The technique of interpolated arrays is applied to ESPRIT-type direction finding methods. The resulting method uses sensor arrays with arbitrary configuration, thus eliminating the basic restrictive requirement of ESPRIT for two (or more) identical arrays. It is shown that while ESPRIT performs poorly for signals propagated in parallel (or close to parallel) with the array displacement vector, the advocated technique does not exhibit such weakness. Using two subarrays ESPRIT cannot resolve azimuth and elevation even when the sensors are not collinear. However, the interpolated ESPRIT procedure resolves azimuth and elevation using only a single array. All the mentioned advantages are obtained with a reasonable increase of computation load. The authors also discuss, and illustrate numerically, the performance of the original ESPRIT when the sensor locations are perturbed