Scanning limitation in adaptive superresolution array

A fundamental limitation in an adaptive superresolution array, due to reciprocity between the angular resolution capability and the measurement time required, is discussed. For this purpose, a new concept for the measurement time, a scanning time concept, is introduced by considering a superresolution array consisting of an Applebaum-Howells adaptive processor with steering signal changing periodically with time. The measurement time is defined as the amount of time taken to perform one observation over the range of desired angle. Superresolution array output is defined according to the adapted angular response formulation. It is shown that the relationship between the resolution capability and the scanning time is reciprocal, i.e., the increased angular resolution is obtained at the expense of the scanning time. The relationship is discussed quantitatively for a narrow-band signal model.