Abstract

Many different aperture configurations for phased telescope arrays have been advocated during recent years, each with its own rationale. Several of these proposals are reviewed and their relative merits discussed for various imaging applications. If a phased telescope array is to produce satisfactory images of extended objects containing a wide range of spatial detail, the modulation transfer function (MTF) that results from the subaperture configuration must approximate that obtained by a clear circular aperture whose diameter is equal to the maximum dimension spanned by the subapertures. In particular, the MTF must contain no regions of zero value, since image detail is irretrievably lost in those regions. A family of 2-D nonredundant subaperture arrays¹ is reviewed and their properties dramatically compared to other configurations by a series of photographs of a spoke target containing a continuous range of spatial frequencies at all orientations. The experiment was carefully designed to demonstrate the ability of redundant and nonredundant arrays of various dilution ratios (fill factors) to resolve detail. The effects of image noise on the success of image restoration techniques are also reviewed.

© 1986 Optical Society of America