LINEAR IMAGING WITH SENSOR ARRAYS ON CONVEX POLYGONAL BOUNDARIES

The resolution of a linear imaging system is determined by the size of the aperture on which it measures data. For a fixed number of sensor elements, large two-dimensional (2-D) apertures are formed when the elements are placed on the boundary of some planar region. It is proven that it is possible, in principle, to use only the boundary of some convex region as the aperture, while synthesizing the effect of having placed sensors throughout the interior of that region. This allows sidelobe levels to be controlled. Such a possibility is clearly of interest to designers of large, distributed sensor arrays for use in both active, transmit/receive imaging and passive, receive-only imaging. The central idea that is exploited in the work is that of the coarray of an aperture. Signal processing techniques have been developed that effectively "fill-in" the missing elements from the interior of the aperture for the cases of rectangular, hexagonal, and triangular boundary apertures.