Synthetic-aperture optical array imaging system: selection of array data for single-point focusing

In a previous article by the author (ICASSP 1991 p.2613-16), a synthetic-aperture array imaging method was presented. The method first collects array data by illuminating the object with laser light sequentially at each of a number of angles and by detecting the reflected field with an array sensor. Then, on a computer, the eigenvector with the largest eigenvalue for the correlation of the array data is derived, and a beam steering operation is applied to the eigenvector to reconstruct the object. The eigenvector, however, does not always backpropagate to focus at a single point on the object, when it has several parts with similar reflectivities, resulting in blurred reconstructed images. The array data are selected based on the aperture region to improve the focusing characteristic, where two criteria measuring the single-point focusing are used. Basic experimental results are given