Susumu KUWAMURA and Ichirou YAMAGUCHI

Institute of Physical and Chemical Research (RIKEN), 2-1, Hirosawa, Wako, Saitama, 351-01 Japan

(Received January 30, 1996; Accepted July 30, 1996)

We propose a simple optical approach for the convolutional pre-processing of stellar specklegrams in the shift-and-add (SAA) method. It uses an incoherent optical processing, where a speckle pattern on a displaying device is re-imaged and a point-spread-function of the re-imaging system is used as the convolution kernel. This approach is suitable for use in the real-time SAA-system recently proposed. Experimental results using observational stellar specklegrams displayed on a cathode-ray-tube-monitor are reported to demonstrate that the optical pre-processing improves the signal-to-noise ratio of the final image.

Key words : stellar speckle interferometry, shift-and-add method, convolutional pre-processing, incoherent optical processing