We propose a novel high efficiency holographic memory system for three-dimensional (3D) rotation invariant automatic target recognition. The proposed system combines the state-of-the-art photorefractive crystal holographic memory, distortion invariant filter design, and error correction coding technique. More than a hundred 3D rotation invariant composite bipolar filters will be recorded in the crystal and can be accessed in parallel. A high diffraction efficiency (>0.1 % for each recorded filter) can be achieved. A bit error rate less than 10(-6) will also be obtained by using our proposed error correction coding technique. In addition, the proposed holographic correlator will be light weight, compact, low power consumption, and easy to use. This project will result in a practical holographic correlator for both military and commercial applications.
