Robustness of joint transform correlator versus VanderLugt correlator

The robustness of the joint transform correlator (JTC) versus the VanderLugt correlator (VLC) are evaluated based on the transversal and the longitudinal misalignment. We show that the VLC is very sensitive to the transversal misalignment, while the JTC is not. Although the VLC performs better in terms of longitudinal alignment, the tolerable misalignment in recording the joint transform power spectrum (JTPS) is in the order of a millimeter, which can be easily adjusted in practice. In short, we conclude that the JTC is far more robust than the VLC. (C) 1997 Society of Photo-Optical Instrumentation Engineers.