Study of White-Light Optical Image Subtraction for Possible Application to Missile Tracking and Identification

摘要

In this study, the coherence requirement for an incoherent image subtraction processor is analyzed, with the partial coherence theory of Wolf. We have shown that image subtraction operation is basically a 1-D processing operation and the spatial coherence requirement is a point pair concept. A source encoding mask can be utilized to alleviate the constraint of a physical light source, such that the image subtraction can be carried out with extended incoherent source. We have also in this study demonstrated the possibility of utilizing the image subtraction technique as applied to micro-circuit board inspection, which would have a profound effect on precision inspection scheme for large scale automatic assembly for U.S. Army needs and her supporting industries. This technique would provide the capability of rapid identification inspection, and possibly utilizing for synthesis and fabrication. The effects due to coherence requirement are also included. Experimental simulations of the IC chip inspection are provided.