APPLICATION OF HADAMARD-TRANSFORM TO FIBEROPTIC SMART-SKIN SENSING

An array of optical fibers can be applied to smart-skin sensing applic ations, which include stress monitoring, fatigue detection, temperatur e sensing, etc. Although a single light source can be used in a fiber array sensor, the input light power is divided by a sensing fiber arra y and each fiber may require a detector. Thus as the channel number of a fiber array increases, the number of detectors also increases and t he signal intensity of each fiber channel decreases, which decreases t he signal-to-noise ratio and increases the complexity and the cost of the system. In this article we will analyze the Hadamard transform to enhance the signal processing of the fiber array sensor. The apparent advantages are that only one detector is needed and the signal-to-nois e ratio of the fiber array sensor can be improved by a factor of squar e-root N/2, where N is the number of sensing fibers. Analysis for an a rray of 127 sensing fibers is illustrated, in which we have shown that the calculated results are in agreement with the analytical model. (C ) 1993 John Wiley & Sons, Inc.