基于光纤马赫-曾德尔(M-Z)干涉技术对周界防范系统进行了研究设计。采用改进的双光纤M-Z干涉相位检测技术与互相关算法相结合的方案进行信号提取。详细介绍了互相关算法在系统定位方面的应用,并通过实验证实其可行性。对两路经过不同延时的相同信号进行互相关运算,通过峰值位置可准确得到延时时间差。系统的定位精度与采样频率有直接关系,在采样率为20MHz时,理论上的定位精度可达10.22m。提出了一种分段数据处理方法,该方法可以在保证高采样率带来的高定位精度的基础上降低算法的运算量。实验结果表明,运算速度比传统方法提高约8倍。
A fiber-optic perimeter security system based on Mach-Zehnder(M-Z) interferometer is designed.Modified phase detection of double-fiber M-Z interferometer is proposed in getting signal in combination with correlation algorithm.The usage of correlation algorithm in location is introduced in detail.The simulation verifies the feasibility of this method.If the same signals with different time delays are analyzed using correlation algorithm,the accurate time difference can be obtained by the location of the maximum.The system′s location accuracy is directly related to the sampling rate.When the sampling rate is set as 20 MHz,a theoretical location accuracy of 10.22 m is obtained.A new method of processing piecewise signal is presented,which can reduce the computational complexity on the base of high positioning accuracy brought by the high sampling rate.The computation speed is increased about 8 times.