布里渊分布式传感的空间分辨率及标定方法

针对基于布里渊散射原理的分布式光纤传感技术的重要参数之一——空间分辨率,通过分析定荷拉伸试验的结果,对比2种不同空间分辨率下实测的定点拉伸光纤的应变分布,说明了空间分辨率对测量结果的影响,探讨标定空间分辨率的10%~90%温度台阶法和温度热点法及其适用性.提出异种光纤串法,即将2种不同峰值频率的光纤、按不同长度交替熔接而成的光纤串,通过分析光纤串的测量结果对空间分辨率进行标定.试验表明,与温度台阶法和温度热点法相比,异种光纤串法具有准确、客观、测试结果的可对比性强等特点.

Spatial resolution and its calibration method for Brillouin scattering based distributed sensors

Spatial resolution is one of the important parameters for Brillouin scattering based distributed optical fiber sensing. The results of constant tensile load test were analyzed, and the strain distributions of point-by-point fixed fiber measured by two different spatial resolution respectively were compared. Then the influence of spatial resolution on measured strain was analyzed. Two spatial resolution calibration methods, including 10%~90% step-function method and hot-spot method, and their applicability were discussed. The dissimilar-fiber-splicing method was proposed to calibrate the spatial resolution. Dissimilar-fiber-splicing means two variant peak frequency fibers are alternately spliced in series with segments of different length. The calibration experiment shows that dissimilar-fiber-splicing method is accurate, objective, and comparative．