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 is one of the important parameters for Brillouin scattering based distributed op- tical 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 dif- ferent length. The calibration experiment shows that dissimilar-fiber-splicing method is accurate, objec- tive, and comparative.