脉冲相位光热辐射测量中的数据拟合处理方法

Data Fitting Method in Pulsed Phase Thermography

针对脉冲相位辐射测量中相位分析对时间信号噪声比较敏感的问题,对实验得到的温度-时间数据进行拟合处理。计算结果表明,对数据进行分段拟合(分别采用线性拟合和指数曲线拟合)能得到比较理想的近似函数。傅里叶变换后得到的相频曲线噪声小,相位图像较清晰。并且数据可用拟合函数的系数来表示,从而大大减少数据存储量。另外,通过曲线扩展和插值的方法,从理论上分析了采样频率与窗口长度对相频特性曲线的影响。

Since the phase was sensitive to noise in pulsed phase thermography technique,the data of temperature obtained from the thermal wave experiment was fitted in order to reduce the noise influence.The fitting result indicated that piecewise fitting could get better fitting functions,consequently could get phase curves with low noise and a clear phase image after Fourier transform.Another advantage was that data could be represented by coefficients of fitting functions,and the storage of data could be greatly reduced.The effect of the value of sampling frequency and window width on phase through fitting was analyzed by using interpolation methods.