正弦波拟合参数的不确定度评定

The Measurement Uncertainty of Curve-fit Parameters of Sinusoidal

介绍了用4参数正弦波最小二乘拟合法拟合参数不确定度分析和评价过程。讨论了主要的不确定度来源,包括信号源误差、采集序列谐波失真、采集序列噪声及非谐波失真、采集序列中信号周期抖动、软件拟合运算误差的影响等,给出了减小不确定度的主要措施。结合一个幅度拟合实例给出了评价结果。

It is described that the uncertainty of evaluation results of sine wave parameters by using the least mean square four-parameter sine wave curve-fit method, including the courses of analysis and evaluation of uncertainty of it. Some error sources of curve-fit parameters are discussed, including the signal amplitude errors, the harmonic distortion of sampling serials, the quantization errors ＆ noise ＆ the spurious distortion, the jitter of the signal periods in sampling serials, the calculation errors of software, and the others. The Uncertainty of curve-fit parameters is given out, and several main methods about decreasing the curve-fit parameter errors and evaluation uncertainty have been proposed. In an example of experiment, that the analysis and uncertainty evaluation results of amplitude of sine wave by using curve-fit method is presented.