【摘要】 本文将超声回波模拟成被高斯白噪声污染的高斯回波,并建立关于一系列估计参数的非线性模型,如回波的频带宽度,到达时间,中心频率,相位及回波幅度。这些参数对于超声无损检测中材料检测、目标探测、目标分类、及速率测量等密切相关。运用高斯-牛顿算法进行迭代计算,该算法能以较少的迭代次数计算出较为精确的参数向量,但该算法对到达时间τ的初值设置较为敏感。更多还原

【Abstract】 The ultrasonic echo is modeled as the Gaussian echo that is corrupted with white Gaussian noise(WGN),and the nonlinear model on a series of estimated parameter as bandwidth,arrival time,center frequency,phase and echo amplitude is established. These parameters are closely related to the materials detection,target detection,object classification and velocity measurement in nondestructive evaluation.Gauss-Newton al- gorithm is applied in the iterative calculation,the algorithm can calculate the vector parameter with few iterative times,and yet the convergence of the algorithm is sensitive to the initial value of arrival timeτ.更多还原