超声检测中变采样问题研究

Variable sampling in ultrasonic testing

本文对超声检测中常遇到的变采样问题进行讨论,比较了两种实现方法:基于特征值的二次采样和滤波器组,并给出了二次采样算法。通过试验,对这两种方法在超声信号变采样前后时频域特性的变化做了比较分析,得出前者可以很好地保留检测中所需的特征信号,但频域特性较差;而后者有很好的频域特性,便于进行时频分析。

In the paper, we discuss the variable sampling in ultrasonic testing, and compare two techniques, i.e., the resampling arithmetic and the filter group. We analyze the RF signal's characteristics in time and frequency domain before and after processing with the two methods. Results show that the former reserves the characteristics of RF signal we need, but shows worse performance in the frequency domain; the later has better performance in the frequency domain which is convenient for time-frequency analysis.