Application of Wavelet and EEMD Joint Denoising in Nonlinear Ultrasonic Testing of Concrete

Table 1

Characteristic indicators of the numerical signals after adding noise.

SNR	RMSE	Amplitude of the fundamental A1 (mV)	Amplitude of the second harmonic A2 (mV)	Relative error A1 (%)	Relative error A2 (%)	Relative error (%)
6.54	33.31	9293	2187	1.22	33.93	37.26