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

Table 3

Characteristic indicators of the signal after wavelet and EEMD joint denoising.

SNR	RMSE	Amplitude of the fundamental A1 (mV)	Amplitude of the second harmonic A2 (mV)	Relative error A1 (%)	Relative error A2 (%)	Relative error (%)
16.89	10.12	9160	1662	2.64	1.78	7.32