Study on the Noise Reduction of Vehicle Exhaust NO_X Spectra Based on Adaptive EEMD Algorithm

Table 3

Denoising indexes of the three algorithms.

	SNR′/dB	SE	R	r
EMD LPF	21.1201	0.8017	0.9624	2.2094
Wavelet	22.8221	0.8023	0.9975	2.2236
NIO EEMD	28.1347	0.8025	0.9994	2.2455