Fig. 2From: Improved shift-invariant sparse coding for noise attenuation of magnetotelluric dataResults of the charge–discharge-like noise processing. a Original noise-free MT signal; b synthetic noisy signal; c de-noised by pulse dictionary-based method (PSO-PD); d de-noised by ISISC. The left panels are time domain waveforms and the right panels are their spectraBack to article page