Abstract:Along with development of techniques of seismic exploration,the equipped and real-time acquired number of channel can reach to ten thousand and hundred thousand channels,raising the higher demand on efficiency testing property index of seismic data acquisition system in a precondition of without decreasing test precision.Starting from computational formula of total harmonic distortion and FFT operational structure,the paper presented the FFT Pruning algorithm testing total harmonic distortion of seismic data acquisition system,the kernel of which is only to compute butterfly operation nodes contributing objective output,and key lies on using forward-order input and reverse-order output to determine the butterfly operation nodes relative to anticipated output,creates computational path from input data to anticipated output and computes amplitudes of elemental and various harmonic waves in testing data based on determined butterfly operation nodes,and further computes the total harmonic distortion of data-acquired channels.The theoretical analysis and practical computational results showed the computational precision of FFT Pruning algorithm is totally same as standard algorithm,but greatly reduces operational effort,which is suitable for field or indoor test of the index of total harmonic distortion of seismic data acquisition system with larger number of channels.