Abstract: Digital seismic data acquisition is an important part in earthquake observation, and analog-digital converter technology standards largely determine the quality of the data observation, and data acquisition will produce 1/f noise characteristic to the observation accuracy in the low frequency range. This paper discussed this issue based on an algorithm theory for improving the quality of seismic signals. We proposed an improved algorithm based on the autozero technology and modulation technology for weakening 1/f noise and imitated in the process. We also analyzed the energy loss of square wave and sine wave modulation and demodulation sequence as a weighted average for proposing the algorithm and proved the correctness of the weighted average algorithm in theory. Experimental data also show that the signal to noise ratio has been improved to some extent, and are well consistent with the calculated values.

Key words: Digital seismic data acquisition, Modulation and demodulation, 1/f noise