This paper presents the seismic data lossy compression method using biorthogonal wavelet transform,which has advantage of easy achievement and small distortion in the case of high compression ratio and so on.The signal distortion caused by compression with the characteristic parameters of seimic events is analyzed.The results show that the calculated maximum magnitude error is 8.6×10-3,and the maximum epicenter distance error is 3.69 km when the compression ratio is in the range of 0~31.

The borehole comprehensive observation sysyem is used for monitoring seismic precursor information,and the borehole magnetometer is one part of the system.The paper introduced the design of the digital circuit and the inbeded program of the magnetometer,including the control hardware design using MSP430F1611 MCU,high-precision A/D conversion circuit,background magnetic field compensation circuit which can be auto hand operated,program design of protocol analysis and data transimission,etc.The results of practical observation at Jinhai Seismic Station show:a)the magnetometer is reliable on continuous observation;b)it's veracity of mearsure is high,which resolution is 0.043nT;and c)magnetometer meet the demand to auto remote-monitor control.