Abstract:According to the principle of centrifugal force generated by the object rotating around the origin and the synthesis and counteraction of centrifugal force, two servo motors are used to drive two eccentric masses to rotate at the same time, and linearly change the rotation frequency of the servo motors through the Beidou timing control system, so as to develop a controlled accurate seismic source (CASS), which launches a linear frequency modulation (LFM) signal to the ground. The energy of LFM signal has good aggregation characteristics. We calculate the initial frequency and frequency modulation rate of LFM signal by Wigner-Hough transform. CASS is a kind of green source with long-term operation and high repeatability. It can be applied to monitor the fault activity, receive the LFM signal reflected to the ground from subsurface interface at different depths, quantitatively analyze the temporal variation law of the wave velocity on the same path, study the relationship between spatio-temporal evolution characteristics of the fault activities and the occurrence of earthquake, and explore the numerical earthquake prediction.