Abstract: As one of effective ways to mitigate earthquake hazards, earthquake early warning (EEW) is studied by many countries and regions in the world and there is significant mitigation effectiveness during practical application. However, all the realtime data transferring in these EEW systems are organized in one packet per second and a certain delay exists when using first three seconds data of P wave for τ_c & P_d calculation. Especially, when P wave starts at the first part of a data packet, the delay is more than 0.5 s. Furthermore, the acquired data can't be used for a variety of research purposes simultaneously because only one sampling rate data is outputted at the same time. In order to solve these two problems, we develop a lowlatency data acquisition system for EEW. It can transfer realtime data by one packet per 100 ms so that the leading time can be improved with 0.8 s at maximum. In addition, we also add multisampling rate data output function which can improve utilization rate of the seismometer output data by making its data available for global seismic studies (1 Hz) and conventional seismic observation (50/100/200 Hz).

Key words: Data acquisition, Low-latency, Earthquake early warning, Embedded Linux