Abstract
We developed a new low-cost data logger KS-002D for the CEORKA strong-motion network. The data logger can send the observed continuous data in real-time through Internet connection and back-up the same data in large-capacity memory card inserted into the data logger. These features solve the significant problems of the previous CEORKA's system. The new data loggers were installed progressively in CEORKA's stations from March 2009 and the full-scale operation of the new observation system started in August 2011. The new system realizes real-time continuous observation, while maintaining the previous observation system in the same time.The accuracy of the new data logger were verified by comparison with several event and microtremor records obtained by the old data logger and the strong motion seismograph that can measure microtremors. The results for event records show the same or better accuracy obtained by the old data logger. On the other hand, microtremor records show somewhat lower accuracy in high-frequency range at the hard bedrock station, although accuracy of other records is the same as obtained by the strong motion seismograph that can measure microtremors. Above verification results show that the new data logger can obtain broadband and high-accuracy data ranging from strong motions to microtremors.
