Abstract
GPS on Every Roof is used for post-seismic building-wise damage detection. Wireless sensor nodes equipped with a GPS receiver are installed on the top of the roof. The displacement of the roof caused by the earthquake is measured. On-board analysis of GPS data reduces the amount of wireless communication data. However, the high-performance CPU which can perform double-precision arithmetic has a high energy consumption. Reduction of energy consumption is preferable because the sensor network should run as long as possible with limited energy supply. For this purpose, the new sensor node called "Hybrid Sensor Node" has two CPUs: the high-performance CPU and the low-power CPU. The high-performance CPU is used only for on-board GPS analysis. The low-power CPU is used for other tasks such as controlling the wireless communication module and the GPS receiver. The results from a field experiment show that the running time of the high-performance CPU is reduced 576sec to 10sec while achiving the target value of the required time and the positioning accuracy.
