Abstract
The GPS ocean wave meter (GPS buoy) has been installed at 18 sites around Japan for NOWPHAS(The Nationwide Ocean Wave information network for Ports and HArbourS) of Ports and Harbours Bureau, Ministry of Land, Infrastructure, Transport, and Tourism, it measures ocean waves in the offshore. The unit installed some 20 kilometers off the coast of Kamaishi City, Iwate Prefecture, measured the tsunami triggered by the Great East Japan Earthquake of 2011 and helped the Japan Meteorological Agency to update its tsunami warnings. To ensure early detection of tsunami, it is necessary to install it farther than the existing GPS buoy. However, the existing GPS buoy can be only installed within some 20 kilometers from the coast, because the real-time kinematic (RTK) method and wireless data transmission was adopted. This paper reports the summary of the new GPS ocean wave meter and the demonstration experiments for hydrographic phenomenon in the offshore.
