The DART system consists of a bottom pressure recorder (BPR) located on the sea floor capable of detecting a tsunami as small as 1 centimeter high on the ocean surface. A discus-shaped buoy, 2.5 meters in diameter, on the ocean surface is moored at a position close enough to receive data via acoustic link from the BPR. After receiving data from the BPR, the surface buoy relays the information via the NOAA Geostationary Operational Environmental Satellite (GOES) system to ground stations. The ground stations demodulate the signals and disseminate information to NOAA Tsunami Warning Centers (TWC) and the Pacific Marine Environmental Laboratory. TWCs use the data in real time to decide what U.S. coastal communities need to be warned of impending danger from a tsunami.