NDBC OWL Wave System Development

The U.S. National Oceanic and Atmospheric Administration's (NOAA) National Data Buoy Center (NDBC) is developing a new wave observation system named Ocean Wave Linux (OWL). OWL will replace the NDBC's older and now obsolete Digital Directional Wave Module (DDWM). The OWL uses the existing DDWM processing algorithm but is implemented with Linux-based modern processing hardware and a high performance motion sensor. These improvements avoid parts obsolescence and lower power demand. The OWL consists of a nine axis motion sensor, a Linux processing board, and a custom NDBC circuit board that provides control and data collection. The NDBC performed extensive tests to verify proper code operation, motion sensing, and operation of the electronics. Tests included using the NDBC's Desktop Wave Simulator (DTWS) and the Ocean Wave Instrumentation Facility (OWIF) to simulate wind and swell ocean waves, respectively. Other laboratory tests were conducted to confirm proper operation at extreme cold and heat (e.g. twenty degrees below Celsius and fifty degrees above Celsius) and to measure power consumption. The OWL achieves a sixty-five percent reduction in power consumption as compared to DDWM. Test systems that incorporate both the older DDWM and OWL systems in one enclosure have been fabricated, bench tested, and one deployed for field evaluations at the NDBC 46022 station. The OWL's wave height and period compared well with the collocated DDWM and a Waverider located approximately twenty-five kilometers away. Further collocated tests between the DDWM and OWL and a Datawell Waverider are planned for other West Coast and East Coast locations.