Wave data transmitted
An internal processing unit called the Nortek Internal Processor (NIP) calculates wave height and direction estimates from the raw wave data (including pressure, velocities, and the surface elevation), and outputs the processed wave parameters to an acoustic underwater modem. The version of this system currently in operation uses LinkQuest UMW1000 acoustic underwater modems.
The acoustic modem on the receiving side can either be on land or mounted on a low cost surface buoy deployed in a sheltered area. From there the wave and current data are finally transmitted to shore using a radio link, GSM modems, or satellite. The underwater transmission system can even be used to transfer the data to a small boat passing over the AWAC installation. The download will be initiated from the topside, where the user onboard the boat stops the AWAC through the underwater modem, downloads the data stored on the recorder, and then restarts. The data accessibility is increased, and the need for large ships equipped with winches is eliminated.
The great thing about introducing internal wave processing and acoustic modem transmission is first, that the NIP greatly reduces the amount of data that needs to be transmitted. Consequently, an acoustic link becomes practical even over long transmission distances, due to that the required baud rate is reduced. Second, the need for long cables is eliminated, which significantly reduces cost and risk of damage.
It has never been easier to install and maintain an online wave and current system in areas with water depths ranging from 0 to 60 meters.
The Nortek AWAC, designed for high quality wave and current profile information, has rapidly become the standard for submerged wave measurement systems. It provides directional wave information from deployments as deep as 60 meters, for less than 2 seconds wave periods. The unique Acoustic Surface Tracking feature facilitates measurements of all types of waves, including irregular waves.