Summary: | The principal investigators of this project propose to design and develop an integrated underwater acoustic sensor network for ice-covered seas. The sensor and communication network will support 1) long-term, intelligent distributed Arctic observing systems, 2) assimilation of remote-sensing and in-situ under-ice measurements, and 3) regional and global climate modeling with real-time measurements. Such a network holds the promise to revolutionize under-ice ocean sampling in polar regions. Ocean temperature, conductivity, and pressure are transmitted acoustically via a small network of three acoustic modems over 20-40 kilometer (km) ranges. Each of two ocean sensors is connected to an acoustic modem that transmits and receives data from all other elements of the network. A third modem receives the data and passes it via a 7-conductor cable from below the sea ice to a data logger of an automated weather station. The weather station then forwards the ocean data via Iridium to the internet thus connecting remotely sensed ocean data near Moltke Glacier in Wolstenholme Fjord to anyone anywhere. The networked acoustic modem operate at 3500 Hertz (Hz) with a bandwidth of 1250 Hz that facilitated data through-put rates of about 500 bits per second over ranges that exceed 40 km. Both direct (Modem-A to Base and Modem-B to Base) and indirect (Modem-A to Modem-B to Base) transmission were received successfully.
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