IBuoy: Expendable Echo Sounder Buoy with Satellite Data Telemetry

The IBuoy is a small expendable buoy platform with satellite data telemetry that can be deployed for different measurements, such as a wave spectrum (Porter and Keller, 2012). The IBuoy in its wave measuring version allows a user to deploy a small float, (25 cm high, 30 cm in diameter, 2.8 kg), which measures the instrument's motion for 20 minutes, processes the data for 5 minutes, and telemeters the processed data via Iridium modem to the user. In the spring of 2012 this system was modified by replacing the internal motion sensor with a connection to the Lamont-Doherty Earth Observatory's (LDEO) prototype Seafloor Sounding in Polar and Remote (SSPARR) echo sounder (Anderson et. al, 2005). From May 3 through May 19, 2012, this prototype was deployed nine times during the NSF-funded Switchyard field program at thin hole rosette sites (Smethie et. al, 2011). At three sites it was deployed in the beacon-mode, and at six other sites in the SSPARR mode with one of the sites being within ~400 km of the North Pole. In beacon-mode the IBuoy reports positions over time allowing accurate estimates of true ice motion. When it is in the beacon- and depth-mode, an acoustic transducer is deployed through a 12 inch hole in the ice and connected to the SSPARR sounder with the IBuoy on the ice surface. In this configuration it measures the water depth from the submerged transducer to the ocean floor below. Now that the concept has successfully been tested, the goal is to deploy similar IBuoy/SSPARRs at a number of sites for a season and collect positional data and depth soundings as the ice moves. The IBuoy concept provides a highly capable inexpensive platform that can be configured for a variety of measurements. References: Porter, D. L. and K. H. Keller, "IBuoy: Expendable Short Time Duration Wave Buoy with Satellite Data Telemetry," OCEANS '12, Hampton Roads, VA, 14-19 October, 2012. Smethie, W.M. Jr., D. Chayes, R. Perry, and P. Schlosser. 2011. A lightweight vertical rosette for deployment in ice-covered waters. Deep-Sea Research Part I, http://dx.doi.org/10.1016/j.dsr.2010.12.007. Anderson, R., D. Chayes, et al. (2005). "Seafloor Soundings in Polar and Remote Regions - A new instrument for unattended bathymetric observations," Eos Trans. AGU 86(18): Abstract C43A-10.