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Jason Gobat

Senior Principal Oceanographer

Email

jgobat@apl.washington.edu

Phone

206-543-2439

Research Interests

Sensor-Platform Integration, Towed Vehicles, Autonomous Vehicles, Moorings, Cable Dynamics, Instrumentation, Data Telemetry

Department Affiliation

Ocean Physics

Publications

2000-present and while at APL-UW

Multi-month dissipation estimates using microstructure from autonomous underwater gliders

Rainville, L., J.I. Gobat, C.M. Lee, and G.B. Shilling, "Multi-month dissipation estimates using microstructure from autonomous underwater gliders," Oceanography, 30, 49-50, doi:10.5670/oceanog.2017.219, 2017.

More Info

1 Jun 2017

Ocean turbulence is inherently episodic and patchy. It is the primary mechanism that transforms water mass properties and drives the exchanges of heat, freshwater, and momentum across the water column. Given its episodic nature, capturing the net impact of turbulence via direct measurements requires sustained observations over extended temporal and/or broad spatial scales.

Towards real-time under-ice acoustic navigation at mesoscale ranges

Webster, S.E., L.E. Freitag, C.M. Lee, and J.I. Gobat, "Towards real-time under-ice acoustic navigation at mesoscale ranges," Proc. IEEE International Conference on Robotics and Automation, 26-30 May, Seattle, WA, 537-544, doi:10.1109/ICRA.2015.7139231 (IEEE, 2015).

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26 May 2015

This paper describes an acoustic navigation system that provides mesoscale coverage (hundreds of kilometers) under the ice and presents results from the first multi-month deployment in the Arctic. The hardware consists of ice-tethered acoustic navigation beacons transmitting at 900 Hz that broadcast their latitude and longitude plus several bytes of optional control data. The real-time under-ice navigation algorithm, based on a Kalman filter, uses time-of-flight measurements from these sources to simultaneously estimate vehicle position and depth-averaged local currents. The algorithm described herein was implemented on Seagliders, a type of autonomous underwater glider (AUG), but the underlying theory is applicable to other autonomous underwater vehicles (AUVs). As part of an extensive field campaign from March to September 2014, eleven acoustic sources and four Seagliders were deployed to monitor the seasonal melt of the marginal ice zone (MIZ) in the Beaufort and northern Chukchi Seas. Beacon-to-beacon performance was excellent due to a sound duct at 100 m depth where the transmitters were positioned; the travel-time error at 200 km has a standard deviation of 40 m when sound-speed is known, and ranges in excess of 400 km were obtained. Results with the Seagliders, which were not regularly within the duct, showed reliable acoustic ranges up to 100 km and more sparse but repeatable range measurements to over 400 km. Navigation results are reported for the real-time algorithm run in post-processing mode, using data from a 295-hour segment with significant time spent under ice.

Preliminary results in under-ice acoustic navigation for Seagliders in Davis Strait

Webster, S.E., C.M. Lee, and J.I. Gobat, "Preliminary results in under-ice acoustic navigation for Seagliders in Davis Strait," Proc., OCEANS 2014, 14-19 September, St. John's Newfoundland, doi:10.1109/OCEANS.2014.7003070 (IEEE, 2014).

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14 Sep 2014

This paper presents an under-ice acoustic navigation system developed for Seaglider, a buoyancy-driven autonomous underwater vehicle (AUV), and post-processed navigation results from one of fourteen glider deployments between 2006 and 2014 in Davis Strait. Seagliders typically receive all geolocation information from global positioning system (GPS) signals received while they are at the surface, and perform dead reckoning while underwater. Extended under-ice deployments, where access to GPS is denied due to the inability of the glider to surface, require an alternative source of geolocation information. In the deployments described herein, geolocation information is provided by range measurements from mooring-mounted acoustic navigation sources at fixed, known locations. In this paper we describe the navigation system used in Davis Strait and present navigation results from a six degree-of-freedom Kalman filter using post-processed navigation data.

More Publications

Inventions

Integrated RF Relay-GPS Board for Seaglider

Record of Invention Number: 48007

Jason Gobat

Disclosure

22 Mar 2017

Temperature Microstructure Instrument Controller Logger

Record of Invention Number: 47906

Luc Rainville, Jason Gobat, Adam Huxtable, Geoff Shilling

Disclosure

6 Dec 2016

Passive Miniature Acoustic Recorder for Seaglider

Record of Invention Number: 47208

Ben Brand, Jason Gobat, Adam Huxtable, Geoff Shilling

Disclosure

22 Jan 2015

More Inventions

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center
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