Glider Navigation

GNT Development & Testing

Development of current-forecast based glider navigation tool (GNT)

Ocean gliders fill the gaps between coastal and open ocean observing systems, between Argo floats, and moorings and ship-based strategies. However a lot of effort is expended on making glider go to where they are supposed to go. We took the approach of using current models to improve the glider speed towards its target point. Such glider navigation tool (GNT) reduces pressure on pilots especially in long missions and improves the overall success of the mission.

Schematic of the navigation process using the GNT: 1st the user initiates a navigation request, the tool then computes the route from A to B and uploads the result to the glider. Complex paths involving multiple target points are in the works.

Over the past year months we developed and tested the new Glider Navigation Tool (GNT). Based on tests in the Gulf of St. Lawrence and the Labrador Sea we see a % improvement in overall glider efficiency in reaching its target. This has implications for glider users trying to track ocean features and those operating fleets of gliders to measure certain ocean regions in specific time intervals. The GNT gives glider users a better way to control the glider behavior once deployed.

The GNT works by choosing the best glider path that minimizes glider head on currents, weighing both historic and forecast current data for a region. This kind of optimized glider path planning has tremendous value for improving the autonomy of gliders in operational ocean monitoring applications. Also from glider deployments in the Labrador Sea and the Gulf of St. Lawrence we were able to validate the models based on the depth averaged glider speeds.

24-HR forecast HYCOM and depth averaged glider current speed for the period of glider data downloaded so far.

So far we have implemented local current models in the Gulf of St. Lawrence and a global model for navigating the gliders from HOTSeALS.

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