Trajectory Buoys

Small buoys equipped with GPS sensors were used to track drifting material on the ocean surface. Initial design constraints included:

• Simplified design to minimize assembly time

• Packing volume reduction for easy bulk transport

• Reduced cost

• Center of buoyancy (VCB) above center of mass (VCG)

• Elevation of the GPS unit above float to minimize water exposure and allow access to switch

For the second iteration, we developed a new generation of buoy to meet ecological impact reduction goals. We replaced the buoyant foam with a formed aluminum enclosure, reduced plastic content, increased reliability, and decreased power consumption by developing a new PCB.

The first deployment-ready version of the trajectory buoy (left) and the dematerialized, refined version two (right) with 59% reduced system mass and 54% reduced plastic mass.

Trajectory buoys reported their position regularly, which we tracked on the Deployment Dashboard.

Deployment dashboard, developed by our software team, which allowed us to track the location of deployed hardware in nearly real-time.

Hardware trajectories were used to tune trajectory models, described in the Ocean Modeling section.