Ocean Based Sensor Systems

Autonomous Surface Vessel (ASV)

SeaLandAire’s ASV allows for remote monitoring of underwater and/or atmospheric conditions via a satellite link. The ASV may be commanded via a satellite communication link to stay in one location (Station Keep) or move as required by the mission. Long life is provided by a combination of energy harvesting techniques from the ocean surface and low power consumption by efficiently designed components.

Why Autonomous Surface Vehicles?

Advantages:

Unmanned

Lowers operational risk
Lowers operational cost

Distributed

Low risk
Wide aperture

Small

Covert
Lowers unit cost

Autonomous

Minimizes human load
Reacts more quickly to situations than remote unmanned vehicles

Types of missions:

Un-moored station keeping
Tracking
Search

Advancements by SeaLandAire

Energy harvesting
Stand off deployment
Propulsion efficiency
Miniaturization
Modularity

Autonomous, long life, and cost effective deployments of unmanned, small sensor system for long term surveillance, data acquisition, or communication with subsurface assets is the objective of the ASV. ASV’s must overcome the difficulties of station keeping and maneuvering in adverse ocean environments, to successfully achieve utility. To allow extended system life without necessitating very large, heavy, and volatile onboard energy source, it is necessary that the ASV have the capability to extract energy from the surrounding environment. The global variations between deployment environments, combined with the extended life of the mission, require the system to efficiently harvest or harness energy from as many sources as possible.

SeaLandAire is advancing ASV technology by developing a design that harvests energy from solar radiation, wind, vertical and horizontal wave motion. A navigational system, and a power management system, coordinated by an innovative Learning Adaptive Control algorithm, enables our system to efficiently use the harvested and harnessed energy to station keep or maneuver against the local drift-causing forces, using both a sail and a high efficiency thruster motor specifically designed for the ASV application.

Drifter Buoy

SeaLandAire has experience with Drifter buoys. These buoys are typically expendable and therefore require a lower cost. Data is collected from the buoy and the buoy is commanded using UHF communications. Drifter buoys are typically deployed either by aircraft or over the side. The advantage of the drifter buoy is to lower the relative flow between the acoustic sensor and the water column allowing for lower system noise.

SeaLandAire’s experience comes from both past experience with sonobuoys and current efforts for a marine mammal detection buoy and current developmental efforts with a miniaturized directional buoy.

Moored Buoy

Moored buoys are used when monitoring occurs at one location. These buoys are typically deployed in shallow water due to the expense and complexity of the system if deployed in deep water. A moored buoy may have a multiplicity of sensors on it ranging from acoustic, to environmental sensors. A moored buoy will typically have a rechargeable battery pack that is located in the surface unit. Depending on the intended duration of the buoy, the buoy may have a solar panel that allows the batteries to recharge.

SeaLandAire has experience working with moored buoy systems and is familiar with the dynamics involved with surface motion and in providing a long term reliable system. The buoy will have higher flow noise than a drifter buoy and therefore special procedures must be implemented with flow shields to minimize the flows effect on system noise.