• Weight: 52 kg
• Hull Diameter: 21.3 cm
• Vehicle Length: 1.5 meters
• Depth Range: 4–200 meter (coastal model) or 1000 meter (1-km model)
• Speed: 0.4 m/sec horizontal average
• Endurance: Typically 30 days, depending on measurements and communication
• Range: 1500 km
• Navigation: GPS, magnetic compass, altimeter, subsurface dead reckoning
• Sensor Package: Conductivity, Temperature, Depth
• Communications: RF modem, Iridium satellite, ARGOS, Telesonar modem

 

The principle advantages of Autonomous Underwater Vehicle Gliders (AUVGs) are:

1. Very suitable for long-range and endurance, if low to moderate speed is acceptable.
2. The sawtooth profile is optimal for both vertical and horizontal observations in the water column.
3. Regular surfacing is excellent for capturing GPS and two-way communication. No other navigational aids are required and the system is very portable.

Forward Propulsion
Gliders are unique in the AUV world, in that the forward propulsion is created by varying vehicle buoyancy. Wings and control surfaces convert the vertical velocity into forward velocity so that the vehicle glides downward when denser than water and glides upward when buoyant (Fig 1). Gliders require no propeller and operate in a vertical sawtooth trajectory.

Fig 1. Force balance diagram of forces acting on Glider, angle of attack not included.

Navigation and Flight
The Slocum Battery Glider dead reckons to waypoints, inflecting at set depths and altitudes based on a mission text file. As set by the mission, the Glider periodically surfaces to communicate data and instructions and to obtain a GPS fix for location. Any difference in dead reckoning and position is attributed to current, and that knowledge is used on the subsequent segment.