An autonomous oceangoing robot maintains a satellite link to shore bases even in rough seas, thanks to an Agile Aperture Antenna developed by researchers at the Georgia Institute of Technology.
The robot, called the Wave Glider, was built by Liquid Robotics Inc. in Sunnyvale, Calif. The antenna consists of a thin dielectric substrate supporting an array of square metallic patches that can be switched on or off to steer the outgoing beam or optimize the incoming signal. The antenna tracks its position and orientation relative to the satellite without any input from other components on the Wave Glider. The antenna consumes 0.25 W of power, which it gets from solar panels on the craft, and can switch up to 1,000 beams/sec while transmitting data at 200 kbits/sec. Originally developed for the military, it takes up less space and uses less power than a gimbaled antenna or phased array.
The Wave Glider gets electricity for propulsion by harvesting energy from the motion of the ocean. It can transmit video, audio, or environmental data such as salinity, temperature, or dissolved oxygen, to an Earth station via satellite. It could also be used for security purposes.