Van-Atta Acoustic Backscatter (VAB) is the first technology for ultra-low-power underwater networking and communication, which can transmit signals across kilometer-scale distances.
The technology builds on a technique we invented—called underwater backscatter—which communicates at 1 million times less power than existing underwater communication methods.
The newest generation of our technology is the first that can communicate at ultra-low power and over distances long enough to support practical applications in coastal monitoring, underwater climate change monitoring, weather prediction, disaster response, aquaculture, and much more.
How does it work?
Underwater backscatter nodes communicate by reflecting underwater acoustic signals. One challenge with our earlier generations is that they were not very efficient: they reflected signals in all directions. The key innovation in our newest design is that it can retrodirect its signal. Specifically, if sound arrives from a specific angle, it is re-transmitted back towards that same angle that it arrived from—this is retrodirectivity. The special configuration of piezoelectric transducers is known as a Van Atta array, and it sends incoming sound back in the direction that it came from instead of towards undesired directions, regardless of the array's orientation. This property enables the system to focus sound energy where it matters most, allowing the retroreflected sound to travel more efficiently and across longer distances. The operation of Van-Atta Acoustic Backscatter (VAB) is shown in the figure below.