Ukraine's secret weapon against planes: smartphones - voila! technology. The smartphones are open on listening mode and collect unusual sounds from the environment.
Another system, called Zouk, uses sensors and minicomputers instead of smartphones to detect unmanned aircraft at a distance of about 5 kilometers. Here, too, artificial intelligence is used to distinguish the special sounds made by rockets and tiny planes in flight from more routine sounds. Ukraine was recently attacked by 84 suicide drone attacks, but the systems were able to detect 80 of them in time.