If you played the 'Harpoon' paper and pencil naval wargame in the late 80s, early 90s - not the later computer game that was based on the board game - this system was available to British ships in the Falkland Island scenarios. Given that the rules for the game were based on openly published data, I don't see how this is really 'news' to anyone. A quick search shows that there are references to this system in other publications in the 90s as well. The game effect was to cause planes at low altitude to break off their attack. For planes at very low altitude, namely Argentine pilots trying to fly below the engagement altitude of British SAMs, there was a percentage chance the plane would crash into the water.