In the United States, the technology was demonstrated during December 1934, although it was only when war became likely that the U.S. recognized the potential of the new technology, and began development of ship- and land-based systems.
Di Amerika Serikat, teknologi yang ditunjukkan selama Desember 1934, meskipun itu hanya ketika perang menjadi mungkin di mana AS menyadari potensi dari teknologi baru, dan mulai pembangunan sistem berbasis kapal dan darat.