Warning system
"K-19", the first nuclear-powered Russian boat, was commissioned on 30 April 1961. The military at that time considered the single greatest security threat to the USA the possibility of a submarine-delivered nuclear warhead placed near a major American city. Artemis was considered part of an underwater Defense Early Warning system. However, it was discovered that the Soviet boats were particularly noisy. Rapid advances in computer technology and the development of signal processing algorithms, such as the Fast Fourier transform, quickly gave the West the superior military position using multiple passive SOSUS arrays. In 1961, SOSUS tracked USS "George Washington" from the United States to the United Kingdom. The next year SOSUS detected and tracked the first Soviet Diesel submarine.