He is known mostly for having discovered, before e.g.
Edmund Whittaker,
Harry Nyquist, or
Claude Shannon, the
sampling theorem in 1933 (and hence, in Russian literature, it is known as the Kotelnikov's theorem). This result of
Fourier analysis was known in
harmonic analysis since the end of the 19th century and circulated in the 1920s and 1930s in the engineering community. He was the first to write down a precise statement of this theorem about signal transmission. He also was a pioneer in the use of
signal theory in modulation and communications. He is also a creator of the
theory of optimum noise immunity. He obtained several scientific prizes for his work in
radio astronomy and
signal theory. In 1961, he oversaw one of the first efforts to probe the planet
Venus with radar. In June 1962 he led the first probe of the
planet Mercury with radar. Kotelnikov was also involved in
cryptography, proving the absolute security of the
one-time pad; his results were delivered in 1941, the time of Nazi Germany's invasion of the Soviet Union, in a report that apparently remains classified. In this, as with the above-mentioned sampling theorem, he and
Claude Shannon in the US reached the same conclusions independently of each other. For his achievements, Kotelnikov was awarded the
IEEE 2000 Gold Medal of Alexander Graham Bell and the honorable IEEE Third Millennium Medal. Prof.
Bruce Eisenstein, the President of the IEEE, described Kotelnikov as follows: "The outstanding hero of the present. His merits are recognized all over the world. In front of us is the giant of radio engineering thought, who has made the most significant contribution to media communication development". ==Honours and awards==