Radio Interferometry
In 1946, a technique called astronomical interferometry was developed. Astronomical radio interferometers usually consist either of arrays of parabolic dishes or two-dimensional arrays of omni-directional antennas. All of the telescopes in the array are widely separated and are usually connected together using coaxial cable, waveguide, optical fiber, or other type of transmission line. Interferometry increases the total signal collected, but its primary purpose is to vastly increase the resolution through a process called Aperture synthesis. This technique works by superposing (interfering) the signal waves from the different telescopes on the principle that waves that coincide with the same phase will add to each other while two waves that have opposite phases will cancel each other out. This creates a combined telescope that is equivalent in resolution (though not in sensitivity) to a single antenna whose diameter is equal to the spacing of the antennas furthest apart in the array.
Read more about this topic: Interference (wave Propagation)
Famous quotes containing the word radio:
“Now they can do the radio in so many languages that nobody any longer dreams of a single language, and there should not any longer be dreams of conquest because the globe is all one, anybody can hear everything and everybody can hear the same thing, so what is the use of conquering.”
—Gertrude Stein (1874–1946)