1937, American Gerot Raber built an antenna with a diameter of 9.5m in his backyard, received radio waves from the center of the Milky Way in 1939, and drew the first radio star map according to the observation results, thus radio astronomy was born. The antenna used by Rabe is the first radio telescope dedicated to astronomical observation in the world.
In the 1960s, there were four very important discoveries in astronomy: pulsars, quasars, cosmic microwave background radiation and interstellar organic molecules, which were called "four great discoveries", all related to radio telescopes.
In 1960s, the largest single aperture radio telescope was 305 meters in diameter.
1962, martin ryle of Cavendish Laboratory of Cambridge University invented the synthetic aperture radio telescope by using the principle of baseline interference, which greatly improved the resolution of the radio telescope. The basic principle is that two separate radio telescopes receive radio waves from the same celestial body, and the two beams of light interfere with each other. The highest equivalent resolution can be equivalent to a single-aperture radio telescope with a caliber equivalent to the distance between the two places. Ryle won the 1974 Nobel Prize in Physics for this invention.