China Sky Eye is a radio telescope of the National Astronomical Observatories of the Chinese Academy of Sciences, located in Guizhou Province, China, the main project started construction in 2011, completed in 2016, and officially started operation in 2020; It is currently the world's largest radio telescope with a filled aperture (all aperture with reflective surfaces).
China's Sky Eye is a 500-meter aperture radio telescope, which is different from the optical telescopes we often see in our lives in that optical telescopes observe the universe through visible light, and radio telescopes observe the universe by receiving invisible radio waves in the universe.
Visible light and radio are two different electromagnetic waves, visible light is an electromagnetic wave that can be perceived by the human eye, it has a shorter wavelength and is able to be absorbed by oxygen and water vapor in the atmosphere, so it can only travel within the atmosphere. Visible light is the most common light in our daily lives, and we perceive and observe things around us through our eyes.
Radio waves are a type of electromagnetic wave with a longer wavelength that is able to penetrate the atmosphere and travel through space. Radio waves can be received and transmitted through antennas and are used in fields such as communications, broadcasting, radar, and astronomical observations. Through radio waves, we can transmit and receive information, detect and study radio signals in the universe.
Visible light and radio waves have their own characteristics and advantages in applications and observations. The visible light window is the main means for human beings to observe the universe, and through the visible light telescope, galaxies, stars, planets, nebulae and other celestial bodies can be observed. The radio window can penetrate the occlusion and observe objects obscured by visible light, such as dust clouds, interstellar gas, etc. Through the frequency and wavelength of radio waves, we can study the physical properties, structure, and evolution of celestial bodies and explore the mysteries of the universe.
The composition of China's Sky Eye includes several parts, including an active reflector system, a feed support system, a measurement and control system, a receiver and a terminal, and an observation base.
It is the core part of China Tianyan, which is composed of tens of thousands of steel cables and 4450 reflective units. It resembles a huge pot and has a reception area equivalent to 30 standard football fields.
The surface of the active reflective surface is made up of 4,450 triangular pieces, each side is about 11 meters long, forming the form of a geodesic dome. With the 2,225 winches underneath, the joints between the panels can be adjusted so that the flexible cable bracket is deformed into a parabolic antenna aligned with the desired sky direction.
The main reflector is fixed in the karst terrain of a natural depression and focuses the received radio waves on the one suspended 140 meters above it"Feed cabin"on the receiving antenna. The main reflector is made of perforated aluminum sheets, supported by a steel cable mesh suspended from the wheel flange.
Above the main reflector, there are six tall towers supporting a lightweight cable robot"Feed cabin"。The receiving antenna is mounted underneath the Stuva platform to provide fine position control and compensate for interference such as wind movements, enabling pointing accuracy of up to 8 arc seconds.
The feed module is simply understood: the main structure of the Chinese Sky Eye is a huge parabolic reflector with a diameter of 500 meters, consisting of about 4,400 adjustable aluminum plates. The shape and curvature of this parabolic reflector are precisely designed to focus the radio waves to the focal position of the receiver. At the focal point, there is a highly sensitive receiver for receiving and recording radio signals from celestial objects.
The basic principle is to use the principle of parabolic reflection to collect radio wave signals emitted by celestial bodies for radio astronomy observations.
The large reflective surface of China's Sky Eye allows it to receive more radio signals, which improves the sensitivity and resolution of detection. It can detect fainter and more distant celestial objects, helping scientists study various phenomena in the universe, such as pulsars, galaxies, galaxies, etc.
On February 23, 2024, the 500-meter aperture spherical radio telescope FAST in Guizhou Province continued to observe the sky. With the ultra-high sensitivity of the telescope, the number of pulsars monitored by FAST has reached 883, which is more than three times the number of similar telescopes monitored by foreign telescopes in the same period since its operation.