Radar astronomical observation
Radio waves in the 20th century
This entry is missing Overview , add relevant content to make the entry more complete, and it can also be upgraded quickly. Hurry up edit Come on! Radar astronomical observation is the radio wave of the 20th century.
- Chinese name
- Radar astronomical observation
- Field
- Astronomy
- start time
- Twentieth Century
Radar astronomical observation It is a branch that began in the 20th century. It uses radar to send radio waves to celestial bodies (or artificial celestial bodies) and receive reflected echoes. Through processing and studying the echoes, it discusses the physical and geometric properties of celestial bodies. Astronomical radar is basically consistent with general radar in working principle and structure. It is mainly composed of transmitter, receiver and recorder. The transmitter generates high-frequency signals, It is sent to the antenna through the change-over switch to launch towards the celestial body; At this time, the change-over switch immediately disconnects the antenna and transmitter, and connects with the receiver. After a period of time, the signal reflected from the celestial body enters the receiver from the antenna, and then is recorded by the recorder. The delay time is displayed. Astronomical radar differs from general radar in that: (1) the detection target is thousands or tens of thousands of times away, so the time delay of receiving and transmitting signals is large; (2) Large antenna aperture and strong transmitter power; (3) The echo will be generated due to the large detection target Doppler broadening Astronomical radar can accurately measure echo delay Distance of celestial bodies And position, which is useful for calculating the precise orbit and related astronomical constants of the interplanetary rocket; Calculate the perturbation effect of other celestial bodies on the measured celestial bodies, and check General relativity Expected minor impact; By measuring the Doppler broadening , can calculate the rotation period and orbital inclination of planets or asteroids; Radar astronomy can also detect the spatial distribution and physical state of meteors, as well as the surface structure of planets and satellites 
