The current species and the role of satellites in China

Satellites are widely used and widely available. There are space "messenger" communications satellites, space "remote sensors" Earth resources satellites, space "weather stations" meteorological satellites, Space "guide" navigation satellites, space "spy" reconnaissance satellites, space "broadcast satellites", space "altimeter" satellites, Space "clairvoyance" astronomical satellites and so on. The formation of a large "satellite family."

The composition of Artificial Earth satellites
Satellites are generally made up of two major parts, the payload platform.

Payload refers to the satellite on the direct realization of the satellite's own purpose or scientific research tasks of the instrument and equipment. such as cameras used on remote sensing satellites, communication transponders and communication antennas used on communications satellites, the platform is the entire guarantee system for the normal operation of the payload, which generally includes the structural system and temperature control system. Power system, Radio measurement control system, attitude control system and track control system, etc.
The flying principle of Sputnik
Sputnik can be carried out on Earth's orbit. The first is because it has automatic (7.9 m/s), and it is because the Earth's gravitational force (centripetal force) has been pulling it, the string is pulling the same stone. Let's say the satellites are flying fast. When the centrifugal force exceeds the gravity of the Earth, satellite gatherings depart from the earth and fly to distant space.

The first five stars hanging in heaven
The first satellite was made in (the former Soviet Union), the second in Japan, and the third was the American explorer No. 1th. The fourth one is the French experimental satellite, and the fifth is the East China one.
Scientific exploration of satellites
Scientific exploration satellites are satellites used to probe the physical environment of space, and the main task is to probe the neutral particles in the space environment. High-energy charged particles, solid particles, low-frequency electromagnetic waves and plasma waves, magnetic fields, electric fields and so on.
Application satellite
Application of satellite is directly for the national economy and military services of artificial Earth satellites, according to the use can be divided into communications, meteorology, reconnaissance. Navigation. Land, Earth resources and multipurpose satellites.

Communications satellites
Classification of communication satellites
There are many types of communication satellites, which are divided by compact orbital communication satellites by orbit, flying compact orbital communication satellites, satellite broadcasting by use, tracking and data interruption of satellite maritime satellites and military communications satellites, etc.
Use of artificial satellites
The advent of satellites, especially the 3rd geostationary satellite, has made it possible for us to appreciate the wonderful live broadcast at home.

Navigating the Global Positioning system
"GPs", also known as the "navigation" is a constellation of 24 satellites, it can be anywhere on the earth in precise positioning.

A very small, very small receiver can be used to receive signals from 4 GPS satellites and calculate location data. Military horizontal distance and height accuracy are 5 meters, civil average is 15 meters
Global Navigation Satellite Systems
The Soviet/Russian development of the military global satellite navigation system and positioning system, its role and the United States to the navigation Star Global Positioning System the same.
Satellite navigation system
May 25, 2003 Zero 34 points, China in the Xichang Satellite Launch Center with the Long March third launch vehicle. The success of the third Beidou navigation satellite into space, which indicates that our country has established a good navigation system, the national economic construction will play an active role.
This launch is the third Beidou navigation and positioning satellite. The first two Beidou satellites were launched on October 31, 2000 and December 21, respectively.

The operation of navigation and positioning system is undecided. The launch is a backup star for the navigation and positioning system. It with the first two Beidou a complete satellite navigation and positioning system, to ensure all-weather, all day to provide satellite navigation information.
Meteorological satellite
Meteorological satellites can be divided into solar geostationary orbit meteorological satellites and Earth compact orbit satellites. Solar geosynchronous satellites patrol the Earth's surface two times a day.

Access to global meteorological data. Earth-orbiting meteorological satellites are capable of continuously conducting meteorological observations on 1/3 of the world's regions and transmitting meteorological data back to the ground in real time.
Resource satellites
The resource satellite is a satellite that surveys and studies the Earth's resources, and it can see the underground treasures, historical monuments, which are invisible to the human eye. Stratigraphic structure, can be a census of crops, forests, oceans. Air and other resources. Can predict and discriminate crop harvest, investigate and forecast all kinds of natural disasters.
return type Remote Sensing satellite
The return satellite is a low-orbit satellite, which is mainly used for three major purposes: a momentary observation of the earth, access to remote sensing information, and a microgravity experiment. Third, the technical reserve for the return of manned navigation.

Reconnaissance satellite
Reconnaissance satellites are used to collect and intercept military intelligence of the artificial Earth satellites, satellite reconnaissance advantages, is a wide range of reconnaissance. It is very important to strengthen military strength and comprehensive national strength, which is fast and can not be monitored regularly or continuously by the border of the country. In accordance with the difference between the device used and the reconnaissance task, the satellite is generally divided into photographic reconnaissance satellites and electronic reconnaissance satellites. Simultaneous marine surveillance satellites and early warning satellites.
Satellite applications in the national economy
Using the return satellite photograph, the area 6000 Yellow River delta dynamic monitoring square kilometer. Exploration area 13, sediment deposition, the estuary extends to the domestic 33.5 km.

The current species and the role of satellites in China