China has more than 300 satellites in orbit. What kinds of satellites are there?

Satellites generally consist of two parts, namely, the payload platform. Payload refers to the instruments and equipment used to directly realize satellite self-use or scientific research tasks, such as cameras used by remote sensing satellites, communication transponders used by communication satellites, communication antennas, etc. Platform is all supporting systems that serve the payload to ensure its normal operation, generally including structural system, temperature control system, power supply system, radio measurement and control system, attitude control system and orbit control system.

Scientific exploration satellite is a satellite used to detect the physical environment in space. Its main task is to detect neutral particles, high-energy charged particles, solid particles, low-frequency electromagnetic waves and plasma waves, magnetic fields, electric fields and so on. Application satellite is an artificial earth satellite that directly serves the national economy and military affairs. According to the purpose, it can be divided into communication, meteorology, reconnaissance, navigation, geodesy, earth resources and multi-purpose satellites. There are many kinds of communication satellites, which are divided into geostationary orbit communication satellites and flying geostationary orbit communication satellites according to their orbits. According to the purpose, there are direct broadcast satellites, tracking and data interruption satellites, maritime satellites and military communication satellites. With the appearance of artificial satellites, especially since the third geosynchronous satellite realized global communication, we can enjoy wonderful live broadcast at home.

Global positioning system? Also known as? Navigation? A constellation of 24 satellites can accurately locate anywhere on the earth. Users can use a very small receiver to receive signals from four GPS satellites and calculate position data. The accuracy of military horizontal distance and height is 5 meters, and the civilian average is 15 meters. Global navigation satellite system, a military global satellite navigation system and positioning system developed by the Soviet Union/Russia, has the same function as the global positioning system of the United States.

Meteorological satellites can be divided into sun-synchronous orbit and geostationary orbit. Sun-synchronous orbit meteorological satellites patrol the surface twice a day. Global meteorological data are available. Geosynchronous orbit meteorological satellites can carry out continuous meteorological observation in the global 1/3 range and transmit meteorological data to the ground in real time. Its resource satellite is a kind of satellite that measures and studies the earth's resources. It can see the invisible underground wealth, historical sites, stratum structure, crops, forests, oceans, air and so on through the stratum. Can predict and identify crop yields, observe and predict various natural disasters.

Reconnaissance satellite is an artificial earth satellite, which is used to collect and intercept military intelligence. The advantages of satellite reconnaissance are wide reconnaissance range, high speed and no national boundaries. It can monitor a certain area regularly or continuously, which is of great significance for enhancing a country's military strength and comprehensive national strength. Reconnaissance satellites are distinguished according to the tasks performed and the reconnaissance means adopted. Generally divided into photographic reconnaissance satellites, electronic reconnaissance satellites, marine surveillance satellites and early warning satellites.