What is the function of artificial satellite?
Uses of artificial satellites Artificial earth satellites operate in their respective orbits, but their functions and uses are different, which can be roughly divided into five categories: communication, meteorology, resources, reconnaissance and navigation. :: Communications satellites. Its function is to transmit TV and telephone signals for people. Without it, it is difficult for you to make overseas calls or watch world news and international competitions. Meteorological satellite: The remote sensing equipment it carries can overlook the whole earth's atmosphere and monitor the wind, clouds, rain and forest fires on the earth. Images and data recovered by meteorological satellites are the basis for meteorological scientists to accurately predict global weather. * Earth resources satellite, which uses remote sensing instruments to find geographical features that are difficult to find on the ground and at low altitude, and uses the information obtained by it to accurately estimate the resources of vegetation, geology, hydrology and seawater in various regions of the earth. Reconnaissance satellites, with high-resolution cameras and video cameras, can accurately reflect the mobilization and assembly of ground troops and the changes of various military facilities. :: Navigation satellites help ships sailing at sea identify their directions and positions. By observing and ranging more than two satellites, a ship can accurately know the coordinates of its geographical position.
artificial satellite
Satellites generally consist of dedicated systems and support systems. Dedicated system refers to the system directly related to the mission performed by the satellite, also known as payload. According to the various uses of satellites, special systems using satellites include: communication transponders, remote sensors, navigation equipment, etc. The special system of scientific satellite is various instruments such as space physical exploration and astronomical exploration. The special system for technical test satellite is the test equipment for various new principles, technologies, schemes, instruments and equipment and new materials. Support system refers to the system that ensures the normal work of satellites and special systems in space, also known as service system. It mainly includes structural system, power supply system, thermal control system, attitude control and orbit control system, radio measurement and control system, etc. For recoverable satellites, there is also a return landing system.
The orbit of artificial satellite depends on the mission requirements of satellite, which can be divided into low orbit, medium-high orbit, geosynchronous orbit, geostationary orbit, sun-synchronous orbit, elliptical orbit and polar orbit. Satellites fly around the earth at high speed. Low-orbit and medium-orbit satellites can fly around the earth several times to a dozen times a day, which is not limited by geographical, airspace and geographical conditions and has a wide field of vision. It can quickly exchange information with the ground, including the forwarding of ground information, and can also obtain a large number of remote sensing information of the earth. The remote sensing area of an Earth resources satellite image can reach tens of thousands of square kilometers.
When the orbit height of the satellite reaches 35,800 kilometers and it flies in the same direction as the earth's rotation over the equator, the period of the satellite's rotation around the earth is exactly the same as that of the earth's rotation, and its relative position remains unchanged. This satellite looks like it is still hanging in the sky on the earth, and it is called the geostationary orbit satellite, which can realize the uninterrupted information exchange between the satellite and the ground station and greatly simplify the equipment of the ground station. The vast majority of TV relay and forwarding communication through satellites are realized by stationary communication satellites. Recommended reading: Decryption of Saturn's Halo: Why does Saturn have a halo?
About the earth satellite
Artificial earth satellite refers to an unmanned spacecraft that flies around the earth and runs in space orbit for more than one circle. Satellite for short. Man-made satellite is the spacecraft with the largest number of launches, the widest use and the fastest development.
The earth has a gravitational effect on the surrounding objects, so the thrown objects will fall back to the ground. However, the higher the initial velocity, the farther the object will fly. When Newton thought about the law of universal gravitation, he imagined throwing objects from high mountains at different horizontal speeds, each time the speed was higher, and each time the landing point was farther from the foot of the mountain. If there is no air resistance, when the speed is high enough, the object will never land. It will revolve around the earth and become an artificial earth satellite orbiting the earth. Man-made satellite is the spacecraft with the largest number of launches, the widest use and the fastest development. 1957101On October 4th, the Soviet Union launched the world's first artificial satellite. Later, the United States, France and Japan also launched artificial satellites one after another. China launched the satellite Dongfanghong 1 on April 24th, 970. By the end of 1992, China has successfully launched 33 different types of satellites.