3/18/2009

China's lack of high-precision satellite technology space rescue teams need to build

Two sessions on the national, aerospace industry representatives proposed to set up the application of satellite-based space-based emergency rescue systems. This is commonly known as the "space rescue team," the formation of the system will be the country's economic construction and military applications have a significant impact.
For ordinary people, the space-based emergency rescue system, the word sounds a bit hard to pronounce. Put it in simple language that this is a satellite orbiting spacecraft consisting of a large area to deal with natural disasters, systems engineering, which is formed by the Disaster Mitigation and Relief emergency satellite system.
200 million U.S. dollars of the satellite can restore loss of two billion U.S. dollars
Oriental Outlook reports, for disaster mitigation and relief, the satellite can be resolved is as nothing more than some aspects: early warning, to determine the scope and location of the affected areas to assess the severity of the disaster, positioning, communications contact, the timely release of information. It is now commonly used in remote sensing satellites, meteorological satellites, communication satellites, audio and video broadcast satellites, communications satellites and positioning satellite transit, disaster relief that can be used.
Since the satellite into space, humanity has been trying for the adoption of this technology to reduce the harmful effects of natural disasters. Job is now in almost all of the various satellites can be used in disaster mitigation and relief. To military applications such as the original positioning satellite based on a variety of natural disasters have played a positive role - Wenchuan earthquake, the Chinese self-developed Beidou Positioning System has been widely applied.
Another example, meteorological satellite is known as one of mitigation satellite. Since April 1, 1960 the United States successfully launched its first test since the Exploitation of Meteorological Satellites, a variety of adverse natural climatic disasters, the threat to humans has been much lower. Over the past 30 years, meteorological satellite successfully found every time the formation of a typhoon eye, and give timely warning, which the world's coastal areas to restore economic losses can hardly be estimated.
Space experts, Chinese Academy of Space Technology researcher Hao Pang said: "The United States weather satellites in each of the manufacturing and launch costs about 200 million U.S. dollars, but their whole life to restore economic losses more than 2 billion U.S. dollars. Investments into the middle class are the Exploitation of Meteorological Satellites than the very high investment projects an astronaut. "
Remote sensing satellites for disaster mitigation and relief work is also very great role. Disaster occurred at the early stage of remote sensing satellites through optical aerial photography or radar radiation, detect in advance the arrival of disasters and early warning in disaster after the disaster area can also be observed to determine the area affected as well as specific sites for the decision-makers to make reaction. Now China and the international disaster reduction on a dedicated satellite is mainly composed by the remote sensing satellite system.
Dangerous navigation
At the beginning of satellite development, mankind realized the tremendous advantages of space vehicles. Before there is no satellite, communications, broadcast television signals, the positioning system mainly based on the ground, such as deep into the underground communication cable, fiber optic cable, wireless base stations and so on. The event of earthquakes, floods and other natural disasters, the system relies on ground stations at the scope of the disaster area will all be facing paralysis. If there are no satellites assist, to command the ground or air power to enter the disaster site, it is necessary to re-establish a temporary ground support systems, or air systems. Otherwise, the complexity in the environment and weather of the disaster area, it is difficult to communication, let alone command coordination.
Satellite positioning system is a major advantage in the United States GPS satellite positioning system widely used before, the positioning is still mainly rely on inertial navigation, magnetic navigation, the terrain than for navigation, navigation Stars.
At seismic sudden natural disasters, etc., due to mutations in geomorphology geomagnetic anomaly, it is difficult to use than topography and geomagnetic navigation.
Inertial navigation in the emergence of satellite navigation are aircraft had been the main means of navigation, but with the increase in distance will produce the error stack effect - the former Soviet Union had been shot down over Korea Flight 007, that is, because of inertial navigation error, deviation from the route nearly a thousand kilometers, before straying into the restricted area was shot down. This is not a reliable means of navigation, satellite navigation is now used primarily as a supplementary means of existence.
Stars used mainly for navigation and early operations at sea, the sea surface because there is no landmark available for observation, so often will make use of the constellation navigator projected their own position in which latitude and longitude - but because of the use of complex and accuracy is not high, is now rarely使用.
Wenchuan earthquake in this situation, is indeed a difficult position faced by the grassroots units of the important challenges. Because a lot of troops into the disaster areas are non-local troops on the local geographical environment does not know. The earthquake has caused the river diversions and deformation of the mountain, the original map is basically the loss of a role. Watch the situation from the scene, where the allocation has Beidou Positioning System or GPS units, are often faster and be able to implement the rescue arrived at the designated locations.
International Disaster Monitoring Constellation in "Beijing One"
Space-based emergency rescue system is not a new concept, as early as July 1999, held in Vienna, Austria UNISPACE III meeting, the European Space Agency and the French Space Agency on the establishment of a set of agreed upon to deal with natural disasters, international space coordination mechanism, and to be known as "Space and Major Disasters The International Charter", in October 20, 2000 with the Canadian Space Agency signed the charter. Nowadays already have, including China, more than 10 countries and regions add.
The Charter provides for the first time, countries in the event of natural disasters, have an obligation to other signatory countries to provide resources to assist the satellite data. Wenchuan earthquake, the National Disaster Reduction Center of China through the "Space and Major Disasters The International Charter" as a mechanism to obtain from Japan, the United States, Nigeria, the United Kingdom, France, Germany, Canada, 7 of the National Space Agency satellite remote sensing images.
Apart from international cooperation mechanisms, in 2003 by the British company Surrey Satellite Technology initiated by the International Disaster Monitoring Constellation also officially put into operation, the Constellation is the world's first dedicated to the global disaster monitoring constellation of satellites. At present, there are five satellites in orbit, all in accordance with the uniform technical standards for design and production, but because of the different firing order of a slightly different. One of China in Beijing on the 1st satellite launched in 2005, is the constellation of stars in the fourth job is also to date the highest-resolution optical one, the United States and Europe developed their own disaster monitoring satellite systems.
China's lack of high-precision satellite technology
Although the Chinese aerospace industry has developed rapidly in recent years, but still with the world advanced level in the gap must exist.
Hao Pang, said the biggest difference between China and developed countries, mainly in the satellite technology on communications satellites. China's current communication satellites can only achieve with a fixed ground terminals of the call, even once Aerospace Exhibition in Zhuhai mobile display system, it was the installation of the software and automatically Starchaser Starchaser base vehicle platform only technically speaking, and not much different from the fixed communication stations, and the so-called mobile communication is only relative, if not too fast or traffic signals may be lost.
So far no similar Chinese Iridium system or the international maritime satellite communication system for a class of hand-held mobile terminals. Although such systems on weekdays because of the use of the high cost of application is not high, but once a disaster has happened is a very important means of communication. Especially in Wenchuan after the earthquake, the ground all communications interrupted, if the quake-hit area still retains a certain number of satellite communications equipment, while still with the district units on contact. Regrettably, however, this preparation is not sufficient, districts and counties a lot of long lost contact with the outside world.
China's satellite communications system is not only short-board. As a developing country, although China has a relatively complete industrial system space, but there are still too small quantity, quality problem. Before the earthquake in Wenchuan, China does not have exclusive use of remote sensing satellites for disaster reduction. September 6, 2008 the first group of optical remote sensing satellite was put into use for Disaster Reduction, which has been in the scheme of the radar stars have not yet been put into use. Vis-à-vis foreign countries has been used less than 1-meter resolution remote sensing satellite, China's lack of such precision satellite technology.
China's existing Beidou Positioning System at Wenchuan earthquake Although the application of good, but not without flaws. The system is now only two satellite positioning can only be carried out two-dimensional spatial orientation, that is, the altitude are not informed of the Beidou system.
The two sessions aerospace sector raised by space-based emergency rescue system, obviously does not refer to a specific hardware device, but rather refers to the comprehensive development of communication, positioning, remote sensing satellite technology, and through resource integration and the new mechanism set up , so that Chinese space technology in disaster mitigation will play a greater role.
NPC deputies and CPPCC members put forward the idea, is likely to be based on existing emergency response mechanism of reflection. Our country apart from the exclusive use of satellites for disaster reduction is still developing, the associated management mechanisms are still in perfect ripe. Now domestic civil aspects of satellite imagery resources are mainly from the Chinese Academy of Sciences, Ministry of Land and Resources and the Ministry of Civil Affairs, and many other units deal with separately, although the natural disasters will eventually aggregate information to the Ministry of Civil Affairs Office for Disaster Reduction, but the flow is not yet fully sorted out.
Learn from the system point of view, the "space-based emergency rescue system" should not be only a few satellites, or certain kinds of technology, but in the event of sudden natural disasters can immediately form a complete satellite control centers, and timely treatment , analysis, and convey information both at home and abroad related to satellite data.

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