北斗简述（Beidou briefly）

北斗简述（Beidou briefly） 北斗简述(Beidou briefly) The navigation system In the area of satellite navigation technology, the current U.S. GPS and Europe's Galileo system have 30 satellites. As developed by our country a global satellite positioning and communication system, the beidou satellite navigation system is the U.S. global positioning system (GPS) and the third after Russia's GLONASS satellite navigation system of maturity. The system consists of three parts: the space end, the ground end and the client. The space end includes five geostationary orbit satellites and 30 non-stationary orbiting satellites. Now China has sent 16 navigation satellites and four experimental satellites into space, and 40 more satellites will be added to the system in the next 10 years. The client consists of a beidou user terminal and a terminal that is compatible with other satellite navigation systems such as GPS, GLONASS, and the European Union, GALILEO. [1] 1. Coverage: the beidou navigation system is a regional navigation system covering China. Range of about 70 ? east longitude 140 ?, 5 ? 55 ? north latitude. GPS is a global all-weather navigation system. To ensure that six to nine satellites can be observed at any time and at any time on earth (in fact, up to 11). 2, satellite Numbers and orbital characteristics: beidou navigation system is set up on the earth's equator plane 2 geostationary satellite satellite about 60 ? Angle from the equator. GPS is in 6 set 24 satellites orbit plane orbit 55 ? inclination of the equator, orbital plane Angle of 60 ? the equator. The satellite will orbit the earth at an average of 11 hours and 58 minutes a week. Location principle: the beidou navigation system is an active, two-way navigation. The ground center control system is solved for the user to locate the data in three dimensions. GPS is the passive pseudo - code - directional range - based 3d navigation. The 3d positioning data of the user is independently solved by the user device. The principle of "beidou" number one brings two problems, one is the user to locate the lost the concealment of the radio at the same time, it will be very bad on the military, on the other hand, the equipment must include the transmitter, so on the size, weight, price and power at a disadvantage. 4. Positioning accuracy: the 3d positioning accuracy of beidou navigation system is about a few tens of meters, and the timing accuracy is about 100ns. The GPS 3d positioning accuracy P code is now increased from 16m to 6m, and C/A code is now increased from 25-100m to 12m, which is about 20ns before the time of insemination. 5, user capacity: the beidou navigation system because it is the active two-way ranging inquiries - response system, between the user equipment and geostationary satellites not only ask signal receiving ground center control system, also requires a user equipment to the synchronous satellite launch response signal, so that the user of the system capacity depends on the channel user allow model.next, ask signal rate and frequency of the user's response. Therefore, the user device capacity of the beidou navigation system is limited. GPS is a one-way distance measurement system, and the user's equipment can be located by the navigation satellite sent by the navigation satellite, so the capacity of the user device of GPS is unlimited. 6, viability, and all the navigation and positioning satellite systems, "beidou no. 1" based on centralized control system and satellite work, but the "beidou no. 1" on the dependence of the center control system are much bigger, Because the location solution is there and it's not done by the user device. In order to compensate for this system vulnerability, GPS is developing the interplanetary data link technology to enable GPS satellites to operate independently if the main control station is destroyed. The "beidou no. 1" system, in addition to that possibility, could not continue to work once the central control system was damaged. 7, real-time, "beidou" number one user for back to the center positioning control system, center control system solution to calculate the three-dimensional position of the user data and then back to the user, which passes through walking back and forth a geostationary satellite, plus satellite forward, center control system, the processing of time delay is longer, so for the movement of body, increases the positioning error. In addition, the "beidou 1" satellite navigation system has some features of its own: 1. "beidou" has a dual role of location and communication, and the ability of SMS communication is not available in GPS. 2. The positioning accuracy of "beidou" is one point two meters. The "beidou" terminal costs about 20,000 yuan. 4. No base station is required to be installed in the receiving terminal. The ship of the disaster center can send out information in a second. 7 correlation Although GPS has been widely used, it's not perfect. 1. Its size and cost are too high, and it is difficult for other countries to follow suit. The Russian and European space stations are typical examples. 2. GPS can only be used as navigation but can't realize the communication function, so it cannot meet the growing demand of users. If you rely on GPS alone, you can easily be controlled by others. "?? Satellite positioning system, the application business in this area has just begun, and some trials of civilian trials have been carried out for more than one year. "Beidou no. 1" and GPS difference mainly lies in two aspects, on the one hand is the difference between the technical system, GPS positioning system is a receiving type, only broadcast signals, the user receives located can do, is not restricted by capacity. "Beidou 1" is a two-way street that has both location-based and communicative systems, but with limited capacity, GPS is a Shared system of military and civilian control by the U.S. military, and is open to the world. The GPS that we Chinese use is a signal that can receive it for free, but the americans don't promise to guarantee your use, he doesn't charge for it, but he doesn't promise to never charge for it. The GPS in the United States that year has just been used far more than the "beidou no. 1" expensive, early in the late 1980 s and early '90 s when people is using GPS system the cheapest GPS receiver will be tens of thousands of dollars, and expensive to hundreds of thousands of dollars, a set of two. The current user terminals of the beidou are more expensive than the low price of the GPS, and now the GPS price general navigation system is in the thousands of RMB, with a high accuracy of tens of thousands to tens of thousands of RMB. The user terminal of beidou is currently around 20,000 yuan. Another problem is that its use and features are different, and GPS solves a problem of where I'm located, such as in the desert, in the ocean. And the beidou not only solves the problem where I am, it also solves the problem where you are here, the user terminal of beidou actually has the transceiver function, And GPS only with functions of receiving, it only know by receiving position, the big dipper is sending and receiving function, its positioning need to launch and then get position, at the same time its location may be passed on to you can also to the people who care about you, big dipper is actually a double function positioning and communication equipment, is not the same as in the user base, receiving occasions are not the same. Beidou when argument in that year, the state seismological bureau an earthquake research institute researcher out a report of the argument is about this problem, the beidou system will become a lifeline engineering, is the human survival and activities related to some of the projects, such as earthquake, all of our cable system after the earthquake may lose function, the beidou system as a satellite monitoring system can have the location of the report in time, and can communicate, such as a tsunami, is actually caused by the earthquake, which is very useful to do the rescue, it can timely send location and relevant information related to the position, we can send the information to the relevant departments. Price problem, in fact, the price is related to the number of users, one thousand users and ten thousand, thousands of users, to the user terminal can have very different cost, the main cost is in the user terminal, beidou user terminal said just now is there is a hair have, with the development of the business users, the cost will be down. So the "beidou" is civilised. Beidou no. 1 "potential, mainly in the field of integrated positioning communication, the demand on the comprehensive function is will be fully in the field of application, now only positioning need to customers, to the needs of the big dipper is not urgent. But for the need to have both position and passed out the position of the user, the beidou satellite navigation and positioning system is very useful. Beidou positioning accuracy is equivalent to GPS, generally around 1.2m. At present, the beidou navigation system is open to use at home. China's beidou navigation system can be broadly divided into generation and generation. A generation of three satellites, consisting of two working stars and a backup star. On May 25, 2003 in xichang satellite launch center in China will be the third "beidou" navigation and positioning satellite into space, marked the our country have their own first generation satellite navigation and positioning system. The first two satellites were launched on 31 October 2000 and 21 December 2000 respectively. The beidou satellite navigation and positioning system is the first regional navigation system that provides satellite navigation information throughout the day. Stage 2: [1] On April 14, 2007, China successfully launched the first beidou navigation satellite. [2] On April 15, 2009, at 01616 hours, China successfully launched the 2nd beidou navigation satellite into orbit by using the "long March 3 c" carrier rocket at xichang satellite launch center China's satellite navigation engineering center controller introduces, the launch of the BeiDou navigation satellite (COMPASS - G2), is China's BeiDou satellite navigation system (COMPASS, Chinese transliteration name BeiDou) construction plan of the second network satellite, is geostationary satellites in orbit the earth. The successful launch of the satellite, It is of great significance for the construction of beidou satellite navigation system. Satellite navigation system is an important space infrastructure, which can provide high precision positioning, speed measurement and timing service, which can bring huge social and economic benefits. China attaches great importance to the construction of satellite navigation system, and has been striving to explore and develop the satellite navigation system with independent intellectual property rights. China's completed beidou navigation system has played an important role in mapping, telecommunications, water conservancy, transport, fishing, exploration, forest fire prevention and national security. At present, the construction of beidou satellite navigation system is being implemented. The satellite and launch vehicles were developed by the China space technology research institute and the China academy of launch vehicle technology, which is owned by China aerospace science and technology corporation. It was the 116th flight of the long march series of carrier rockets. [3] On January 17, 2010, 0 12 points, xichang satellite launch center in China with the "long March 3 c rocket, success will be the third beidou navigation satellite into orbit, it marks the beidou satellite navigation system construction is an important step, satellite network is steady progress as planned. According to China's satellite navigation engineering center controller introduces, our country is implementing the BeiDou satellite navigation system (COMPASS, the Chinese name for the BeiDou) construction, planning and long-range launch 5 geostationary orbit satellites and 30 non stationary orbit satellite, and build global coverage of the BeiDou satellite navigation system. Previously, two beidou navigation satellites have been successfully launched, which is a stationary orbit satellite. In accordance with the construction plan, the beidou satellite navigation system will first provide navigation, timing and short message communication services in the asia-pacific region at the beginning of 2012. Around 2020, the global beidou satellite navigation system will be built. [fourth] Beijing time on June 2, 2010 on the evening of 23 53 points, in xichang satellite launch center in China with the "long March 3 c rocket, will be the fourth beidou navigation satellite into space orbit successfully, it marks the beidou satellite navigation system network construction is an important step. The fourth beidou navigation satellite and carrier rocket "long March 3 c", respectively, by the China aerospace science and technology group co., LTD belongs to China academy of space technology and the China academy of launch vehicle technology development, the satellite launch is China's "long march" series of carrier rocket 124th space flight. [the fifth] China successfully launched the fifth beidou navigation satellite in the xichang satellite launch center with a long March 3 carrier rocket at the xichang satellite launch center in Beijing on Aug. 1, 2010. [sixth] Beijing time on November 1, 2010, 10 with 26 points, xichang satellite launch center in China with the "long March 3 c rocket, success will be the sixth beidou navigation satellite into space, this is our country this year continuous network satellite launch of the fourth beidou navigation system. [seventh] At 4:20 a.m. on December 18, 2010, China successfully launched the seventh beidou navigation satellite in xichang, the 136th flight of the long march series. So far, China has completed 15 space launches this year, including chang 'e-2. A record high. [eighth] Beijing time on April 10th, 2011, 4 when 47 points in xichang satellite launch center in China with the "long March 3 armour" carrier rocket, success will be the eighth beidou navigation satellite into space is scheduled to transfer orbit. The launch is this year the first launch of beidou satellite navigation system networking, is the first space launch for China's "twelfth five-year" period, marked the basic system of a regional satellite navigation system is built, in the history of China's independent satellite navigation system development is of great significance, marks the beidou system construction and application into a new stage of development, has had a profound impact on development of China's satellite navigation cause. At 4:47 PM on April 10, China launched its eighth beidou navigation satellite into orbit on a "long March 3" launch vehicle at xichang satellite launch center. This is a tilt geostationary satellite. [9] Beijing time on July 27, 2011, 44 points, 5 in xichang satellite launch center in China with the "long March 3 armour" carrier rocket, success will be the ninth beidou navigation satellite into space is scheduled to transfer orbit, this is the network of the fourth beidou navigation system tilt the earth synchronous orbit satellite. The successful launch of the beidou navigation satellite marks a solid step in the construction of the satellite navigation system in beidou region. The successful launch of the beidou navigation satellite marks a solid step in the construction of the satellite navigation system in beidou region. At present, beidou satellite navigation system of the basic system has been completed, is rushing to develop the star alignment and testing of the evaluation work, a preliminary testing system, will be the end of the year early for most of our country and the surrounding areas to provide continuous passive location, navigation and timing, and short message communication service, meet the transportation, fishery, forestry, meteorology, telecommunications, water conservancy, surveying and mapping industry, and the application of the public user needs. In accordance with the "three-step" development strategy, the end of next year, our country will also have more network navigation satellite launch, improve system performance, to expand coverage, complete the construction of a regional satellite navigation system. By 2020, the beidou global satellite navigation system, consisting of more than 30 satellites, will provide high-precision, high-reliable positioning, navigation and timing services to the world. The satellites and rockets were developed by the China space technology research institute and the China academy of launch vehicle technology, which is owned by China aerospace science and technology corporation. It was the 141st flight of the long march series carrier rocket. 8 complete networking China launches the beidou ii satellite, which can avoid electromagnetic interference attacks and locate accurate to cm According to the national space administration, China succeeded in sending the second beidou navigation satellite (beidou 2) into a predetermined orbit at the xichang satellite launch center on April 15. According to the head of the China satellite navigation engineering center, the beidou ii satellite is a geostationary stationary orbit satellite that can provide positioning, speed and timing services for China and its surrounding areas. Compared with the "beidou 1", which is still in operation, the "beidou ii" has advantages in many aspects, including the ability to effectively avoid electromagnetic interference and attacks to realize passive location. In terms of accuracy, the precision of "beidou 1" is within 10 meters, while the "beidou 2" can be accurate to "centimeter". , said an official with the China aerospace science and technology corporation, which is related with the satellite launch is successful, China's beidou satellite navigation system from this year into the network peak, around the year 2020 is expected to form a global satellite navigation and positioning system. Several satellites will be launched this year, complete system networking within three years, and have basic operational capabilities. On this basis, it will gradually develop into a global service. China has launched three "beidou navigation satellite" satellites since 2000 and has built a test system. In the 2008 wenchuan earthquake, the system played an important role in navigation and positioning. The second generation of the beidou satellite navigation system is currently under construction. The first satellite was launched in April 2007. The satellite launched yesterday is the second satellite of the system. 9 satellite navigation The beidou satellite navigation system consists of four (two working satellites, two standby satellites), the beidou positioning satellite, ground control center, and the beidou user terminal. China's beidou navigation system and U.S. GPS, Russian gronas, and the European Union Galileo system are known as the world's four largest satellite navigation systems. At present, the United Nations has identified the four systems as the core supplier of the global satellite navigation system. The beidou allusions are introduced Also known as the "big dipper". Seven bright stars arranged in a bucket (or scoop) in the north. They are: the armature, the sky, the heaven, the heaven, the jade, the sun, the light. The first four stars consist of a bucket, called a kui or a kui. After that, the samsung consists of a bucket handle, called a scoop or bucket, also known as a jade balance. The beidou is different in different seasons and at different times in the night, and it appears in different directions of the sky. The ancients used to determine the season according to the direction of the daze, and the handle was in the east. In the south, all summer; In the west, the world is autumn; The handle is in the north, the whole world is winter. The ancients were used to the position of the beidou. "Chu ci.9 song.dongjun" : "in the arc of gymnastics, the anti-falling, the aid of the beidou." GuanShu shiji. Day ":" the big dipper, the so-called 'spin, ji, jade scale to seven government.' "syma researches now:" the spring and autumn yun dou shu "cloud:", the first day of pivot, second, third ji, the fourth and fifth scale, the sixth mizar, seventh wave light. The first to fourth chief, 5 to 7 as the standard, and to fight. '" Wen Yao hook "cloud;' bucket, the tongue of the day. Jade is a scoop of equilibrium, chief for CV 21. '" 10 navigation system The beidou ii needs to launch 35 satellites According to the plan, the beidou satellite navigation and positioning system will consist of five geostationary satellites and 30 non-stationary orbit satellites, using the dongfanghong 3 satellite platform. 30 non stationary orbit satellite is subdivided into 27 in orbit (MEO) satellites and three tilt synchronization IGSO satellites, 27 MEO satellite evenly on the Angle of 55 degrees of three planes, altitude 21500 kilometers. The beidou satellite navigation and positioning system will provide open service and authorization services. Open service provides location, speed and timing services in the service area. The positioning accuracy is 10 meters, the accuracy of the timing is 50 nanoseconds, the speed accuracy is 0.2 meters per second. Authorization service is for military purposes of ma3 jia3, will provide authorized users with more security and higher precision of positioning, velocity and timing services, plus inherited from beidou communication service function of test system. 10.2 precision performance of beidou ii Satellite signals are stronger than existing GPS Beidou satellite navigation and positioning system of the basic is completed by 27 MEO satellite positioning, through three 55 ? inclination of the orbit plane a deployment nine moons, position precision can reach within 10 meters, 7.5 meters accuracy theory can achieve the horizontal and vertical direction, the beidou system although the imitations of GPS system, but according to MEO 2007-1 satellite launch foreign technical staff for the determination of the signal, after the beidou satellite navigation and positioning system at B1 frequencies higher than GPS 7 dB, fully embodies the advantage of backwardness, before the new GPS III system deployment, the performance of the beidou satellite navigation and positioning system is much more outstanding. Improved navigation accuracy in China and surrounding areas The 5 stationary orbiting satellites not only provide RNSS services, but also inherit the RDSS signal link of the test system and retain the short message communication function. In order to improve the positioning accuracy satisfy aviation type I precision approach (CAT 1) requirement, the GEO satellite is used for precision is enhanced in our country, five GEO satellite can completely meet the accuracy requirement, and its surrounding areas of the CAT - 1 to 4.4 ~ 7.7 m vertical positioning performance, can satisfy the survey of land and resources in high-density visible stars without base level 1 meter real-time positioning accuracy requirements, after the completion of the beidou satellite navigation system to achieve the performance, the performance of the big dipper will surpass the existing GPSII system, even more than some areas of GPS system enhanced performance. China's beidou navigation system has been extensively covered in southeast Asia, and according to a recent report from China's ministry of science and technology, Laos and brunei will adopt the beidou navigation system through research and cooperation agreements. In early April, Thailand signed a similar agreement with China to become the first overseas client of China's homegrown navigation system. Currently, the beidou satellite system has covered southeast Asia and aims to cover the world by 2020. Improved navigation accuracy in high latitudes In order to meet the demand of signal enhancement in high latitudes, three IGSO orbital satellites have been added. IGSO satellites height and stationary orbit satellite is the same, but the Angle is not zero, so the orbit center set on the longitude of the equator, under the star point north and south, back and forth movement on the ground, an obvious figure 8. IGSO orbital satellites have overcome the problem of low elevation of GEO satellites in high latitudes and can signal enhancement to high latitudes. 3 IGSO satellites orbit the north to 55 ? north latitude, but the precision of the territory of our country effectively enhanced. The first purpose of satellite navigation is for military service, even for GPS. From the formation of the type 094 nuclear submarine, the 5IGSO and even 7IGSO satellites have been demonstrated at home, which will increase the scope of the country's strategic nuclear weapon system to meet the requirements of the strategic nuclear weapon system. Another way of thinking about the north push is similar to that of Japan's quasi-zenith Satellite System, which is not in sync orbit. The eight - shape deformation can be greatly improved, and the signal positioning of the smaller satellites will enhance the performance. The beidou second-generation navigation system still retains a generation of short message communication functions, which GPS doesn't have, which can play a key role in emergency disaster relief.