Beidou satellite navigation system foundation part 1

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One 、 Why should China develop Beidou satellite navigation system ？

Speaking of Beidou , Most people are no stranger , At present, Beidou navigation has been applied to every aspect of people's life , In car navigation 、 Shared bike location 、 Aerospace science and technology 、 Military science and technology have been widely used . In earthquake relief 、 search for and rescue 、 It plays an irreplaceable role in medical work . Because of the Beidou , Our life is more convenient . Then under the conditions at that time , Why do you want to develop your own Beidou satellite navigation system ？ Let's briefly review .

1、 External environmental factors

1） The gulf war

1991 The Gulf War that broke out in taught the world a lesson , It also shocked us , The war could have been fought like this , Precision guided American equipment is as easy as chopping melons and vegetables in the face of tens of thousands of Soviet armor in Iraq , We finally understand that we should not develop satellite navigation , Whether tragedy will happen to us is still unknown , At this time, the old beauty GPS The system has been put into use , The satellite navigation system of the former Soviet Union has also been basically completed , This makes our country realize that we must have our own satellite navigation and positioning system .

2） Galaxy event

1993 year , A Chinese ocean going ship “ Galaxy ” The freighter was shut down by the Americans GPS, Lost its way in the boundless sea , And the positioning system of the search and rescue ship we sent was abnormal , Very passive , This makes our country realize that if we completely rely on GPS Will be shut down 、 Disturbed , More extreme is being falsely GPS Signal deception , Light car 、 The ship went the wrong way , The most important thing is that the missile attacks the wrong target , You may hit yourself , because GPS It belongs to the US air force , This system includes military code and civil code , Almost all moving objects that can fly are used by the US Army GPS, And the civilian side , If you leave GPS, The mobile phone can't navigate , Stock trading time cannot be synchronized accurately , It is difficult to map and locate super large projects such as bridges , Precision agriculture 、 Automatic driving has also become empty talk , This has strengthened our determination to independently develop satellite navigation .

2、 Start Beidou construction

1994 year , China has started the construction of Beidou satellite navigation system , But it's hard to cook without rice , Independent research and development from scratch , The difficulty can be imagined , until 2000 year , China just launched its first Beidou satellite , At this time GPS It's operational 30 many years , Beidou is not even a scum in front of it , At this rate, let alone catch up , Want to see GPS I don't know how long it takes to realize the taillights , Just at this time, the European Galileo navigation system extended an olive branch to us , We threw ourselves into 2.7 USD billion to participate in Galileo Project , And then Europe went to do something very excessive , Only accept our funds , We are not allowed to participate in the research and development of core technologies , In a fit of rage , We began to work hard , It's just 2020 year 6 month 23 Xichang Satellite Launch Center successfully launched the Beidou satellite navigation system No 55 star , It is also the last navigation satellite , This marks the completion of the launch of all Beidou navigation system global networking satellites , Here 26 On the way to tackle tough problems in , A series of fruitful results have been achieved , Here we should thank those scientists who have paid for it , So far , More than half of the countries in the world have started to use Beidou , Beidou has surpassed... In technology GPS, But the commercial road of Beidou has just begun , Need more external support .

3、 The significance of developing Beidou

from 1994 Beidou-1 system project was approved in , Up to now, the beidou-3 networking satellite launch mission has ended , Chinese Beidou people have gone from “ To chase after ” To “ Head up and lead the race ”, from “ Disciplined by others ” To “ Self control ”, from “ Regional services ” To “ Global directions ” The arduous course of . Now , The deployment of the global satellite navigation system constellation has been completed , The Chinese people have finally ushered in this highlight moment of their dreams . Beidou satellite navigation system can meet the needs of public security and economic and social development , Provide continuous services for global users 、 Stable 、 Reliable service ; It can also develop the satellite navigation industry , Serve economic and social development and improve people's livelihood ; Let's talk more about , Can deepen international cooperation , Share the achievements of satellite navigation development , Improve the comprehensive application benefit of global satellite navigation system .

Two 、 What is Beidou satellite navigation system ？

1、 summary

China Beidou satellite navigation system （Beidou Navigation Satellite System, BDS） It is a global satellite navigation system developed by China , Following the US global positioning system （GPS）、 Russian GLONASS satellite navigation system （GLONASS） After that, the third mature satellite navigation system . Beidou navigation system （BDS）、 The United States GPS、 Russia GLONASS And the European Union GALILEO It is a supplier recognized by the United Nations satellite navigation Committee .

2、 Basic composition

Beidou satellite navigation system consists of space segment 、 The ground segment and user segment are composed of three parts , Can be around the world 、 All day to provide all kinds of users with high precision 、 Highly reliable positioning 、 Navigation and time service , And has short message communication 、 Navigation 、 Positioning and timing capabilities , The positioning accuracy is divided into meter 、 Centimeter level , Speed measurement accuracy 0.2 rice / second , Timing accuracy 10 nanosecond .
1） Space segment ： The Beidou space segment consists of several geostationary satellites 、 Tilted geosynchronous orbit satellite and medium circular earth orbit satellite, etc .
2） Ground segment ： The ground section of Beidou system includes the master control station 、 Time synchronization / Several ground stations, such as injection stations and monitoring stations , And inter satellite link operation management facilities .
3） User segment ： The user segment of Beidou system includes chips compatible with other satellite navigation systems 、 modular 、 Antenna and other basic products , And end products 、 Application system and application service, etc .

3、 Development features

Construction practice of Beidou system , Out of the rapid formation of service capacity in the region 、 Gradually expand the development path with Chinese characteristics to serve the world , It has enriched the development model of the world's satellite navigation industry . Beidou system has the following characteristics ：
1） The space segment of Beidou system adopts a hybrid constellation composed of three kinds of orbital satellites , Compared with other satellite navigation systems, there are more high orbit satellites , Strong anti blocking ability , Especially in low latitudes, the performance advantage is more obvious ;
2） Beidou system provides navigation signals of multiple frequency points , It can improve the service accuracy through the combination of multi frequency signals .
3） Beidou system innovation integrates navigation and communication capabilities , With positioning, navigation and timing 、 Star based enhancements 、 Foundation strengthening 、 Precise point positioning 、 Short message communication, international search and rescue and other service capabilities .