Military of China, force comment.
Military of China, force comment.

Data Figure: Russian GLONASS navigation satellites

News Background

According to the Russian Federal Space Agency Web site, Russia plans to launch nine satellites GLONASS global navigation system. Expected end of this year, GLONASS system, the total number of satellites in orbit will reach 24, that is, except that each orbital planes evenly seven working satellites, the orbital planes to add an in-orbit spare satellites, the signal range from expanded to cover the whole territory of Russia, global coverage. This will enable the interpretation of the GLONASS satellite navigation systems to improve the ground than in the past 30 to 40 percent accuracy, precision navigation signal also will increase nearly 2-fold. By then, GLONASS system and between the U.S. GPS system competition will become fiercer.

“polar bear” to grab the “cheese”

global communications, aerospace, exploration, rescue, national defense, security and other fields, are inseparable from satellite navigation system. The 1980s, this area has been monopolized by the U.S. GPS system. Russia willing to see such a large piece of “cheese” for a U.S. exclusive, in order to protect their own strategic interests, “polar bears” have begun to actively develop its own satellite navigation system.

GLONASS was developed by the separate deployment of the Russian satellite navigation system, the project started in the 1970s, this system requires at least 18 satellites to provide for the whole territory of the Russian satellite positioning and navigation services, such as to provide Global Services, you need 24 satellites in orbit. GLONASS satellite system to complete the deployment of all, its satellite navigation range can cover the entire Earth’s surface and near-Earth space, positioning accuracy to within 1.5 meters!

1.5 meters, which means that the Russian military’s precision-guided strike capability, will enter a horrible “pinpoint” era. Image point, said that Air Force fighters in the several tens of kilometers or even longer distances on the ground, a high-speed car for precise positioning, and launch missiles to destroy; naval vessels in the depth of a few hundred meters underwater launch strategy nuclear weapons, the use of GLONASS positioning system coordinates, precision strike the opponent’s strategic points (precision error of strategic nuclear attack is generally about 500 meters).

present, the Russian GLONASS satellite navigation system has 21 operational satellites, distributed in three orbital planes, as well as three backup satellites. Each satellite in a 19,100 km high orbit, the cycle is 11 hours and 15 minutes. GLONASS system has been running at reduced efficiency, is only 8 satellites to work, its low accuracy than the American GPS system. In recent years, Russia has actively embarked on GLONASS for technological transformation. Not long ago, they just launched three new “Tornado” satellite. The satellite’s design life will be 7 to 8 years (the current satellite life expectancy of three years), with better technical performance.

Although GLONASS and GPS satellite navigation system with the world, but they have many differences. GLONASS positioning accuracy, and GPS compared to a gap, but it has a stronger anti-interference ability. As the coordinates and the use of different standards on time, GLONASS, although in general international has its limitations, but in the vital strategic importance on the safety of life and death, this design avoids the enemy in wartime own satellite signal interference.

from the “two-fight” to “quarter of the world”

global satellite navigation system, known as “the eyes of humans in space.” Which country has this pair of “eyes”, like winning the space war mastered the “trump card.” Military needs and commercial interests should not be overlooked, so that the world in this area is becoming more competitive.

Currently, only four sets of the world’s satellite navigation system is working or development status of the U.S. GPS, Russia’s GLONASS, Europe’s “Galileo” and our “Big Dipper.”

GPS is the United States lasted 20 years, $ 20 billion satellite navigation system set up, its function is currently the most complete. In order to prevent “certain countries” to use the threat of the U.S. system, GPS systems provide only low accuracy on foreign satellite navigation signals. In the event of military conflict threaten its own security, the United States will immediately cut off the satellite navigation services. In order to prevent the United States led by the nose, the European Union in the late 1990s the decision: placement in space of their own “eyes” – “Galileo” system.

European “Galileo” system officially launched in 2002, the goal is to build a global coverage of satellite navigation systems, can provide the basic signals that the public can also provide the Government with a high degree of confidentiality of the signal, thus breaking the U.S. monopoly in this field. EU plans to invest for the more than 4.2 billion U.S. dollars, a total of 30 satellites launched. According to experts, once all 30 satellites in orbit, a higher accuracy than the GPS system.

the EU said, “Galileo” program will be strictly “limited civil” principle. The first satellite system is the Russian “alliance” rocket onto the space. As the “Galileo” program of the first non-EU partners, our commitment to the plans to invest 200 million euros.

as national security and the core of economic and social infrastructure, satellite navigation system must rely on other countries systems. China in 1994 and has begun to develop domestic satellite positioning system – “Compass.” According to experts, China’s satellite navigation system construction is divided into three steps. The first step, Compass, the system was completed and put into operation in 2003; the second step, Compass II regional system, launched in 2004, is expected to be completed in 2012; the third step, global coverage, high-precision Compass II global system, expected by 2020.

Compass system has been continuous and stable operation of more than six years in the army patrol, operational command, training exercises, disaster relief and other military activities play an important role. Especially the 2008 Wenchuan earthquake relief, Compass system to play its unique technical advantages. January 17, with 3 satellite was successfully launched, Compass II satellite navigation system into the acceleration phase network.

military experts predicted that the future satellite navigation systems in the near future would be “a quarter of the world.” However, we should clearly understand that: Compared with other countries, “Compass” navigation satellite system is still a long way to go, only to maintain its own expertise, while precise positioning coordinates and complete as soon as possible to improve anti-jamming capability to In the fierce competition in an invincible position.

who can grasp the advantages of satellite navigation, grasps the war initiative

in the defense, satellite navigation systems have become an information-based army, to fight won an important foundation of information warfare and assurance, in joint operations, battlefield situational awareness, precision strike, intelligence, reconnaissance, and played an irreplaceable role. The modern battlefield, equipped with satellite navigation systems are widely in combat vehicles, ships, aircraft, or even to use the level of company, platoon and even man, has become an integral part of combat and combat effectiveness of the multiplier.

United States, “Military Review” magazine has put it bluntly: “Who can grasp the advantages of satellite navigation, grasps the initiative in war.” Over the past 10 years, the United States have been able to play a very small cost of win many local wars, GPS support combat platforms and guided weapons played a significant role, no wonder that some U.S. military commanders issued a “No GPS, we can not fight” emotion.

no exaggeration to say, whether it is day, air, land or a joint operations command and control guidance and precision strike weapons guide, full of modern warfare on the battlefield without the “compass” – Satellite navigation systems. How to enhance the accuracy of satellite navigation systems and to prevent enemy interference, is the world next to in-depth study of important issues.

to ensure the leading position in the United States is planning the largest ever conducted on the GPS technology upgrades. Upgraded third-generation U.S. military global positioning system throughput is 500 times the current system, and anti-jamming capability will be greatly enhanced. In order to deal with more complex future battlefield environment, the EU countries are paying close attention to experimental design a new generation of satellite navigation, positioning accuracy will reach the “m” level.

Links

USA GPS: a receiver-based positioning system, only the broadcast signal, the receiver can locate the user, without capacity constraints. The entire system, including orbiting the Earth 24 satellites, each satellite can continuously transmit a certain frequency radio signals, as long as the signal reception held portable device, whether living on land, sea or air, can send specific signals received by satellite. Receivers selected in the computer as long as four or four or more satellite signals for analysis, the holder will be able to determine the location of receivers. In addition to GPS navigation but also have many other uses, such as scientists can use it to monitor crustal movement to help small earthquake prediction. But there are also GPS systems technical weaknesses. As each satellite signal frequency and modulation in the same way, different satellite signals by different pseudo-code to distinguish, with feedback to the ground from the GPS satellite signal is weak, if the other party to impose interference, is likely to ground receiving equipment does not work, leading to Navigation reduced accuracy.

Russian GLONASS: GPS works with basically the same. The difference is: GLONASS satellites distributed in three orbits, the more applicable to high-latitude users, and distribution of GPS satellites orbit in 6, compared to the middle and low latitudes user convenience. GLONASS single-point positioning accuracy of 16 meters horizontally, vertically 25 meters. Compared with the GPS, GLONASS positioning accuracy, invisibility, etc. at a disadvantage. The single point positioning accuracy for civilian (30 m) difference of about 20 meters with GPS; and “Galileo” system (civil signal accuracy of 1 meter) gap even greater. But the interference was significantly stronger than other systems, as by the GLONASS satellite frequencies to distinguish between different, more focused coverage of high latitudes, it can effectively prevent the rival satellite navigation system is interference.

European “Galileo”: EU plans to build a new generation of civilian global satellite navigation system. According to the plan, “Galileo” program will cost about $ 2.7 billion system of 30 satellites. Medium Earth orbit satellites used, evenly distributed in the height of about 2.3 million kilometers of three orbital planes, the work system, including 27 stars, plus three backup satellites. A typical system is the signal relay function, namely the user receiver data transfer is through a special contact or a relay system to achieve, for example through mobile communication network to achieve. “Galileo” system receiver can not only accept the signal, and can accept the GPS, GLONASS signals of these two systems, and mobile phones with navigation functions and capabilities are combined with other navigation systems, a combination of superior performance. (Jiang Heng)