The GLONASS Russian satellite system is designed to accurately determine the coordinates of an object located above the Earth's surface. Two other similar systems serve the same purposes: GPS (USA), Galileo (European Union). The group of GPS satellites first began to operate, then, in 1993, the Russian satellite system was officially put into operation. Now, as of the beginning of 2015, the signal from GLONASS satellites is confidently perceived anywhere in the world. The following is a comparison of two global navigation systems, Russian and American.
On the territory of the Russian Federation, it is permissible to use any of the indicated systems — GPS or GLONASS — for satellite control of vehicles. Moreover, the best accuracy of determining the coordinates will be obtained when using GPS and GLONASS signals simultaneously.
Navigation satellites of Russia and the USA
Applying each of the navigation systems individually, one can count on the following accuracy parameters:
- GPS (coordinates): with ground correction - less than 1 m, real accuracy - 2.6 m (satellites of the KA Bloc IIR model).
- GLONASS (coordinates): real accuracy - 5-10 m (Uragan-M satellites), for Uragan-K satellites the accuracy is 1-3 m, and with ground correction the average value is 4.5 m.
- GPS (speed): the error can be up to 10 m / s.
- GLONASS (speed): the error is up to 15 m / s (Hurricane satellites) or it does not exceed 0.05 m / s (Hurricane-M satellites).
Using the GLONASS system, transport monitoring is carried out according to the same algorithms as with any other similar systems. The receiver in the subscriber's device reads the coordinates, the control unit analyzes them and sends a message via the terrestrial communication channel (GSM / GPRS).
This is how satellite navigation works.
It is important to know that when a car “loses” a GSM base station, the satellite navigation algorithm ceases to function correctly.
The operator will see a fixed mark on the screen, but in reality the machine can be moved. Moreover, the control unit will be able to determine the coordinates of the satellites without errors. But the ability to send messages to the security system will be absent. If you need to perform real-time tracking, you must remember that satellite monitoring of vehicles cannot be carried out without the use of cellular communications.
Subscriber devices, GLONASS receivers
It is clear that any monitoring system will have maximum noise immunity and accuracy if the coordinates are determined in it using GPS and GLONASS satellites at the same time. The grouping of GPS satellites began to act earlier than others, and therefore, at first, the subscriber units received only the GPS signal. Then microcircuits appeared that correctly perceived signals from GLONASS satellites. In the third step, universal chips were introduced to the market, compatible with 2 or 3 information protocols at once.
Satellite Signal Receiver NV08C
Among domestic developments that meet the latest requirements, one can name the NV08C-MCM-M chip, manufactured since 2009.
Starline Universal Module
The owner of the Starline digital alarm system of any of the modern models has the right to purchase and install an additional GSM-communication module. This module is made in the form of a printed circuit board mounted inside the main unit.
Starline Modular Architecture
When the GSM module is installed in the main unit, in addition to the special connector, a navigation unit equipped with a GLONASS / GPS signal receiver is connected:
Starline Navigation Box
It is possible to carry out satellite monitoring of vehicles without using security functions. In such cases, more affordable equipment is suitable - the Starline M17 lighthouse, which tracks coordinates and speed.
Navigation Beacon Options
At the initial stage, the monitoring system can be built on the basis of the following equipment: navigation beacons, one cell phone and one computing device with Internet access. The phone is used to control beacons via SMS. But in reality, the lighthouse is a fairly primitive device, unable to track fuel level and some other parameters. Each such device can be replaced over time with more sophisticated equipment - a navigation terminal or a tachograph. So it will be possible to build, including an existing fuel control system.
Explanation of the concepts of terminal and tachograph
The functions of satellite monitoring of vehicles may include monitoring of the following parameters: battery charge, fuel level in the tank, etc. In addition to coordinates, all data can be read from the CAN bus. If you are not going to use the connection to the CAN bus, you can install additional sensors by connecting them to a single electronic unit. A navigation module can also be integrated into such a unit.
Tachograph with navigation, cargo vehicles
If the electronic unit can only “remember” the data, but not send it via the GSM channel, then the device is called a tachograph. A tachograph equipped with a valid GSM module is a terminal.
Any transport control system, if it uses terminals, can be supplemented with “panic buttons”. The driver presses the button, and the operator receives a message within 40 seconds.
Alarm button connection diagram
It is understood that vehicle tracking need not be carried out in real time. Data can simply be recorded and analyzed at the end of the day. But having an interactive mode has its advantages. One of them is indicated above (the ability to set the “alarm button”). The right to choose is best left to the owner.
It would seem that it is not so important which particular navigation system will be used - GLONASS or GPS.
The law requires trucks to install tachographs, but connecting these devices to the navigation module is not necessary. However, the continued development of the ERA-GLONASS program leads to certain thoughts. For a long time, including in our country, priority was given to navigation on GPS satellites. Now the situation has changed dramatically.
Features of GLONASS and GPS
The accuracy of determining coordinates using GLONASS satellites in 2015 will be doubled. Roughly speaking, the error value in most cases will drop to 1.4 meters.
Coordinate parameters received from the navigator
When less than 3 spacecraft remain in the range of the subscriber’s device, no navigation system can be used for its intended purpose. Therefore, it is better that a universal module that accepts GLONASS and GPS signals at the same time be mounted in the user equipment.
Any vehicle tracking system, if GSM is used in it, can determine the coordinates based on the signal of the base stations. True, the error in this case is 400-500 m.
The area of \u200b\u200bprobable location of the object
The mode in question is called “LBS”, and it is implemented in almost every GSM terminal. Thus, modern transport monitoring systems use data obtained from three sources of information:
- GPS signal;
- GLONASS signal;
- Radio waves coming from several GSM stations.
Positioning accuracy using global satellite navigation will increase almost every year. The error for the Russian system in 2020 will be 0.6 m. We can conclude that the use of satellite monitoring of vehicles in practice is a promising technology that will be in demand in the future. And everyone should be able to use new technologies correctly.
Tracking equipment and cheating methods
As a rule, the choice of a system responsible for tracking vehicles is a responsible process. Some motorists prefer GLONASS, others GPS. The developers of each of these systems provide their own algorithm for collecting and presenting data, are particularly accurate and reliable, as well as individual settings. Which system is better to choose will help determine our article, which will describe all the advantages and disadvantages of each of them.
As you know, today both our country, and the USA, and other states have satellites in orbit. These same devices are needed in order to determine the current coordinates of the car, observing from above. Naturally, a special device of a certain system must be installed on the machine. The more satellites a particular system has, the more accurately it can give coordinates.
What is a satellite system?
Any modern system, be it GLONASS or the same GPS, tries to determine the location of the object. Each system implies the presence of a special device, through which the location of the vehicle relative to the terrain is determined. This is a navigator, or rather, a navigation system that is built into the car. What does the navigator do? It interacts with satellites of the Earth’s orbit, where each of them gives the navigator an individual signal so that the device can distinguish one from the other. In order to more accurately determine three-dimensional spatial coordinates, a modern navigator needs to simultaneously receive data from four satellites.
To be more precise, the navigator must know the distance to these satellites in order to calculate its position. The default navigator is not an easy car instrument, but one of the segments of the space positioning system.
The devices in orbit are arranged according to a special scheme and it is called an almanac. Based on this very scheme, calculations are carried out. When the car moves, the coordinates of the navigator change all the time. To this end, the signal from the satellites is constantly updated and the distance is recalculated at certain intervals (a few seconds). All this gives the advantage to modern systems to track the movement of an object, in this case a car, calculating its speed and distance traveled.
It is not necessary to say that each car navigator, which is, holds in its memory an almanac even after turning it off. It is very convenient and every time he does not need to search for them again. In addition, if the device is used during the day, then the next link to the satellites takes place in a matter of seconds. “Hot start” - this is the name of this option, which is often advertised by manufacturers of navigators. If the navigator did not turn on for a long time, then binding to satellites will take longer (10-20 minutes) and the option will already be called a “cold start”.
So, GLONASS or GPS - which is better? Let's start with the history of systems and then consider their advantages and disadvantages.
Story
GPS arose almost immediately when the first satellite of the earth was launched, by the way the Soviet one. The Americans were the first to notice that the signal from the satellite changes as it moves. Thanks to this, it was possible to create a system that allows calculating the coordinates of not only the satellite, but also the object on the earth attached to it.
In 1964, the world's first TRANZIT navigation system began operating. They used it then only for military purposes. Using this navigation, military missiles were launched from submarines. But for civilian purposes, TRANZIT was completely unsuitable. The accuracy of the location of any object, also stationary, was limited to fifty meters. About moving objects and did not dream. In addition, the world's first navigator could not provide continuous determination of coordinates, since, being in low orbit, it was in sight from the Earth for only one hour.
Three years later, a new, more advanced satellite is launched. It was located in a higher orbit - Timation-1, and then launched the second Timation. These two satellites combined and created a system that is known as Navstar. Again, at first this system was used as a purely military one, and since 1993 it was allowed to make it completely free, aimed only at civilian needs.
Today, the Navstar system functions perfectly and consists of 32 satellites, among which 24 are considered the main ones. The orbital devices of the system provide full coverage of our planet, but just in case there are 8 more in reserve. GPS satellites move at a considerable distance from the earth in several orbits. A satellite completes a complete revolution around the Earth in almost the entire day.
Now about GLONASS. A system was created from the time of the USSR (no matter how short-sighted people abused this union, it is impossible to refute the fact of the state’s power). After the artificial Earth satellite was put into orbit, work began on the design of a positioning system.
The first navigation satellite from the territory of the Soviet Union was launched in 1967. It implied only one satellite for determining the coordinates, but subsequently a whole system was already created, which was equipped with receivers receiving the signal. It was not GLONASS yet. It was called Cicada (civilian version) and Cyclone (military version). The system was designed to determine the coordinates of objects in distress.
The GLONASS system itself was launched in 1982. It takes as long as 11 years and only after that the system is put into operation, after the collapse of the USSR. Twenty-four satellites, among which, due to the country's plight in terms of economy, some still do not work completely. It was this fact that determined in the 90s that the Russian system could not compete with the American system. Today, on the contrary, after the launch of the GNS target program, GLONASS is already considered as a direct competitor.
The GLONASS satellite constellation is a dual-purpose system, where, first of all, military objectives are set. Today 17 satellites are involved, which are located at an altitude of 19,100 km. The revolution around the planet is slightly faster than that of GPS satellites. GLONASS is constantly being modernized, and Russian developers have set a goal - to catch up with the Americans.
As it becomes clear, GLONASS historically lagged behind the American system. But over time, the gap has been narrowed. The era of the 90s negatively affected GLONASS, which was no longer needed, because it was raging in the country then. The system again falls into hibernation, from where it was gradually pulled out and modernized.
One head is good, and two is even better
Now about which is better to choose? Speaking directly, the average citizen of the country does not make any difference which system is used by his navigator. And you don’t even have to bother with this, as for both civilians, both satellites are equivalent. Both the American and Russian satellite systems can be used without restriction by a motorist. Access to GLONASS, in particular, is provided free of charge and without restrictions, however, as for GPS.
If we consider satellite systems from the point of view of the military or state sphere, then our shirt is closer to the body. At any moment, Americans are able to turn off the system, limiting it only to their army. This was already the case when the first war in Iraq was going on. And the authorities of our country directly oblige all civil servants to use their own navigation, while they only recommend the rest. Recently, even in the Duma they wanted to introduce a bill prohibiting the use of GPS in cars owned by government bodies.
On the other hand, the question remains: what system is more improved and better? It will be useful for Russians to know that the Swedish company of a nationwide satellite network has officially recognized the advantage of GLONASS, because in the latitudes where their country is located, the Russian system works more efficiently.
But, again, today any navigator or smartphone supports both GLONASS and GPS. Therefore, it would be more correct to ask the following question: which is better, GPS or GLONASS / GPS? The answer is unequivocal, of course, the second option is GPS / GLONASS satellite navigation, especially when it comes to location accuracy. But dual-system devices also have a minus - a high price, because they have two microchips installed. But the reliability of signal reception and the accuracy of determining coordinates are increased. Errors in longitude and width when determining the location of an object, if two-system navigation is used, is reduced to one and a half meters. For comparison, if the navigator operates only on GPS, the errors will average 4 meters. GLONASS - 6 meters.
Navigator selection
As mentioned above, today there are many domestic satellites, but there are more American ones. That is why most of the navigators work on GPS or they use the GPS / GLONASS system.
To determine your choice of navigator, you need to know that they are usually divided into three groups, depending on the scope and the services offered.
- Navigators for cars.
- Navigators for and.
- Universal travel navigators.
Our goal is to acquaint the reader with car navigators, which are the most popular in assortment and abundance.
The main task that a car navigator should solve is how to pave the way from one point to another. At the same time, maps, road signs, etc. must be involved. Below is a list of what a good navigator should have. Using it, you can choose a good and high-quality navigator.
- Powerful processor.
- Touch input support.
- The presence of voice prompts.
- Possibility to get traffic information.
- Opportunity .
- Necessary multimedia features.
Guided only by these parameters, choosing a navigator for your car will not be difficult. As for, as mentioned above, it is advisable to purchase devices that support both GLONASS and GPS.
Many car owners use navigators in their cars. However, some of them are not aware of the existence of two different satellite systems - the Russian GLONASS and the American GPS. From this article you will find out what their differences are and what preference should be given.
How the navigation system works
The navigation system is mainly used to determine the location of an object (in this case, a car) and its speed. Sometimes it is required to determine some other parameters, for example, altitude.
She calculates these parameters, setting the distance between the navigator itself and each of several satellites located in Earth orbit. As a rule, for efficient operation of the system, synchronization with four satellites is required. By changing these distances, it determines the coordinates of the object and other characteristics of the movement. GLONASS satellites are not synchronized with the rotation of the Earth, which ensures their stability over a long period of time.
Video: GLONASS vs GPS
What is better than GLONASS or GPS and what is their difference
Navigation systems primarily envisaged their use for military purposes, and only then became available to ordinary citizens. Obviously, the military needs to use the development of their state, because the foreign navigation system can be disabled by the authorities of this country in the event of a conflict. Moreover, in Russia they urge the use of the GLONASS system in everyday life by military and civil servants.
In everyday life, an ordinary motorist does not need to worry at all about the choice of a navigation system. And GLONASS, and provide quality navigation sufficient for use in everyday life. In the northern territories of Russia and other states located in the northern latitudes, GLONASS satellites work more efficiently due to the fact that their trajectories are higher above the Earth. That is, in the Arctic, in the Scandinavian countries, GLONASS is more effective and the Swedes recognized this in 2011. In other regions, GPS is a bit more accurate than GLONASS in positioning. According to the Russian system of differential correction and monitoring, GPS errors were from 2 to 8 meters, GLONASS errors from 4 to 8 meters. But GPS, to determine the location you need to catch from 6 to 11 satellites, GLONASS will have enough 6-7 satellites.
It should also be noted that the GPS system appeared 8 years earlier and went into a solid lead in the 90s. And over the past decade, GLONASS has reduced this gap almost completely, and by 2020, the developers promise that GLONASS will not be inferior to GPS in anything.
Most modern systems have a combined system that supports both the Russian satellite system and the American one. It is these devices that are the most accurate and have the lowest error in determining the coordinates of the car. The stability of received signals also increases, because such a device can “see” more satellites. On the other hand, the prices of such navigators are much higher than single-system counterparts. It is understandable - they incorporate two chips capable of receiving signals from each type of satellite.
Video: test of GPS and GPS + GLONASS receivers of Redpower CarPad3
Thus, the most accurate and reliable navigators are dual-system devices. However, their advantages are associated with one significant drawback - cost. Therefore, when choosing, you need to think - is such a high accuracy necessary in everyday use? Also, for a simple car enthusiast, it is not very important which navigation system to use - Russian or American. Neither GPS nor GLONASS will let you get lost and delivered to your desired destination.
Glonass-M spacecraft model at CeBIT 2011
"Glonass-M" (name for design and development work: Hurricane-MGRAU Index: 11F654M, 14F113) - a series of the 2nd generation GLONASS Russian global navigation system, developed and manufactured by JSC “ISS” named after academician M. F. Reshetnev. From the satellites of the Glonass series (1st generation) they differ in the guaranteed period of active existence (7 years). These emit, unlike the previous generation devices, already 2 signals for civil consumers, which can significantly improve the accuracy of positioning.
July 30, 2015 it was announced the completion of production of satellites of the Glonass-M series. They will be replaced by next-generation devices: Glonass-K and Glonass-K2.
Tactical and technical data
- weight - 1415 kg
- guaranteed period of active existence - 7 years,
- features - 2 signals for civilian consumers,
- in comparison with the satellites of the previous generation (Glonass), the accuracy of determining the location of objects is increased 2.5 times,
- bOT power - 1400 W,
- the beginning of flight tests - December 10, 2003.
- domestic on-board digital computer based on a microprocessor with a command system VAX 11/750 (K1839)
Accidents and incidents
- In July 2010, the train transporting in the Ulyanovsk region had an accident. The transported missile was intended to launch on September 2 from three Glonass-M navigation satellites.
- The launch of the Proton-M launch vehicle, carried out on December 5, 2010, at 15 hours 13 minutes (Moscow time) failed. After the launch, Proton-M changed its predetermined flight path, and even before separation it went off by a pitch of 8 degrees and the rocket went into open orbit. By the time of separation of the DM-3 (11С861-03) booster block with 3 GLONASS-M satellites, which had passed normally, it was already on an abnormal flight path, and then completely left the radio-visibility zone of Russian tracking equipment. Specialists never received telemetry from the upper stage after it was separated from the Proton. The remnants of the DM booster block with three Glonass-M satellites fell in the Pacific Ocean in the Hawaiian Islands. The total damage from the loss of satellites was estimated at $ 90 million, while only about thirty of the damage was covered by insurance - the insured amount was $ 3.5 million. Insurance company Sputnik Insurance Center dealt with insurance, the satellites were reinsured for $ 3.3 million. in the insurance company "Russian Insurance Center".
- July 2, 2013, the Proton-M booster rocket with the DM-03 (11С861-03) booster block and three Russian Glonass-M navigation spacecraft - "Hurricane-M" No. 48, "Hurricane-M" No. 49, "Hurricane-M" No. 50starting from Baikonur fell in the first minute of the start. None of the lost satellites was insured due to a shortage of funds allocated by Roscosmos for this article, and also because of the decision not to insure serial satellites.
GLONASS system
Global Navigation Satellite System (GLONASS) - Soviet / Russian satellite navigation system, developed by order of the USSR Ministry of Defense. One of the two global satellite navigation systems operating today (the Chinese Beidou satellite navigation system currently functions as a regional one).
GLONASS is intended for operational navigational and temporal support of an unlimited number of land, sea, air and space-based users. Access to GLONASS civil signals anywhere in the world, on the basis of a decree of the President of the Russian Federation, is provided to Russian and foreign consumers free of charge and without restrictions.
The basis of the system should be 24 satellites moving above the surface in three orbital planes with an inclination of the orbital planes of 64.8 ° and an orbit height of 19,400 km. The measurement principle is similar to the American navigation system. The main difference from the GPS system is that the GLONASS satellites in their orbital motion do not have resonance (synchronization) with the rotation of the Earth, which provides them with greater stability. Thus, the GLONASS spacecraft grouping does not require additional adjustments during the entire period of active existence. Nevertheless, the service life of GLONASS satellites is noticeably shorter.
Currently, the development of the GLONASS project is being carried out by Roscosmos and OJSC Russian Corporation of Rocket and Space Instrument Making and Information Systems. In order to ensure the commercialization and mass introduction of GLONASS technologies in Russia and abroad, in July 2009, by the Decree of the Government of the Russian Federation, a “Federal Network Operator in the Field of Navigation Activities” was created, the functions of which were assigned to Navigation and Information Systems OJSC. In 2012, the Non-Profit Partnership “Promoting the Development and Use of Navigation Technologies” was determined by the federal network operator in the field of navigation activities.
The history of development
Glonass-K model at CeBIT
Officially, the creation of GLONASS was launched in December 1976 by a special resolution of the CPSU Central Committee and the USSR Council of Ministers. This project was a continuation of the development of the domestic navigation satellite system launched by the Cyclone program.
The terms of work on the creation of the system were repeatedly shifted, the first flight tests were launched on October 12, 1982 by launching the first Hurricane 11F654 satellite and two mass-dimensional mock-ups 11F654GVM into orbit. In the next six launches, two regular vehicles and one prototype were launched into orbit. The use of layouts was a consequence of the unavailability of the electronic part of the satellites. Only on September 16, 1986, from the eighth launch in a row, three full-time devices were withdrawn at once. Two times in 1989, along with two Uragan satellites, the Etalon passive geodetic devices were put into orbit, which were used to refine the parameters of the gravitational field and its effect on the orbits of the Uragan spacecraft.
On April 4, 1991, GLONASS included two operable system satellites in two orbital planes at the same time, and on September 24, 1993 the system was officially put into operation by the Russian Ministry of Defense. In the same year, the United States launched the last 24th satellite into orbit (the first US satellite launched into orbit in 1974). After that, launches to the third orbital plane began to be carried out. On December 14, 1995, after the 27th launch of Proton-K with Hurricanes, the satellite constellation was deployed to a staff of 24 satellites.
In total, from October 1982 to December 1998, 74 Uragan spacecraft and 8 mass-dimensional models were put into orbit. During the deployment of the system 6 “Hurricanes” were lost due to failures of the 11С861 overclocking unit. According to estimates made in 1997, about $ 2.5 billion was spent on the deployment of GLONASS.
In the future, due to insufficient funding, as well as due to the short service life, the number of working satellites decreased to 6 by 2001.
In August 2001, the federal target program “Global Navigation System” was adopted, according to which the full coverage of the territory of Russia was planned in early 2008, and the system would have reached global scale by the beginning of 2010. To solve this problem, it was planned during 2007, 2008, and 2009 to launch six LV launches and put 18 satellites into orbit - thus, by the end of 2009, the constellation would again count 24 vehicles.
In 2002, a transition was made to the updated version of the geocentric coordinate system PZ-90 - PZ-90.02.
Since 2004, new Glonass-M spacecraft have been launched, which broadcast two civil signals at frequencies L1 and L2.
In 2007, the 1st phase of the modernization of the ground segment was carried out, as a result of which the accuracy of determining the coordinates increased. In the 2nd phase of the ground segment modernization, a new measuring system with high accuracy characteristics is installed at 7 points of the ground control complex. As a result, by the end of 2010, the accuracy of the calculation of ephemeris and departure of the onboard clock will increase, which will lead to an increase in the accuracy of navigation definitions.
At the end of March 2008, the Council of Chief Designers for the Russian Global Navigation Satellite System (GLONASS), which met at the Russian Research Institute of Space Instrumentation, slightly adjusted the terms for the deployment of the GLONASS space segment. Previous plans suggested that in Russia it would be possible to use the system by December 31, 2007; however, this required 18 operational satellites, some of which managed to work out their warranty resource and stopped working. Thus, although in 2007 the plan for launching GLONASS satellites was fulfilled (six vehicles entered orbit), the orbital constellation as of March 27, 2008 included only sixteen operational satellites. December 25, 2008 the number was brought to 18 satellites.
At the council of GLONASS chief designers, the system deployment plan was adjusted to ensure that the GLONASS system was operational in Russia at least by December 31, 2008. Previous plans included the launch into orbit of two triples of the new Glonass-M satellites in September and December 2008; however, in March 2008, the timing for the production of satellites and rockets was revised to bring all satellites into operation before the end of the year. It was assumed that the launches will take place two months earlier and the system will work by the end of the year in Russia. The plans were implemented on time.
On January 29, 2009, it was announced that Sochi would be the first city in the country where public transport in large numbers will be equipped with a GLONASS-based satellite monitoring system. At that time, GLONASS equipment manufactured by M2M Telematics was installed on 250 Sochi buses.
In November 2009, it was announced that the Ukrainian Research Institute of Radio Engineering Measurements (Kharkov) and the Russian Research Institute of Space Instrumentation (Moscow) will create a joint venture. The parties will create a satellite navigation system to serve consumers in the two countries. The project will use Ukrainian correction stations to clarify the coordinates of GLONASS systems.
On September 2, 2010, the total number of GLONASS satellites was brought to 26 - the constellation was fully deployed to fully cover the Earth.
In 2011, the ground control system was upgraded. The result of the modernization program was an increase in the accuracy of navigation definitions of the GLONASS system by 2-2.5 times, which is about 2.8 m for civilian consumers.
On February 26 of the same year, the first Glonass-K spacecraft was launched, which implements additional signals in the CDMA format and tests a new open signal in the L3 band.
From 2012 to 2020, 320 billion rubles were allocated from the budget of the Russian Federation for the development of GLONASC. During this period, it is planned to manufacture 15 Glonass-M satellites and 22 Glonass-K satellites.
In July 2012, a case was opened on the fact of unjustified spending and embezzlement of more than 6.5 billion rubles allocated for the development of the satellite system. On May 13, 2013, another criminal case was opened under the article “Particularly large-scale fraud” on the revealed fact of abuse of authority and theft of 85 million rubles.
In 2014, work began on ensuring the compatibility of the Russian and Chinese navigation systems GLONASS and Beidou.
On December 7, 2015, the completion of the GLONASS system was announced. The finished system was aimed at the final tests of the Ministry of Defense of the Russian Federation.
Navigation
GLONASS satellites are in medium-high circular orbit at an altitude of 19,400 km with an inclination of 64.8 ° and a period of 11 hours and 15 minutes. Such an orbit is optimal for use in high latitudes (northern and southern polar regions), where the GPS signal is poorly caught. The satellite constellation is deployed in three orbital planes, with 8 evenly distributed satellites in each. 24 satellites are needed to provide global coverage, while 18 satellites are needed to cover the territory of Russia. Signals are transmitted with a directivity of 38 ° using right circular polarization, power 316-500 watts (EIRP 25-27 dBW).
To determine the coordinates, the receiver must receive a signal from at least four satellites and calculate the distances to them. When using three satellites, the determination of coordinates is difficult due to errors caused by inaccurate receiver clocks.
Navigation signals
FDMA signals
Two types of navigation signals are used: open with normal accuracy and protected with increased accuracy.
The signals are transmitted by direct sequence spreading (DSSS) and modulation through binary phase shift keying (BPSK). All satellites use the same pseudo-random code sequence to transmit open signals, however, each satellite transmits at a different frequency using 15-channel frequency division (FDMA). The signal in the L1 band is located at the central frequency of 1602 MHz, and the transmission frequency of the satellites is determined by the formula 1602 MHz + n × 0.5625 MHz, where n this is the frequency channel number ( n\u003d −7, −6, −5, ... 0, ..., 6, earlier n\u003d 0, ..., 13). The signal in the L2 range is located at the center frequency of 1246 MHz, and the frequency of each channel is determined by the formula 1246 MHz + n× 0.4375 MHz. Opposite devices can not be simultaneously visible from the surface of the Earth, so 15 radio channels are enough for 24 satellites.
An open signal is generated by adding modulo 2 of three code sequences: a pseudo-random rangefinder code at a speed of 511 kbit / s, a navigation message at a speed of 50 bit / s, and a 100 Hz Manchester code. All of these sequences are generated by a single clock. The pseudo-random code is generated by a 9-step shift register with a period of 1 ms.
An open signal navigation message is broadcast continuously at a speed of 50 bit / s. A super-frame with a length of 7500 bits requires 150 seconds (2.5 minutes) to transmit a complete message and consists of 5 frames of 1500 bits (30 seconds). Each frame consists of 15 lines of 100 bits (2 seconds per transmission of each line), 85 bits (1.7 seconds) of data and checksums and 15 bits (0.3 seconds) for a time marker. Lines 1-4 contain direct information about the current satellite and are transmitted anew in each frame; data includes ephemeris, clock offsets, and satellite status. Lines 5-15 contain an almanac; in frames I-IV, data is transmitted to 5 satellites in each, and in frame V, to the remaining four satellites.
Ephemeris is updated every 30 minutes using measurements from the ground control segment; The ECEF (Earth Centered, Earth Fixed) coordinate system is used for position and speed, and acceleration parameters are also transmitted under the action of and. The almanac uses modified Kepler elements and is updated daily.
The high-precision protected signal is intended for authorized users, such as the Armed Forces of the Russian Federation. The signal is transmitted in quadrature modulation with an open signal at the same frequencies, but its pseudo-random code has ten times the transmission speed, which increases the accuracy of determining the coordinates. Although the protected signal is not encrypted, the format of its pseudo-random code and navigation messages is classified. According to researchers, the navigation message of the protected L1 signal is transmitted at a speed of 50 bits / s without using a Manchester code, a superframe consists of 72 frames of 500 bits in size, where each frame consists of 5 lines of 100 bits and takes 10 seconds to transmit. Thus, the entire navigation message has a length of 36,000 bits and requires 720 seconds (12 minutes) to transmit; it is assumed that additional information is used to increase the accuracy of the parameters of solar-lunar accelerations and to correct the frequency of clock generators.
CDMA signals
Since the mid-2000s, code-based GLONASS signals are being introduced.
The format and frequencies of the new signals are not finally defined. According to preliminary data from the developers, the GLONASS-K2 satellites will use three open and two encrypted signals in CDMA format.
The open L3OC signal is transmitted at a frequency of 1202.025 MHz, uses BPSK binary phase shift keying (10) for pilot and information signals; The pseudorandom rangefinder code is broadcast at a frequency of 10.23 million pulses (chips) per second and is modulated at the carrier frequency through QPSK quadrature phase shift keying, while the pilot and information signals are spaced apart by modulation quadrature: the information signal is in phase and the pilot signal is in quadrature. The information signal is additionally modulated with a 5-bit Barker code, and the pilot signal is modulated with a 10-bit Newman-Hoffman code.
The open L1OC signal and the protected L1SC signal are transmitted at a frequency of 1600.995 MHz, and the open L2OC signal and a protected L2SC signal are transmitted at a frequency of 1248.06 MHz, covering the range of FDMA signals. The open L1OC and L2OC signals use time division multiplexing to transmit pilot and information signals; BPSK (1) modulation is used for information and BOC (1,1) for pilot signals. Protected broadband signals L1SC and L2SC Template: Nei AI2 for pilot and information signals, and are transmitted in quadrature with respect to open signals; with this type of modulation, the power peak is shifted to the edges of the frequency range and the protected signal does not interfere with the open narrowband signal transmitted at the carrier frequency.
BOC modulation (binary offset carrier) is used in signals from Galileo systems and upgraded GPS; GLONASS and standard GPS signals use binary phase shift keying (BPSK), however both BPSK and QPSK are special cases of quadrature amplitude modulation (QAM-2 and QAM-4).
The navigation message of the L3OC signal is transmitted at a speed of 100 bps. One 1500-bit frame is transmitted in 15 seconds and includes 5 text lines, each 300 bits long (3 seconds). Each frame contains the ephemeris of the current satellite and part of the system almanac for the three satellites. A superframe consists of 8 frames and has a size of 12,000 bits, so it takes 120 seconds (2 minutes) to get an almanac for all 24 satellites. In the future, a superframe may be expanded to 10 frames or 15,000 bits (150 seconds or 2.5 minutes per transmission) to support 30 satellites. The system time is transmitted in each line. The UTC coordination second is taken into account by lengthening (filled with zeros) or shortening the last line of the month by one second (100 bits), the shortened lines are discarded by the receiver equipment.
| Modernization of the Glonass system | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| KA series | Year of deployment | Consists of | Stability of the hour | FDMA Signals | CDMA Signals | Compatible CDMA Signals | |||||
| 1602 + n × | 1246 + n × | 1600.995 MHz | 1248.06 MHz | 1202.025 MHz | 1575.42 MHz | 1207.14 MHz | 1176.45 MHz | ||||
| Glonass | 1982-2005 | Withdrawn operation |
5 · 10 −13 | L1OF, L1SF | L2SF | ||||||
| Glonass-M | 2003-2016 | In operation | 1 · 10 −13 | L1OF, L1SF | L2OF, L2SF | ||||||
| Glonass-K1 | 2011, 2014 | Flight Testing | 5 · 10 −14 | L1OF, L1SF | L2OF, L2SF | L3OC | |||||
| Glonass-K2 | after 2016 | In developing | 5 · 10 −14 | L1OF, L1SF | L2OF, L2SF | L1OC, L1SC | L2OC, L2SC | L3OC | |||
| Glonass | 2025 | On study stages |
L1OF, L1SF | L2OF, L2SF | L1OC, L1SC | L2OC, L2SC | L3OC, L3SC | L1OCM | L3OCM | L5OCM | |
| “O”: standard precision open signal / “S”: high precision encrypted signal “F”: frequency division multiplexing (FDMA) / “C”: code division multiplexing (CDMA) n \u003d −7, −6, −5, ..., 0, ..., 5.6. |
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Since 2014, it was planned to equip Glonass-M satellites with L3OC signal transmitters, first introduced in Glonass-K satellites, but these plans were not realized.
In the GLONASS-KM satellites, additional transmitters for frequencies and signal modulation can be introduced, coinciding with the modernized GPS (GPS modernization) and Galileo / Compass. In particular,
- the L1OCM signal will use BOC (1,1) modulation at a frequency of 1575.42 MHz, which coincides with the L1C signal of the upgraded GPS and the E1 signal of Galileo / Compass systems;
- the L3OCM signal will use BPSK modulation (10) at a frequency of 1207.14 MHz, which coincides with the E5b signal of Galileo / Compass systems;
- the L5OCM signal will use BPSK modulation (10) at a frequency of 1176.45 MHz, which coincides with the Safety of Life (L5) signal of the upgraded GPS and the Galileo signal E5a.
This configuration will help ensure broad compatibility of the receiving equipment and increase the accuracy and speed of determining coordinates for mission-critical applications, primarily in aviation and maritime security.
Technical means
NAP “GROT-M” (NIIKP, 2003), one of the first samples
The first receiver designed to work with American and Russian navigation systems was a professional Ashtech GG24 device, released in 1995.
The first consumer satellite navigator, designed for the joint use of GLONASS and GPS, went on sale December 27, 2007 - it was a Glospace satellite navigator. More than 10 enterprises produce navigation equipment in Russia.
In order to implement the Decree of the Government of the Russian Federation of August 25, 2008 No. 641 “On equipping vehicles, technical means and systems with GLONASS or GLONASS / GPS satellite navigation equipment”, NPO Progress has developed and launched GALS-M1 satellite navigation equipment, which many can already be equipped with today types of military and special equipment of the Armed forces of the Russian Federation.
In 2012, the Ministry of Transport of Russia determined the technical requirements for satellite navigation equipment to increase the safety of passenger transportation by road, as well as the transport of dangerous and special cargoes.
In May 2011, the first mass-produced GLONASS / GPS navigators from Explay and Lexand entered retail sales. They were assembled on the MSB2301 chipset of the Taiwanese company Mstar Semiconductor.
Today, models with GLONASS and GPS support are in the product lines of many manufacturers. The share of such devices in the total annual sales volume of navigators reaches 6.6% (for 8 months of 2011, about 100 thousand “dual-system” units were sold in Russia). A comparative test of the GLONASS / GPS navigator Lexand SG-555 and the Lexand ST-5350 HD GPS navigator was conducted by Vedomosti newspaper:
The test showed that for trips around Moscow you can get by with a single-system navigator. But the fact that the Glonass / GPS navigators work more accurately and more reliably has been confirmed in practice. The superior characteristics of dual-system devices are also relevant in everyday life - for example, if you want to change lanes in time to turn on the right lane.
Qualcomm, the American manufacturer of mobile chips, produces a family of chips for receiving GPS and GLONASS signals: Snapdragon 2 and 3. In 2011, the release of the Snapdragon 4 family was announced. Currently, the total number of models of devices with the possibility of receiving GLONASS is tens.
Accuracy
At present, the accuracy of determining coordinates by the GLONASS system is somewhat behind that of GPS.
According to the SDKMna September 18, 2012, errors in GLONASS navigation definitions (when p \u003d 0.95) in longitude and latitude were 3-6 m when using an average of 7-8 KA (depending on the point of reception). At the same time, GPS errors were 2-4 m when using an average of 6-11 KA (depending on the point of reception).
When using both navigation systems, a significant increase in accuracy occurs. The European project EGNOS, using the signals of both systems, gives the accuracy of determining coordinates in Europe at the level of 1.5-3 meters.
The GLONASS system determines the location of the object with an accuracy of 2.8 meters, but after the two satellites of the Luch system signal are put into operation, the accuracy of the GLONASS navigation signal will increase to one meter (previously the system determined the location of the object only to within 5 m).
By 2015, it is planned to increase positioning accuracy to 1.4 meters, by 2020 - to 0.6 meters with a further increase to 10 cm.
GLONASS-based high-precision positioning technologies are now widely used in various industries. So, the specialists of the Research Institute of Applied Telematics developed a unique solution for the navigation industry - a system for remote monitoring of the status of complex engineering objects, which in real time monitors the displacement of the road infrastructure and landslide geomasses (in post-processing with an accuracy of 4-5 mm), allowing only to respond promptly to the occurrence of emergency and emergency situations, but also to predict them in advance, timely determine the appearance of defects in road structures. The system was implemented and successfully tested on the section of the M27 federal highway Dzhubga-Sochi in the Khostinsky flyover area (section 194-196 km) - the most dangerous and complex in terms of structural strength.
Differential Correction Stations
Russia has begun work on locating stations of the differential correction and monitoring system to increase the accuracy and reliability of the GLONASS navigation system abroad. The first foreign station was built and successfully operates in Antarctica at Bellingshausen station. This provides the necessary conditions for continuous global monitoring of the navigation fields of GLONASS spacecraft. The current network of ground stations has 14 stations in Russia, one station in Antarctica and one in Brazil. The development of the system provides for the deployment of eight additional stations in Russia and several stations abroad (additional stations will be located in countries such as Cuba, Iran, Vietnam, Spain, Indonesia, Nicaragua Australia, two in Brazil, and one more will be located in Antarctica) .
Due to fears that GLONASS systems could be used for military purposes, the US State Department refused to issue Roscosmos permits to build several Russian measuring stations on American territory. The Act on the Actual Prohibition of the Location of GLONASS Stations in the United States was signed on December 30, 2013. In response to this, from June 1, 2014, work was stopped on the territory of the Russian Federation of stations for the GPS system. Apparently, this decision concerns 19 still operating IGS measuring stations in Russia. IGS stations are not designed for the operation of the GPS system itself and are more of a scientific value. In the United States, there are many similar stations transmitting GLONASS data in real time. The data of these stations are in the public domain.
Availability
The values \u200b\u200bof the positional geometric factor PDOP according to the GLONASS system on the earth's surface (elevation angle ≥ 5 °). Date: February 7, 2016
The GLONASS Information and Analytical Center publishes on its website official information on the availability of navigation services in the form of maps of instant and integral availability, and also allows you to calculate visibility zones for a given place and date. Operational and posterior monitoring of GPS and GLONASS systems is also carried out by the Russian system of differential correction and monitoring (SDKM).
It was officially predicted that GLONASS would catch GPS in accuracy by 2015, but according to official data for the first half of 2015, positioning accuracy was 2.7 m and the promise to double it was “postponed” to the end of 2015. However, as of February 7, 2016, even the official “accuracy forecast” indicated an accuracy of about 2-4 meters.
When using GLONASS and GPS together in joint receivers (almost all GLONASS receivers are joint), the accuracy of determining the coordinates is almost always excellent due to the large number of visible spacecraft and their good relative position.
According to Reuters, employees of the Swedish company Swepos, serving a nationwide network of satellite navigation stations, found that GLONASS provides more accurate positioning in the northern latitudes: “it works a little better in the northern latitudes because its satellite’s orbits are higher and we see them better,” than GPS satellites. " Jonsson said that 90% of his company's customers use GLONASS in combination with GPS.
The Decree of the Government of the Russian Federation of September 27, 2011 on the mandatory equipping of passenger vehicles with GLONASS / GPS modules forces the use of the GLONASS system in Russia.
Modernization
- In 2015-2017, it is planned to launch an advanced satellite of the Glonass-K2 spacecraft, finalized according to the test results of the Glonass-K1 spacecraft. In addition to the open CDMA signal in the L3 band, open and encrypted signals in the L1 and L2 bands will appear.
- By 2025, the improved Glonass-KM satellite will appear, the characteristics of which are under study; presumably, up to 6 open and up to 3 encrypted code division signals will be used in the new satellites.
- After a complete transition to CDMA signals, a gradual increase in the number of spacecraft in the group from 24 to 30 is expected, which may require disabling FDMA signals. We are considering options for launching additional satellites in the future in a highly elliptical orbit of the Lightning or Tundra type, or in a geosynchronous or geostationary orbit, which should provide higher availability in certain regions due to the differential correction of GLONASS signals from the main satellites.
Satellites
The developer and manufacturer of satellites is JSC ISS named after academician M. F. Reshetnev (until 2008 NPO PM) (Zheleznogorsk, Krasnoyarsk Territory).
Current state
- Total of the GLONASS OG: 28 KA
- Used for its intended purpose: 23 KA
- At the stage of entering the system: 0 KA
- Temporarily withdrawn for maintenance: 1 KA
- On the study of the chief designer: 2 KA
- Orbital reserve: 1 KA
- At the stage of flight tests: 1 KA
Satellite positioning and navigation systems, originally developed for military needs, have recently been widely used in the civilian sphere. GPS / GLONASS monitoring of vehicles, monitoring of people in need of care, monitoring the movements of employees, tracking animals, tracking luggage, surveying and cartography are the main directions of using satellite technologies.
Currently, there are two global satellite positioning systems created in the USA and the Russian Federation, and two regional, covering China, the EU countries and a number of countries in Europe and Asia. GLONASS monitoring and GPS monitoring are available in Russia.
GPS and GLONASS systems
GPS (Global Position System) is a satellite system, the development of which began in America since 1977. By 1993, the program had been launched, and by July 1995, they had achieved full system readiness. Currently, the GPS space network consists of 32 satellites: 24 primary, 6 backup. They revolve around the Earth in a medium-high orbit (20,180 km) in six planes, four main satellites in each.
On the ground, there is a main monitoring station and ten tracking stations, three of which transmit correction data to the latest generation satellites, and they distribute them to the entire network.
The development of the GLONASS system (Global Navigation Satellite System) began in the USSR in 1982. The completion of the work was announced in December 2015. GLONASS requires 24 satellites, 18 to cover the territory and the Russian Federation, and the total number of satellites currently in orbit (including backup) is 27. They also travel in a medium-high orbit, but at a lower altitude (19,140 km), in three planes, eight main satellites in each.
GLONASS ground stations are located in Russia (14), Antarctica and Brazil (one each), and a number of additional stations are planned to be deployed.
The predecessor of the GPS system was the Transit system, developed in 1964 to control the launch of missiles from submarines. She could determine the location of extremely motionless objects with an accuracy of 50 m, and the only satellite was in sight only one hour a day. The GPS program was previously called DNSS and NAVSTAR. In the USSR, the creation of a navigation satellite system has been carried out since 1967 as part of the Cyclone program.
The main differences between GLONASS monitoring systems from GPS:
- american satellites move synchronously with the Earth, and Russian satellites move asynchronously;
- different heights and number of orbits;
- different tilt angles (about 55 ° for GPS, 64.8 ° for GLONASS);
- different signal formats and operating frequencies.
- GPS - the oldest of the existing positioning systems, put in full readiness before the Russian.
- Reliability is due to the use of a larger number of backup satellites.
- Positioning occurs with a smaller error than GLONASS (on average 4 m, and for the latest generation satellites - 60–90 cm).
- Many devices support the system.
GPS Benefits
Advantages of the GLONASS system
- The position of asynchronous satellites in orbit is more stable, which facilitates their management. Regular adjustments are not required. This advantage is important for professionals, not consumers.
- The system was created in Russia, therefore, it provides reliable signal reception and positioning accuracy in northern latitudes. This is achieved due to the greater angle of inclination of satellite orbits.
- GLONASS is a domestic system, and will remain available to Russians in the event of GPS disconnection.
- Satellites rotate synchronously with the rotation of the Earth, therefore, for accurate positioning, the work of corrective stations is required.
- A low tilt angle does not provide a good signal and accurate positioning in the polar regions and high latitudes.
- The right to control the system belongs to the military, and they can distort the signal or disable GPS altogether for civilians or for other countries in case of conflict with them. Therefore, although GPS for transport is more accurate and more convenient, and GLONASS is more reliable.
- The development of the system began later and, until recently, was carried out with a significant lag behind the Americans (crisis, financial abuse, theft).
- Incomplete set of satellites. The service life of Russian satellites is shorter than that of American ones; they often need to be repaired; therefore, navigation accuracy is decreasing in a number of areas.
- Satellite monitoring of GLONASS vehicles is more expensive than GPS because of the high cost of devices adapted to work with the domestic positioning system.
- Lack of software for smartphones, PDAs. GLONASS modules designed for navigators. For compact portable devices, today the most common and affordable option is GPS-GLONASS support or only GPS.
GPS disadvantages
Disadvantages of the GLONASS system
Summary
GPS and GLONASS systems are complementary. The optimal solution is GPS-GLONASS monitoring. Devices with two systems, for example, GPS-markers with GLONASS-module “M-Plata” provide high positioning accuracy and reliable operation. If for positioning solely according to GLONASS the error is on average 6 m, and for GPS - 4 m, then when using two systems it is simultaneously reduced to 1.5 m. But such devices with two microchips are more expensive.
GLONASS is designed specifically for Russian latitudes and is potentially capable of providing high accuracy, because of its understaffing with satellites, a real advantage so far is on the GPS side. The advantages of the American system are the availability and a wide selection of devices with GPS support.
