GPS, GLONASS, GALILEO navigation systems

Modern equipment uses not only GPS to determine our location, but also uses systems from other continents, such as the European Galileo system, the Chinese system Compass (the local name is Beidou, which means Big Dipper) or Russian GLONASS. In fact, we do not need to know about it, it is enough that the location option is activated and the rest takes place without our participation. Does this mean the GPS is too accurate? How will the war in Ukraine affect measurements? So let’s analyze the whole situation.

GPS it wasn’t really the first positioning system. It was Transit, built in the 1960s and originally used by the US Navy. GPS, i.e. Ppositioning She is his perfect successor. It was created in the 1970s and currently consists of 31 satellites that cover the entire globe. However, it has a huge downside. Despite its prevalence, it is still a military system. It’s up to the US military to decide how much accuracy it will offer. Thus, since May 1, 2000, we have witnessed the rise of universal access to digital maps and the possibility of localization. It was then that the US military made the precise targeting of civilian targets possible. Previously, the measurement error was 100m, which essentially disqualified GPS as a system for everyday use.

Besides the American solution, some of us have heard of the Soviet and now Russian system GLONASS. GLbalnaja ONVigacionnaja Sputnikovaya Sistiema was created in the second half of the 1970s in response to the development of American navigation. The target number of 24 satellites was reached in 1995. However, due to their short lifetime, only 3 years, and the crisis in Russia, only 6 satellites were in service at the end of the 1990s. Its functionality has began to increase at the beginning of the 21st century, when Vladimir Putin became interested in it, which was associated with the transfer of huge funds for the development of the system.

Although available to civilian users, its accuracy is not impressive. At best, it is around 2.8 meters, but it could well be more than 7 meters (it is not clear how much accuracy is offered for military purposes). GPS accuracy is 30 cm. However, some point out that GLONASS it defends itself in the higher latitudes of both hemispheres and in difficult terrain, for example, in the mountains (but here, in turn, the European system prevails, we will come back to this later), it still depends on many institutions providing laser measurements. This data makes it possible to accurately determine the orbit of the satellites. Poland has also provided such laser measurements (SLR, Satellite Laser Ranging) within the framework of the international organization ILRS (International Laser Ranging Service), which brings together several dozen stations, mostly European.

March 2 of this year Space Research Center of the Polish Academy of Sciences it stated on its website that it “stopped providing laser measurements on Russian GLONASS satellites”. The Center also encourages the signing of a cut-off petition GLONASS calibration systems. The same decision was taken by the Technical University of Munich (Technische Universität München, TUM), it completed the transfer of SLR data, which was collected in the EUROLAS Data Center (EDC). With this action, scientific institutions want to show that they only support the peaceful use of positioning.

Theoretically, contact with four satellites is necessary for the correct location of an object in space. In practice, receivers usually track at least five, as this will not interfere with location if the signal is lost. While calmly measuring on my smartphone, sitting at home, my phone picked up 8 satellites GPS9 GLONASS7 Galileo and 6 Compass.

As you can see, even a complete shutdown of the Russian system will not affect the measurements. In theory, Galileo alone would suffice. What is that? Galileo is the European navigation system launched relatively recently, in 2016, although its origins date back to the 1980s. It was created due to a lack of confidence in the American and Soviet military system, which can be disrupted at any time. Galileo is a civilian European Space Agency system, which means it should provide more stable operation. Ultimately, the accuracy of the system should be 1cm, although the current (i.e. available to everyone for free) aperture of 1m horizontally and vertically is sufficient for the exact location and is greater to the Russian system. It also offers greater precision and greater range, so that when entering, for example, a tunnel, we do not often lose range. In addition, location tests show that the GPS + Galileo combination performs much better in terms of location than GPS + GLONASS.

The European system also plays an invaluable role in the rescue through the service Galileo Search and Rescue. You can send an “SOS” signal from the sinking ship, and after a few minutes receive a response about the coming help. In a situation of danger, great emotions and nervousness, such information will certainly have a calming effect.

Although we continue to use the abbreviation GPS when we continue to think of location, it seems that the European satellite navigation system is taking the top spot. And in combination with GPS, the range and positioning quality are sufficient for everyday use.

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