Is it possible to disconnect Russian residents from global satellite navigation systems? How to ensure the success of Russian technologies in such a sensitive area? The answer to this question is provided by documents on new forms of practical cooperation between Russia and China, appearing during the visit of the Chinese leader to Moscow. The Russian government has instructed Roscosmos, together with the Russian Foreign Ministry, to coordinate with China the creation of a subcommittee on cooperation in the field of satellite navigation.
The document signed by Prime Minister Mikhail Mishustin has been published on the legal information portal. [...]
According to the document, it is proposed to strengthen practical cooperation between Russia and China in the field of satellite navigation, to ensure compatibility and complementarity of the Russian GLONASS and the Chinese Beidou system. Why is this necessary and how useful is such work for Russia?
Oddly enough, but since the launch of spacecraft for global geo–positioning (in this case, the Russian GLONASS system), work has just begun on Earth. It only seems that satellites work independently in space, and those who use the grouping can relax and only receive a signal. In fact, the ground services responsible for the functioning of the grouping are constantly working to ensure that the coordinates are determined as accurately and quickly as possible.
GLONASS spacecraft operate at an altitude of 19,400 kilometers. At the same time, the orbit of the spacecraft is optimized for use in the high latitudes of the planet, that is, where the territory of the Russian Federation is mainly located. Under normal conditions (in an open area), the device should see at least four spacecraft from anywhere in Russia to determine its exact coordinates (three signals give an accurate triangulation, the fourth is a control one and helps determine the altitude above sea level).
How does this happen? Spacecraft transmit signals that are received by the chip inside your smartphone and thereby allows you to determine its (and, accordingly, your) location. The chip measures the time it took for the signal to reach the device.
Knowing the position point of each of the spacecraft navigation system, this method can determine its exact location.
The problem is that even at such a high altitude, spacecraft gradually but inexorably change their location in orbit. This is due to many factors, including, for example, solar wind.
The change relative to the orbit circumference is almost imperceptible, but it can make its own adjustments to the location determination. Therefore, the ground services of each of the satellite navigation systems are constantly working to determine the exact coordinates of each satellite and make these changes.
There are two types of information about the location of spacecraft in orbit – almanac and ephemeris. The almanac contains the parameters of the orbits of all satellites, and each satellite transmits an almanac for all spacecraft of its grouping. This data is valid for several months and is intended to roughly determine which of the spacecraft are above the user's head at the moment. And so that the search for satellites and obtaining information does not have to start anew every time with constant use and when moving a few meters, there are so-called hot start systems.
In addition, each spacecraft transmits its own and only its own ephemerides with a signal to the user – data that contains the most accurate adjustments of the orbit parameters for each device. It is they who ensure the maximum accuracy of determining your location.
Surely you have noticed that sometimes in the first seconds the smartphone detects the location less accurately. This is due to the fact that the chip has not yet received ephemerides from the satellite, they are sent to users every half minute. As soon as the chip receives this information and makes corrections, the accuracy of determining the coordinates increases to a couple of meters. There is also an option for obtaining ephemerides over the Internet, the so-called hot start system (A-GPS), this is the common name for such systems, regardless of the grouping.
That is, there is a lot of work on the Ground. And this work really greatly affects the usability of the navigation system.
In the event of the start of cooperation in the field of satellite navigation, Russia and China will begin to exchange information on the refinement of spacecraft orbits. Perhaps the parties will start creating programs to increase the accuracy of determining coordinates. In recent years, Russia has already conducted such a program on its own – and managed to achieve certain improvements. Together with China, such work will be even more effective. It will probably be possible to further increase the accuracy of navigation.
Yes, modern chips use data from all spacecraft that the satellite sees – both American GPS and European Galileo. Nevertheless, the accurate and uninterrupted operation of its system is one of the most important conditions for national security.
In the summer of 2022, voices were already heard with ideas to "disconnect" Russia from the GPS global navigation system.
The ideas themselves are delusional, but the general direction of thoughts is clear. In this situation, it is critically important for Russia to independently maintain the performance of GLONASS at the maximum level.
Partnership work on an equal footing with China is also a very good help in this story. Unification of signals, joint testing of systems. In addition, two systems in the event of some serious opposition are always better than one, more reliable.
A separate conversation is the work on expanding cooperation in the international COSPAS–SARSAT program, the international satellite search and rescue system. In case of emergency situations on ships and airplanes, it notifies about the disaster and the location of personal beacons installed on vehicles. GLONASS satellites are also part of this system, which has saved more than a dozen thousand lives.
In any case, working together is good. Especially when it is carried out on equal terms, and in this type of cooperation, this is undoubtedly the case.
Mikhail Kotov
