Kiko Tue Mar 21, 2023 7:30 pm
China will add reliability to Russian space, by Mikhail Kotov for VZGLYAD. 03.21.2023.
Russian satellite navigation will receive support from China.
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 interaction between Russia and China, which appear during the visit of the Chinese leader to Moscow.
The Russian government 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 the practical interaction between Russia and China in the field of satellite navigation, to ensure the 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 geopositioning (in this case, the Russian GLONASS system) on Earth, work has only just begun. It just seems that satellites work independently in space, and those who use the constellation can only relax and only receive a signal. In fact, the ground services responsible for the functioning of the group are constantly working to ensure that the coordinates are determined as accurately and quickly as possible.
GLONASS satellites operate at an altitude of 19,400 kilometers. At the same time, the orbit of spacecraft is optimized for use at high latitudes of the planet, that is, where the territory of the Russian Federation is located. Under normal conditions (in open areas) from anywhere in Russia, the device must see at least four spacecraft to determine its exact coordinates (three signals provide accurate triangulation, the fourth is a control one and helps determine the height above sea level).
How does this happen? Spacecraft transmit signals that are received by a chip inside your smartphone and thereby allows you to determine its (and, accordingly, your) location. The chip measures the time it takes the signal to reach the device.
Knowing the positional point of each of the spacecraft of the navigation system, this method can determine its exact location.
The problem is that even at such a high altitude, spacecraft are gradually but inexorably changing their position in orbit. This is due to many factors, including, for example, the solar wind.
The change relative to the circumference of the orbit is almost imperceptible, but it can make its own adjustments to the determination of the location. Therefore, the ground services of each of the satellite navigation systems are constantly working to determine the exact coordinates of each satellite and enter 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 the almanac for all spacecraft in its constellation. This data is valid for several months and is intended to provide a rough indication of which spacecraft are currently overhead. And so that the search for satellites and obtaining information does not have to be started anew each time with its constant use and when moving a few meters, there are so-called hot start systems.
In addition, each spacecraft transmits with a signal to the user its own and only its own ephemeris - data that contains the most accurate corrections of the orbit parameters for each device. It is they who provide the maximum accuracy of determining your location.
Surely you have noticed that sometimes in the first seconds the smartphone determines the location less accurately. This is due to the fact that the chip has not yet received ephemeris from the satellite, they are sent to users every half a 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 another option for obtaining ephemeris via the Internet, the so-called hot start system (A-GPS), this is the general name for such systems, regardless of the grouping.
That is, there is a lot of work on Earth. And this work really greatly affects the usability of the navigation system.
In the event of the start of work on cooperation in the field of satellite navigation, Russia and China will begin to exchange information on refining the orbits of spacecraft. Perhaps the parties will start creating programs to increase the accuracy of determining coordinates. In recent years, Russia has already carried out such a program on its own - and some improvements have been achieved. Together with China, such work will be even more effective. Probably, it will be possible to increase the accuracy of navigation even more.
Yes, modern chips use data from all the spacecraft that the satellite sees - both the American GPS and the 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 crazy, 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 to expand cooperation in the international program COSPAS-SARSAT, the international satellite search and rescue system. In case of emergencies on ships and aircraft, it announces the distress and the location of personal radio beacons installed on vehicles. GLONASS satellites are also part of this system, which has already saved more than tens of thousands of lives.
Either way, working together is good. Especially when it is carried out on an equal footing, and in this type of cooperation, this is undoubtedly true.