The most widely used positioning system today is GPS (Global Positioning System). The system is used so much that the word GPS has become synonymous with positioning. In this article we will briefly describe how GPS positioning works, and talk about two other positioning systems that exist today.
GPS is a system owned by the US Department of Defense, and consists of three parts: satellites, base stations and receivers. The satellites are in Earth's orbit and just like the stars we see in the sky every night, we can use mathematical calculations to know exactly where they are at a given time. The base stations secure the position of the satellites using radar. Finally, we have the receiver - it can be your mobile phone, the navigation system in your new Volvo or your GPS tracker from SweTrack. The receiver's task is to listen to signals from the satellites, and calculate the distance to the satellites. Once the receiver has calculated how far it is from a number of satellites, it knows exactly where you are on earth with just a few meters of precision. The recipient can then process this information and display it in a way that you easily understand - for example through the use of google maps, or in text form as coordinates (longitude, latitude). The GPS system covers every square meter of the earth's surface and works wherever you are in the world.
GLONASS: There is also a similar system run by the state in Russia, called GLONASS. GLONASS (Globalnaya navigatsionnaya sputnikovaya sistema, Глобальная навигационная спутниковая система) can be translated as "Global Navigation Satellite System" and consists of 20 satellites. GLONASS was developed in the Soviet Union in the 1970s and was originally only used for military purposes, but in 2007 the system was made available to ordinary citizens and can since be used in the same way as GPS. Both GPS and GLONASS cover the whole world - GPS is generally considered to provide better precision, but there are many indications that GLONASS provides marginally better precision in the northernmost parts of our planet.
Galileo: Recently another challenger has also emerged in the form of Galileo. Galileo was developed by the EU and is intended as an alternative to GPS and GLONASS. Galileo is believed to be able to provide slightly better precision than GPS in the long run.
BeiDou: China has its own system called BeiDou (BDS) (北斗 卫星 导航 系统). The latest satellite was launched on June 23, 2020 and has now global coverage.
There are two other systems that do not have global coverage, NavIC (Indian) and QZSS (Japanese). Unlike the other systems, these two have only regional coverage, and can therefore not be used worldwide.
In short: four different global positioning systems run by four different governmental organizations, but all four use basically the same way to calculate your position.