Global positioning systems (GPS) have been helping us find our way for years. But what if the time comes when access to it becomes impossible for some reason? Or what if its GNSS constellation simulator stops working all of a sudden? Do we go back to printed maps and compasses, or ask the stars for guidance?
Fortunately, there exist a few alternatives to GPS navigation that are not as good but will help get you to your destination.
GLONASS
GLONASS is the acronym for Globalnaya Navigatsionnaya Sputnikovaya Sistema or Global Navigation Satellite System in English. Russians created this navigation system initially to measure velocity, timing, and weather positioning. Now, it is used just like the GPS—mainly for navigation.
The main differences between the two systems are the number of satellites and the communication between them and other receivers. While the GPS uses 32 satellites in six orbital planes, the GLONASS uses 24 in three orbital planes. It means that there are four satellites in every orbital plane for GPS and eight for GLONASS. The planes in the former system are unevenly spaced by 60 degrees while the GLONASS planes are evenly spaced by 120 degrees.
The other difference lies in the manner of communication of the satellites. GPS has different codes for each satellite and transmits with the same frequencies. GLONASS has the same code for each satellite but with varying frequencies.
In terms of accuracy, GPS seems to have a more accurate positioning globally, thanks to more ground stations. But in the northern hemisphere, or higher places, GLONASS is as, if not more, reliable than the GPS. Devices today use both navigational systems to enhance accuracy and provide users with an optimal experience.
Galileo
The European Union created the Galileo navigation system especially for European users and services. According to the European Global Navigation Satellite Systems Agency, Galileo can provide more precise positioning and timing information than GPS and GLONASS in the local setting.
The system uses 22 evenly-spaced satellites in three orbital planes. Each plane holds six to eight satellites. Galileo uses different codes for each satellite but transmits with the same frequencies. While the system is still in its development and testing phase, Galileo promises to deliver several benefits such as:
- More accurate positioning and timing information for European services
- Better resistance to information jamming
- Emergency response service
- Open service that remains under civilian control
- Interoperability with GPS and GLONASS systems
Once fully operational, several devices, including Apple, Android, and Blackberry are expected to carry chips that are Galileo-compatible.
BeiDou
BeiDou is China’s answer to US’ GPS, Russia’s GLONASS, and EU’s Galileo. It was created initially for the Chinese military so that they don’t have to rely on the US’ navigation system. Now, the system has also taken the commercial route, making its way into the transport, agriculture, and precision missile industries. In August 2018, thousands of taxicabs in mainland China were ordered to install BeiDou. Chinese mobile devices are also BeiDou-ready.
BeiDou currently has about 15 operational satellites servicing China and other parts of Asia. In 2020, the system is expected to have 35 satellites. When this happens, BeiDou will have the most number of satellites among all the global navigation satellite systems.
The future of navigation looks good, with all these GPS alternatives. The more satellites and ground stations these systems have, and the more interoperable they become, the more precise our positioning information will be.