Humankind has been figuring out ways to navigate for tens of thousands of years. For many generations in life, our ancestors used the stars to navigate. Not only did the sky help people pinpoint their location at open sea, but as many monuments today will attest, people of the past also used the stars as beacons to help them build geometrically accurate structures on land. Of course, today’s navigation tools are a lot more accurate, reliable, and easier to use overall. We have many satellites in space and systems like GPS and GLONASS to help us get accurate readings for exactly where we’re at in the world.
People in the surveying genre who use survey equipment might be very familiar with using satellite signals to help them get accurate readings. Though there is a bit of confusion about which is better, GPS or GLONASS, or even if there’s any difference between the two systems. So, to clear up this information, let’s go over some of the important details of these satellite systems below.
GPS vs. GLONASS: The Differences
Both of these systems are satellite-based navigation systems. The main difference is between nations. GPS, which stands for Global Positioning System, was developed by the United States and released in 1978. GLONASS stands for Global Navigation (translated from Russian) and was developed and released by the Soviet Union in 1982. While there are quite a few key differences, they’re basically set up to be the same positioning system that uses satellite signals.
The systems rely on microwave signals that are transmitted by their satellites in orbit around the Earth. The brilliant thing about these systems is how their satellites create a huge global network and transmit data at near lightspeed to any connected device on the planet, making it a boon for people using survey equipment. Though coming from two different nations and using two different sets of technologies, there are a few key differences in how they operate.
The first big difference one will notice between these systems is that they use a different number of satellites to build their network and to transmit their signals. The GPS uses 32 satellites and operates on six separate orbital planes, with an altitude of over 20,000 kilometres. This covers an incredibly broad range of territory, and it can give accurate measurements for practically any location on the planet.
The GLONASS system isn’t quite as vast as GPS. It uses 24 satellites and only three orbital levels, with an altitude of just over 19,000 feet. Even still, this is a large, accurate network that much of the world relies on for their navigation.
The second main difference is very complicated and based on mathematics. The transmission frequencies of GPS and GLONASS differ quite significantly. For GPS, these satellites transmit on an L1 band of 1575.42 MHz, while the GLONASS transmits on an L1 band of 1602 MHz. The Russian system makes up for its fewer number of satellites by having superior transmission technology.
The good news is that both of these systems’ L1 bands are for civilian use, so no matter where you’re at in the world, you can use whichever system you want to use and will not need special permission. They are always transmitting over these same frequencies and can be used.
What is Best to Use?
In terms of which system is better for surveyors, the differences in how they give actual positioning are almost non-existent. For instance, if you’re using a piece of equipment and are looking for positioning data with GPS, you won’t be receiving anything different than you would receive if you were using GLONASS and vice versa. In fact, the safest bet here might be to use a piece of equipment that’s tapped into both of these systems. There’s really no reason to choose, as you can use them both.
Hopefully, this clears up some important differences between these two popular systems. They work the same and perform the same tasks by and large, and either of them will help you with your tasks.