GLONASS – The GPS Alternative You Never Knew Existed
Did you know there’s more to location services than GPS? There’s another satellite navigation system which you might not have heard of, but you’re probably already using. It’s called GLONASS.
What is GLONASS?
An acronym for Globalnaya Navigatsionnaya Sputnikovaya Sistema (Global Navigation Satellite System), GLONASS is a Russian Aerospace Defense Force-operated satellite-based navigation system that is very much like GPS . While GPS came first, created by the United States Army in 1978, GLONASS was intended as an alternative system.
Contemporary uses for GLONASS are the same as GPS, with it being primarily used as a system for vehicle and aviation navigation. Historically, however, it was used in all branches of Russia’s military as a navigation system in high-speed scenarios, such as in jet planes and ballistic missiles.
Development for GLONASS first began in the late 1970s, when the first system was released. It was used mainly for weather positioning, velocity measuring, and timing, and was available throughout the world. However, with the fall of the Soviet Union, funding was scaled back and it wasn’t fully completed. Paired with the short lifespan (about three years) of the satellites, few people believed in the success of the GLONASS program. It wasn’t until 2001, when Russia’s president Vladimir Putin declared completing it to be a top government priority and massively increased funding did it become regarded as a serious technological institution.
In 2007, Putin issued a Decree of the President of the Russian Federation, opening GLONASS up for unrestricted public use. This was an attempt to garner public and industry interest, and to challenge the homogeny of the American GPS system. By 2010, GLONASS achieved complete coverage of Russia’s territory. One year later, thanks to its orbital satellite constellation, it achieved global coverage.
How Does It Work?
There are three components to GLONASS. The first is the space infrastructure, which consists of the satellite constellation. This is a group of satellites working together in a system. These are usually set up in orbital planes, or paths, around the earth along which they orbit.
These work with ground networks, which augment the accuracy and speed of the satellites by feeding back geodesic information. Ground location networks are ideally spread evenly throughout the world, allowing for even system availability and accuracy. However, with GLONASS, ground location networks are located mostly in Russia, Antarctica, Brazil, and Cuba. Russia has also agreed to open ground stations in China, which would see it become a viable competitor to GPS in one of the fastest growing consumer electronics markets in the world. In addition, GLONASS has been slated to open an additional seven ground stations in 2014. These would all be located outside of Russia.
These triangulate the location of the receiver, the third part. This is any device that is compatible with GLONASS, such as a smartphone or a vehicle navigation system.
Triangulation is done through a series of calculations based upon the contents of the signals sent out by the satellites. These are sent at precise intervals. Any receiver on or near the earth using GLONASS to position itself will use the signals from at least four satellites to estimate position, velocity, and time.
Guy McDowdell explained triangulation (or trilateralization) has been explained in greater detail in his article “How Do Satellites Track Mobile Phones? “.
GLONASS first used the FDMA (Frequency Division Multiple Access Method) channel access method to communicate with satellites, with 25 channels for 24 satellites. This is a popular protocol used in satellite communications, but has the disadvantage of crosstalk causing interference and disruption.
Since 2008, GLONASS has used CDMA (Code Division Multiple Access Technique ) in order to allow compatibility with GPS satellites. Because GLONASS receivers are compatible with both FDMA and CDMA, they are both larger and more expensive.
What Makes It Different From GPS?
There are some significant differences between GLONASS and GPS.
For one, GLONASS has fewer satellites in its constellation. GPS has 32 which circle the globe in 6 orbital planes, or paths of orbit. GLONASS has 24 satellites with 3 orbital planes. This means that with GLONASS, more satellites follow the same orbital path. For systems using GLONASS only, it may be more difficult to connect to available satellites. This could potentially lead to reduced positioning accuracy.
The biggest difference between GPS and GLONASS is how they communicate with receivers. With GPS, satellites use the same radio frequencies but have different codes for communication. With GLONASS, satellites have the same codes but use unique frequencies. This allows satellites to communicate with one another despite being in the same orbital plane, whereas this is not as much of a problem with GPS.
But How Accurate Is It?
GLONASS’s accuracy is comparable to GPS. But this was not always the case. At the beginning of the 21st century, GLONASS was falling into disrepair, and the satellites were approaching the end of their short life spans. The system barely functioned.
As a result, Roscosmos (The Russian Space Agency) set a target for GLONASS to match GPS in terms of accuracy and reliability by 2011.
By the end of 2011, GLONASS had met its goal. It was shown to be accurate in the absolute best environment (no cloud coverage, tall buildings or radio interference), to 2.8 meters. This made it slightly less accurate than GPS, but perfectly acceptable for most military and commercial use cases.
The accuracy of GLONASS varies depending upon where you are. It’s more accurate in the Northern Hemisphere than in the Southern Hemisphere due to the higher prevelence of ground stations in these parts.
Is It As Widely Used As GPS?
Although many handset manufacturers include GLONASS chips in their devices, such as Sony, Apple, and HTC, it is nowhere near as common as GPS, which is included in the majority of smartphones and tablets released today.
This is partly due to is being more accurate in Northern latitudes, as it was intended mainly for Russia, compared with GPS which has a more global approach.
The low awareness of GLONASS can also be attributed to it being significantly less mature than GPS andvirtually no GLONASS-exclusive devices being released outside of the former Soviet Union.
How Can I Use It?
Depending on the manufacturer of your smartphone, you may already have a GLONASS chip in your device. iPhones and a significant amount of Android devices use both GLONASS and GPS to ensure optimal accuracy.
If you are stuck in an area with a large amount of cloud coverage, or are surrounded by high-rise buildings, your device will use GLONASS in conjunction with GPS. This allows your device to be pinpointed by any of the fifty-five satellites around the world, increasing overall accuracy. However, GLONASS is typically only turned on when the GPS signal is poor in order to preserve the device’s battery .
A few apps use GLONASS exclusively for location services. NIKA GLONASS (available for free in the Google Play and iTunes App Store) allows you to track in real-time the location of an Android device. It does require an MTS sim card to work, however.
There is also a feature to make your location public, much like Google Latitude , but that is only available to Russian users.
There are also a number of hardware devices on the market that use GLONASS.
Garmin GLO is a portable GPS and GLONASS receiver which connects to a mobile device over Bluetooth, and provides better accuracy than any integrated receiver. It is available to purchase on Amazon for $99.
Will You Use It?
On its own, GLONASS doesn’t quite match up to GPS. Its satellites are fewer and far between, and aren’t evenly spread throughout the world. GPS is already advancing , and GLONASS seems to forever be playing catch up.
However, you’re not realistically going to use it on its own, but when used in conjunction with GPS, it makes all the difference in the world.
Do any of your devices use GLONASS? Have you ever used it exclusively on its own? I would like to hear your experiences, or just your thoughts on this article.
Image Credits: Glosnass-K Satellite Model 1:1 by Patrick G. via Flickr, Comparison of Satellite Navigation Orbits via Wikimedia, GLONASS or GPS Personal Device via Wikimedia, MOSCOW-June 1: Woman driving training simulator at the international exhibition of navigation equipment and software Navitech on June 1, 2011 in Moscow via Shutterstock