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GLONASS, Galileo, BeiDou and QZSS | What it is and when to use it

What they bring above the GPS


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Until not many years ago, GPS watches were so called because they simply allowed to receive data from GPS satellites. We continue to call them GPS or GPS watches, but the truth is that it is a wrong name from the moment when the watches already allow receiving signal from GLONASS, Galileo, BeiDou and QZSS satellites.

We have remained with the designation GPS, which is the acronym for Global Positioning System, to name any device that allows to triangulate a position from satellite data, but GPS is only one of the satellite constellations available. What would be the correct term? GNSS, Global Navigation Satellite System, which would encompass all satellite positioning systems.

Currently GNSS chipsets already have been supporting GLONASS and Galileo satellites for quite some time, and more recently BeiDou and QZSS have also been added. These chipsets are those that subsequently equip the different devices whether they be watches, mobile phones, fridges or any other electronic device that has a global positioning system. Yeah, any day your fridge will have GPS.

When we see the product specification datasheet, compatibility with GLONASS, Galileo or other systems always appears prominently. When there are no more important developments to mention, referring to small changes is always a good point to hold on to.

But, is it so important that your new watch has Glonass/Galileo/Beidou/QZSS compatibility? Is your current bike computer, which only receives GPS signal, outdated? And, therefore, will it stop working because it has no compatibility with other types of satellites? Or will you have a much more accurate track? Well, all these questions are what I will try to answer in this post.

What is GPS

It is the original positioning system, which is why we know it as "...".GPS"in a familiar way to any device capable of displaying our location.

It uses a total of 32 satellites (started with 24) that orbit about 20.200km from earth. They have been distributed so that there are always at least 4 satellites visible from anywhere on the planet. Therefore, no matter where you are, you will always be able to triangulate your position with greater or lesser accuracy (the greater number of satellites visible, the more accurate triangulation).


It is owned by the United States Space Force, which is also responsible for its maintenance. It was developed by the army in the 1960s for military purposes only, to be used as a navigation system by the Navy. And so it was until, in 1983, President Ronald Reagan opened its use to the general public.

Originally they had no intention of opening public use, however the decision was made following a Soviet SU-15 identification error when it shot down a Korean commercial aircraft. But the public version would have its accuracy altered to an approximate radius of 100m in order to maintain an advantage for military use, thus ensuring more accurate data.


This also changed later (in 2000, during President Bill Clinton's term), so the accuracy is now determined by the device used and its specs, without any induced error.


The positioning system GLONASS is a direct legacy of the Cold War. Its name comes from the acronym "ГЛЛОбальная НАвигационнная Спутниковая Система" which, after having a few glasses of Vodka, podranslate as "Global'naya Navigatsionnaya Sputnikovaya Sistema". In short, it is Russia's answer to the GPS satellite system deployed by the United States.

Suunto 9 GLONASS

It consists of 31 satellites orbiting 19,100 km from earth. Not all of them are operational. There are three groups of 8 satellites orbiting at different points on the planet (providing global service), remaining for backup and different tests.

As with GPS, at first there was also an induced error (about 30 meters), removing such restrictions in 2007 to allow unlimited commercial use.

Both GPS and GLONASS have a military start that has finally been given civilian use by all the inhabitants of the planet. Currently they are the most used, but they are not the only ones. BeiDou has already started working, as has QZSS.

What is Galileo

For its part, the European Union (together with the European Space Agency) has launched the Galileo programme, which is for civilian use from the outset and promises a level of accuracy never before seen. The main difference Galileo will have is that, being for civilian use, its accuracy will depend on your wallet. Paying a fee will get you better performance, although there are still a few years to find out how this subscription model will work.

Garmin FR945 Galileo

🔥 🤑 Los mejores precios todos los días

Unlike GPS and GLONASS, the Galileo system is still being deployed and, although it began at the end of 2016, it is estimated that its implementation will not be complete until 2020, although everything seems to indicate that the deadline will not be met.

There are currently a total of 26 satellites deployed. 22 are in usable condition, 2 are not available for use and 2 are in testing. The goal is to complete the constellation with up to 30 satellites.

Galileo satellites

But as indicated above there are (or will be) several modes of use. What matters to us in our type of use is the open service, with an accuracy of up to 1 meter. But for that you will need a GPS receiver (misnamed, because I as I said that GPS is the American system) that supports the use of dual band, something we haven't seen in watches or bike computers yet.

It is certainly the next step in GPS watch location capability, but no positioning chips are yet commercially available for use in wearables.

Then there will be other kind of payment services with more location accuracy (up to 1cm of error!), but believe me when I tell you that it is not something you should consider because it would be killing flies with guns.

What is BeiDou

BeiDou (Great Bear in Chinese) is the satellite system of the People's Republic of China. It was initially launched only for China with a limited number of satellites. We are currently in the third generation, which already offers global coverage.


BeiDou completed its constellation of 35 satellites with the launch of its last satellite into orbit a month ago, thus being the system that offers a larger constellation and, according to the Chinese National Space Agency, is able to offer an accuracy of up to 10cm.

What is QZSS

QZSS, which comes from Quasi-Zenith Satellite System, is somewhat different from the previous ones. It is a development of Japan, but its goal is not to provide a global constellation as is the case with GPS, GLONASS and BeiDou; it is a correction system for the GPS system in Asia and Oceania, with special focus on Japan.

Polar QZSS

Currently only 4 satellites are available, with the intention of reaching up to 7 by 2023. But unless you are in that indicated area their use does not represent any improvement because there is no visibility to these satellites from other parts of the planet.

Why so many constellations?

After the review done to all existing satellite systems, I'm sure you ask yourself that question. Why are there so many satellite systems, instead of all collaborating on one of them? It is because of the military origin of the first systems, and because it is something unique to those countries.

At any time GPS, or GLONASS, could be disabled or degraded use, leaving not only millions of users without possibility of using it but also (and more importantly) blocking the navigation of ships, planes and all types of vehicles.

However, having so many different constellations is positive for users from the moment that we can use more than one system simultaneously, thus increasing the total number of satellites with which we can triangulate our position.

Benefits of using GLONASS/Galileo/BeiDou

The use of GLONASS, Galileo or BeiDou confuses many users. Many people think that using this option will directly increase localization accuracy. Or even the other way around. In fact I have come to read in more than one forum that it is better not to activate the use of GLONASS satellites because, far from improving the location, it makes it worse.

The reality is that the improvement of location is not direct, but rather indirect by increasing the number of satellites on which the device can rely to fix a position. Therefore it always depends on the situation you are in.

The benefit lies in the increased number of satellites from which to obtain positioning information, but it has a cost: increased battery consumption.

Should you use Glonass/Galileo/Beidou whenever possible?

With the advancement of technology, the answer to this question has changed. Some years ago the impact on the watches battery life was greater, because the consumption of watches was higher. The recommendation had always been to use only the GPS system to save battery, except if we were in difficult reception locations where it might be interesting to activate the use of other systems.

With current watches, battery life has grown exponentially. Especially in the newer models that equip the Sony GNSS chipset with very low battery consumption. So that reduction in battery life is no longer such a determining factor, and you can use more systems more carefree.

But you must understand that using more than one constellation will not cause your accuracy to improve noticeably. For you to understand better, I'll give you an example with fabricated data.

Imagine that you are running in the countryside on a treeless plain, therefore with a full view of the sky. That is to say, an ideal situation. At that moment your device may be picking up signals from 8-10 satellites of the GPS system, so the location will be quite precise. If you had the option of using GLONASS or Galileo active you could pick up, in addition to the previous 8-10 satellites, another 8-10 satellites of the Russian or European system. But the precision is not going to double, because in the first case it was already very good and you are not going to notice any difference.

Now you change training places. You get into a forest in a very mountainous area. You're running along a steep mountain surrounded by lush trees. That means there's hardly any visibility of the sky.

Your device, which used to pick up signals from 8-10 satellites, now cannot get them from more than 2 or 3, so the accuracy will be quite low or even impossible to triangulate (a minimum of three satellites is required).

At this moment you also activate GLONASS and you get signal from 2 or 3 other Russian satellites. You go from having data from 2 or 3 satellites with very bad results to 4-6. The results will still not be very accurate, but at least there will be location.

So everything depends on the training areas you use. If these are complicated locations, it is advisable to enable the use of GLONASS, Galileo or QZSS satellites, despite the reduction of battery life (around 15%). But if you usually run in open spaces without trees, mountains or buildings, you can leave the option off with total peace of mind, as you will hardly see any difference in performance.

What is clear is that by no means the use of GLONASS/Galileo/QZSS will reduce accuracy in location, all you are doing is increasing the number of satellites available for triangulation.

And remember that location accuracy does not depend exclusively on the chipset used by the watch or device, or whether it supports GLONASS/Galileo/BeiDou or not. More important is the design of the antenna and the management done by its firmware.

There are many examples of watches with GLONASS support that do not behave as well as others that do not have it, but have a better placed antenna (for example, Ambit3 watches that have a non-integrated antenna).

What is the best combination of satellites you should use

Well, I'm sorry to tell you there's no common answer I can give you. The best advice I can offer you is to try, because it all depends on where you are located. Below I will give you some indications of what has worked best for me right now, but it's not an absolute value because manufacturers continue to work on firmware improvements and will also depend on other variables.


With Garmin we have the option to use only GPS, or combine it with GLONASS or Galileo. In both cases it does so to support the GPS signal. That is, you can use GPS + GLONASS or GPS + Galileo; but not GLONASS + Galileo. The use of GPS is non-negotiable, at least for the moment. Nor will it allow us to opt for GLONASS + Galileo. At the moment they do not offer support for BeiDou.

I configure Garmin devices with GPS+GLONASS, it is the option that gives me the best results with the new Sony chipsets.


Polar does not contemplate the exclusive use of GPS, it must always be in combination with other services: GPS + GLONASS, GPS + Galileo or GPS + QZSS.

Dismissing the third option (which as I indicated above would only be valid if we are in Oceania), I have unquestionably obtained the best performance with GPS + Galileo. The GPS+GLONASS combination has always led me to location errors that are not punctual, but persist for a few minutes, as you can see in the analysis of the Polar Grit X.


Suunto has recently been working on satellite reception, adding different possibilities. At all times they combine the use of GPS + QZSS, no matter where we are. It also offers us the joint use of this system with any of the other constellations.

  • GPS + QZSS + Galileo
  • GPS + QZSS + BeiDou

And which one do I keep? I think the third option is the one that offers slightly higher performance, although it is not an abysmal difference from the other two options. As I said, the best thing you can do is try out the different options and see what convinces you most.


COROS currently does not use Galileo and only allows you to combine GPS + GLONASS or GPS + BeiDou. There is a third option that is to use GPS exclusively.

In the tests I have done I have not noticed great differences with regard to the use of GLONASS or BeiDou, obtaining very similar results in all cases.

But I repeat, the most important thing to keep in mind is that these are the results I have obtained in my particular use and in the area I am. It can be similar to yours or totally different.

At least now that you have a more basic knowledge of what everything is and what it is for, it will allow you to make a more accurate choice.

And with that... thanks for reading!

Eduardo Mateos

I've been surrounded by electronic devices of all kinds for more than 25 years. Using them, testing them, taking them apart and dissecting them. Long distance triathlete: I swim, run and cycle for a long time. Maybe too much.

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  1. Good article! The truth is that I always carry it off because I prefer that extra battery to the supposedly greater precision that I have noticed in tests I have done so far.

    1. I usually turn it off because for better or worse I almost always run parallel to the sea. No trees, buildings, mountains, etc. That is, perfect coverage, so adding some more satellites is not going to change my experience much.

      It's like I'm a billionaire and I'm playing the lottery...

  2. Excellent article, the truth is that you have cleared up some doubts I had about the Glonass and if it really brings always better positioning, but almost better to have an extra battery available, except for the problem cases that you say it can be good to activate it.

  3. A great article, I didn't know what the glonass was or what it was for, so I left it off... After reading the article I prefer the extra battery. Thanks, a greeting.

  4. Thank you for the article, although it contains some important errors:

    It should be noted that, although Galileo is not fully deployed, it is in an initial service phase, with 22 operational satellites, which are provided completely free of charge. For the street user, this makes practically no difference to the benefits he will obtain with Full Operational Capability. In short, Galileo can already be used perfectly in conjunction with GPS, Glonass and Beidou, freely and globally. And no, the greater precision that the system will provide with its high-precision service will not cost either.
    The battery usage depends on the number of channels in the receiver. If there are only a few (as is usually the case), it does not matter if one or several systems are activated: these channels will be 'filled' with the first satellites you catch.

    To find out if your device is equipped with Galileo, visit http://www.usegalileo.euAnd for any questions about the programme, the Galileo Service Centre in Madrid ( is at your disposal.

    1. Thank you, Emilio, for your first-hand information.

      In the case of Garmin, which are the ones that do allow you to play with the configuration of which satellites to search for, you can check the difference in autonomy of that 15% when only GPS is activated or if GLONASS or Galileo is added. As for the paid service, I was referring to the one specified on the web as "Commercial Service (CS)" which, I understand, will have a cost, right? (

    2. For those of us who have an already powerful gps watch (in my case a fenix 3), I don't plan to change it until sports gps watches are "gps dual band" and the Galileo system is fully deployed (by next year). This will be a real breakthrough in terms of positional accuracy and therefore a much more realistic calculation of distances and live running paces in a sports gps watch, until then (I estimate that at best there will be models of this in 2021 almost certainly) there won't be a real qualitative leap in these wonderful little gadgets. When they incorporate this, it will be time to retire my fenix 3.

    3. How can you tell if a device is equipped with a dual band chip like the Xiaomi Mi8, many times the manufacturers don't indicate it. For example the new Samsung S10 comes with a galileo compatible gps chip, but is it gps dual band? Definitely, there is a list of galileo compatible devices but I don't see a list of galileo dual band compatible devices.

      P.S.: is there a date (even if it is the month) for the launch of the 4 satellites that are missing to complete the constellation?

  5. I don't think the information you're providing is correct.
    If you have 2 GPS satellites and 3 glonasses in sight, you don't have 5 satellites, since the positioning systems don't share information between them. So it's not worth it, what the device does is to choose from the available systems the most favorable one and not the sum of all of them.

    And the watches already incorporated glonass from the vertical 3 scope .

    1. If you have 2 GPS satellites and 3 GLONASS satellites you have 5 points with which the watch can triangulate, regardless of who is giving the information.

      The Suunto Spartan came on the market without GLONASS support, was added later.

    1. Thank you, I have already updated it to include the details of the Suunto 2.8.24 update.

  6. Good afternoon for suunto 9 baro that you suggest gps , gps glonaas or galileo, I usually run by madrid river there are buildings and some trees, but the buildings are separated, in my case, a greeting.

    1. In Madrid Rio you have a very wide area where you shouldn't have signal problems. With GPS you should only have good reception at all times, however GPS+GLONASS won't hurt either if you don't need the range (something Suunto 9 has plenty of).

  7. Good afternoon, Eduardo,
    In my case, I live in Asturias and at the moment, just like your land, I start my journey to the seashore. At least during the week for my training. However, on each of my outings I set my watch to go out from a height of about 30m when it should really be close to 0.
    Perhaps it is a question of adjustment rather than the use of GPS GLONNES or GALILEO.
    Could you help me?
    Thank you in advance

    1. It's simply because of what I explain in the article about altitude and air pressure. The pressure is variable, so from one day to the next it's normal that it doesn't always mark the same even if you made a calibration 3 hours ago.

  8. Too bad, I know it wasn't the same as buying the Suunto9 BAR, but I didn't think I'd find these differences in an open space like the one I'm in, but rather in altitude, like peaks for example.
    Even my garmin Forerunner 225 gave me more accurate values.
    Thank you for everything.

    1. Las diferencias de presión son habituales, si un día está soleado puede que estés a una altura de 0 metros pero el aparato te dé una altura de -20 metros y si el día está nublado puede que la altura te la marque bien o te dé más de la real. Eso me suele ocurrir a mí con mi Igpsport que utilizo en la bici. Pero si descargas los datos en Strava, esta página tiene una opción para corregir estos errores autamaticamente, ya que ahí si toma los datos reales del mapa. Un saludo y espero haberte ayudado.

  9. Great article!
    How about the running miles accuracy? That's what I basically use a Garmin for, my first one is the 401. extremely accurate on the miles I was running, mountain or flat area. I compared them to the runners that were using suntus and high priced Garmin watch pieces. they were off almost 2 miles. Yep, the foretex 401, as big as it is and not sexy and doesn't make my ass look big seems to be the most reliable. your thoughts, please.

    1. They are different animals...

      The 401 is not a watch, but a navigation handheld unit. Therefore is way bigger, so the GPS antenna is also much bigger.

      Also, it works with AAA batteries, so it doesn't have to put up with power saving.

      Those are the main reasons why, despite it's age, it works equally or better than today's watches.

  10. to see if you can enlighten me podeis. I have for months suunto 9 without baro. It is up to date and in good condition. I go running and no matter if it is cloudy, sunny, mountain or asphalt day, it always makes me most of the track on the outer edge of the routes invading ditches and hills. It is rare the section that coincides with the roads or tracks. What is the curious thing is that the distance is the same as if I do the route in google earth?

  11. Hi! loved the article, congratulations!

    I would like to point out that these satellites, as far as I know, do not follow geostationary orbits (at the equator and with the same angular velocity as the earth, i.e. 24 hours/turn). Therefore, they do not occupy fixed locations in the sky and, for that reason, they occupy spaces far from the mean earth orbit (MEO), to gain angle, so that each satellite reaches the maximum surface at each instant, and the system needs fewer satellites.

    I point this out because it is forcibly wrong to say that Japanese satellites are not visible from other points on the planet. They are all over the planet. Yes, it is likely that the system is focused so that there is always one or more satellites over Japan, and that the system is not effective, therefore, in any other place. And nothing, that is the nuance, hehe.

    Nothing else, best regards!

    1. The case of QZSS is different. Of the 4 satellites they have in operation, one of them is geostationary. The other three are in a "quasi-zenith orbit", and draw an 8-shaped orbit between Japan and Oceania, with special emphasis on Japan.

      This zenithal characteristic gives them an advantage, and that is that when the satellite orbit is over Japan, it is at a high altitude and almost on the vertical of the cities, thus avoiding the bounce effect that can exist with the buildings when the satellite signal comes with inclination.

      You can take a look at the explanation on the official website, here:

  12. So, in Spain, what would you recommend? In general it would be better not to go with the Chinese I understand?

    1. It depends on each watch. At the end of the article you have a list of recommendations, anyway it is best that you go testing in your particular case, as there is no "absolute value".

  13. Hi! I love the blog and the website in general, I get very important information and it helps me to improve my workouts.

    I wanted to ask you something that I don't know if it makes much sense, but I need it to decide on a quality GPS watch. I train mostly on asphalt, around the city of Valencia. I only train in the mountains two days a month, although it is true that I would like to do it more, but right now because of my situation I can not. Maybe in asphalt I train a 85% and a 15% in the mountains and/or on the beach (sand).

    For me, distance accuracy is very important, that is, that it has a good GPS without major faults. That would allow me to know the more or less real distance and therefore the race pace, and everything becomes more reliable. What watch or watches would you recommend that you have seen that have a good GPS accuracy?

    Another question, in relation to what you wrote in the blog today: if you reset the watch, do you lose all your training data?

    Thank you for all the work you do.
    Greetings from Valencia,

    1. Thank you, Javier.

      Fortunately, the GPS reception of any of them is really good. Except for specific cases there are no major differences from one model to another and we have several possibilities to improve the record. If you do not run in areas of complicated coverage you will not have problems with the measurement, and if it is a complicated area it will be for any GPS watch.

      Training data is not lost when the watch is restarted as long as it is already synchronized in its corresponding platform.

      1. Thank you very much Eduardo for your response.

        One question, apart from Glonass, Galileo, GPS, etc... do you know what possibilities there are to improve the registry? I might go for the Garmin 245 or the Polar Grit X. You haven't noticed much difference between their GPS, have you? Thanks for the help, it is very helpful for me to choose the watch.

        A hug.

        1. For what it's worth. I'm with suunto 9, plain and simple. I am reasonably happy. Very easy to use and no gadgets that often go unused. The Gps performance is good, the updates left it fine with the measurements of strava or trainingpeaks and the battery gives you 10-15 days. Yes, the mobile notifications greatly lower the performance and does not go beyond a week at most. Garmin for me has a lot of extra that I will not use and polar is a step below, in my opinion.

  14. Hi, thanks for the blog. I left a comment but I think it failed to post.

    I was wondering if you could recommend me a good GPS watch that is quite accurate measuring the distance and that has almost no errors in the tracks. I'm thinking of buying a mid-high range watch, and I train mostly on asphalt and on the beach, although two or three times a month I go to the mountains to train, although it will be the 10% of my training.

    Thank you for everything,

  15. Hello
    I have the garmin fenix 6x and recently I was in the Pyrenees doing a route. I was very surprised that having activated the gps+ galileo gave me such a big error in a particular area. The area I'm talking about is Gavarnie. It is an area that has a lot of mountain with a lot of slope.
    Do you know if there is a website, where you can choose the best option, depending on your location? Gps+Glonas or Gps+galileo
    The truth is that with the money that many of the Gps are worth today, I think that they themselves would have to adapt to the best option and thus surely also improve battery life.

  16. Hello,
    I'm an open water swimmer and with my Suunto Spartan Sport Wrist Hr I'm not able to get it to map out a route for me that doesn't look like I'm swimming drunk... (zig zags, switchbacks... etc.) and if there's one thing I have going for me it's that I swim straight as a sail.
    I have tried setting the GPS to maximum, do you think activating Glonass would help me to plot a more accurate route?

    Thank you and good article

    1. It won't solve much because the difficulty lies in how the measurement is done (every time you put your hand in the water the watch loses GPS signal, it only recovers it in the short space that is outside). It's true that the Spartan Sport never stood out for its open water swimming algorithm...

  17. Good afternoon eduardo, first of all congratulate you for your work, I have a suunto 9 baro, which I used with beidou, after a few weeks it gives me more meters than the fenix 6x and the polar grit x, what would you advise me to use the gps glonass or galileo to try, as I told you before I run by madrid rio, you answered me that in that area with gps I should not have problems and to use the glonass, the truth that I did not use it much because the other mode of gps was working. So you continue to advise me to use glonass or galileo.

  18. What gives more constellations is greater coverage, so that in dense wooded areas, near tall buildings for shielding, etc ... to poder achieve observe more satellites, it will give us the position that otherwise might not give us.
    And it also improves the position reception response time when starting the instrument, precisely for the same reason.

    P.S: I am a surveyor.

  19. I would like to point out that Coros now has implemented all 5 systems to be used. Galileo was recently rolled out to all the watches (or soon to be all) and QZSS has been available now for a while. Also, on their most recent newest watch, Vertix 2, Coros has enabled dual frequency and ALL systems on GNSS features.

  20. Excellent article. Especially the results with different brands of watches or devices. Thank you very much for your contribution and clarification in such a changing and sometimes confusing world.

  21. Me ha parecido un excelente artículo. Entré en la página simplemente porque encontré un dispositivo compatible con el sistema Qzss y no tenía ni idea de donde era y ahora me ha quedado muy claro, al igual que alguna que otra duda sobre los aparatos compatibles gnss. Un saludo y gracias por el artículo.

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