The Garmin GLO is a small GPS/GLONASS receiver that sends 10 position fixes per second to an external device such as a tablet, laptop or smartphone using wireless Bluetooth® technology.
Garmin has primarily targeted the GLO to users of tablets (such as the wifi iPad) that don’t have internal GPS chips and smartphones with internal chips that aren’t especially accurate. But it may be used with laptop computers or any other device capable of receiving position data via Bluetooth®. My own use of the GLO has been with navigation software running on an HP Slate 500 Windows 7 tablet computer.
The basic GLO package includes the device itself, a rechargeable battery, USB charging cable and a 12 volt automotive charger. Garmin also offers a GLO aviation bundle that adds a friction mat and a trial version of Garmin Pilot™
The friction mat is an attractive and functional accessory that keeps the GLO from sliding around in a moving vehicle. It works well on the dashboard but I’m using it on the center console as the weather gets warmer. The GLO itself has rubber feet in each corner and sat comfortably in the recessed tray on my dashboard without the mat as well.
The GLO is one of those devices that is mostly sold at the full MSRP of $99, however I was able to find a vendor (MacMall) offering it for $90 after a bit of digging. Curiously, no vendors could match Garmin’s own $15 price for the mat. A belt clip is also available for about $5.
Bluetooth® GPS receivers were once popular items, but today there are very few choices available. The GLO is similar in appearance to Garmin’s discontinued GPS10x Bluetooth® device.
The Dual Electronics XGPS150A is arguably the main competition for the GLO, but it lacks GLONASS capability and provides positions updates at a slower rate. Personally, I prefer the black, professional look of the GLO to the bright red “sporty” looking XGPS105A. This is completely a matter of personal style of course.
The Qstarz GPSXT10hz was the only other currently shipping device I could find. It also offers position updates 10 times per second (10hz) like the GLO, but does not have GLONASS.
The GLO is simplicity itself; a little black box with a power button, two LED’s and a mini USB port. The USB port is used only for powering the device and charging the battery, it cannot communicate with an external device over USB. The LED on the power button indicates whether the unit has a GPS fix and whether the battery is charging. This is one of the few things I dislike about the GLO, you must decode what different patterns and colors of the flashing LED’s are trying to tell you. The chart included in the manual is rather confusing. A separate blue LED indicates whether the GLO has established a Bluetooth® connection.
After inserting the battery (with some difficulty – see below) I powered up the GLO and connected it to a wall charger. Within a matter of seconds it acquired a satellite fix sitting on my desk inside; I was impressed. I have never seen it take more than a few seconds to obtain a fix since then.
The simplicity of the GLO hardware might be viewed as either a blessing or a curse depending on your point of view. On the plus side, you don’t need to learn how to use any controls or software. Just turn it on and pair it using the Bluetooth® menu on your tablet or phone. Garmin does not provide any special drivers or software for the GLO. I did not experience any problems with my Windows 7 tablet and although I didn’t have any software to test it, my MacBook Air computer and iPhone 4 also had no problem pairing with the GLO.
When I went to Garmin’s site to register the GLO, I was initially confused. Garmin’s registration procedure asks you to connect your GPS via USB and use the Communicator plug-in to detect it. But, of course, the GLO has no USB interface and is not recognized by Communicator. After some trial and error, I found that you could just “lie” and tell Garmin that you have a marine device. With this option, you get a screen on which you can enter the GLO serial number. This was correctly recognized and my GLO was registered. Tip: after registering your GLO you will get a 10% discount code for accessories. This might be handy if you want to purchase the mat, belt clip, etc.
One small nitpick: I found the battery compartment latch rather un-intuitive and had a hard time opening the door to insert the battery. Maybe it was just me? I finally tried prying it open with a pen-knife, and actually popped the latch and retaining spring out of their track. Happily, no damage was done. The proper technique is to simply slide the latch away from the door, which will release it.
Garmin’s spec calls for 12-hour battery life, and my own tests tend to confirm this. In one test, I left the GLO running continuously for about 13 hours until the LED indicated low battery. During almost 12 of those hours, the GLO was paired with my Windows tablet and providing position data to a running program. In a second test, the GLO ran for over 14 hours until the low battery light came on, however this time it was not constantly connected to a running program.
I used the Garmin USB wall charger that came with my Montana 600 to charge the GLO without problems. Garmin also includes a cable that can charge the GLO through any USB port. The GLO is fully functional while charging, so the included 12 volt car charger should easily get you through a long day even if the battery runs down.
An FAQ at Garmin support says that the GLO must actually be powered on in order to charge the battery. This was surprising; I can’t think of any other device that behaves like this.
Additional Garmin GLO FAQ’s are found here.
My Windows 7 tablet had no trouble finding and pairing with the GLO (although it identified it as a “headset”), and created a virtual COM port which legacy applications can use to communicate as though it were a serial GPS device. Throughout almost two weeks of usage, there was only one incident where the computer could not connect to the GLO. Power cycling the GLO quickly corrected that. As a new user of Bluetooth® GPS receivers, I was pleasantly surprised at how trouble-free the GLO was. It quickly reconnects to the computer following sleep and was free from the many glitches I have experienced with my hard-wired USB GPS receiver (a Microsoft/Navigation device that originally came with Streets and Trips).
The GLO provides position updates 10 times each second (10hz) as opposed to Garmin’s handheld units which only update once per second (1hz). The main application for this higher data rate would be aviation use where higher speeds require a faster device. Older software will likely not take advantage of the higher update rate, but it generally was not a problem for me. Even Garmin’s ancient nRoute software worked properly when used in conjunction with GPSGate.
My only issue was Microsoft Streets and Trips 2009, which connected to the GLO without problem but quickly crashed. Another Windows user reports that his newer version of Streets and Trips did not crash when using the GLO, but it placed a large load on the system and the position of his vehicle on the screen lagged behind the actual location when driving.
My main use for the GLO has been Mobile PC, a Windows program which Garmin discontinued almost two years ago. Basically, it turns your computer into a large Nuvi with some advanced features. It was able to correctly track my position and “felt” more responsive than my older GPS, so I think it’s actually using the higher data rate of the GLO. However, when recording a track it did not show any more points than the older GPS.
OziExplorer was my only Windows software that was able to record a track with the full 10hz data stream from the GLO. And there were some small gaps, presumably from where the software wasn’t able to “keep up” with the GLO. See the test results below for more on this.
There is no way to configure the GLO to provide a slower update rate. It is completely up to the application programs you use. This is my other (minor) complaint about the GLO. It would be nice if Garmin provided some software to control the GLO and provide status information. For example, there’s no way to know the status of the battery charge aside from the flashing LED when connected to the charger. And older software doesn’t quite “understand” the larger number of satellites that are available with GLONASS.
The 10z update rate may not necessarily be a good thing, depending on your use. It can place a higher load on your device’s CPU if it has to re-draw the screen more frequently. This might also cause faster battery drain on a mobile device. But I did a test on my Windows tablet while running Mobile PC. I was pleasantly surprised to find that the tablet ran 15% longer when connected to the GLO over Bluetooth® compared to a hardwired USB GPS. So the energy needed for the wireless connection and higher update rate was still less than what was needed to power an external USB device.
Since I don’t have an iPad or Android tablet, I’m not able to offer any insights as to how the GLO will perform with them. However, GPSCity has some helpful videos, Q&A’s and customer reviews on their site.
I performed a variety of tests using my Windows tablet and the results were somewhat mixed. None of my older Windows software was capable of showing the full number of satellites the GLO was receiving nor could it display an “accuracy” (EPE) reading – presumably due to the newer GLONASS technology. However the software did report the GLO receiving signals from between 13 to 18 satellites – very impressive.
In the first test, I placed my Garmin GPSMap 60csx, Montana 600 and GLO on a table at a known location with a good view of the sky. I left all three devices sit for about 20 minutes to “settle in” and then recorded a track for 30 minutes at one point per second. The two handhelds were using WAAS. This resulted in approximately 1800 points being recorded by each device (30 minutes x 60 points). Afterwards, I took this data, converted the tracks to individual points and added range rings spaced at 2 meter intervals using Globalmapper, a powerful GIS software package.
The results (shown above) were quite interesting. The 60csx and Montana show quite a large scatter of points, however if you were to average them they would come quite close to the center of the target. This was not at all surprising, based on my experience with these devices.
But the GLO displayed an extremely tight pattern of points, all of which were within 4 meters of “ground zero”. Looking at the chart, it’s hard to believe there are really 1800 points, but there are. Many of them are right on top of each other. Statistically, 100% of the GLO points were accurate within 4 meters and 75% were within 3 meters. Garmin’s spec for the GLO calls for 3 meter accuracy. By comparison, 94% of the 60csx points were within 10 meters and 87% of the Montana points were within 10 meters.
This leads me to conclude that the GLO’s greatest strength might be obtaining static position readings – such as the location of a survey stake on your property.
On the trail (see images above), the results were much less impressive. It showed an error of as much as 10 meters during the beginning of the test with the 60csx and Montana (which had good WAAS locks) performing much better. To be fair, I also did some other tracking tests where the GLO performed better, but they were not as carefully controlled as the comparison shown here. I would characterize its track recording performance while hiking as “average”.
I also did some testing in the car (see images above) driving at a speed of around 15-20 mph on a sand road in the state forest. These tracks looked very good, even better than the Montana. In these tests, the Montana was not using WAAS, which might have been a factor in its performance.
In all of the tests above, the GLO was providing position data directly to GlobalMapper which was running on my Windows tablet and recording one point per second. I did another test using OziExplorer, just to see what a log would look like with 10 points per second. The GLO performed very well in this test, accurately recording a “loop” that I walked at the intersection of two sand roads in the New Jersey Pine Barrens. Note how closely these points are spaced!
Technical note: the NJGIN 2007 orthoimagery shown in the examples above has a resolution of 1 foot (~31cm) per pixel and is accurate within +/- 4 feet (~1.25 meters). This sort of error in georeferencing might skew your interpretation of the tracks, so I suggest that you mostly consider the variation in tracks between the different devices and not the absolute position of the road when viewed at such an extreme zoom level.
Conclusion and recommendation
All in all, I am completely pleased with the GLO. It makes a perfect companion to my Windows tablet computer in the car – my primary use. Static position accuracy is impressive, and I will probably use it to confirm previous position readings I’ve taken of my property corners with a 60csx and Oregon 400t. Track recording at driving speeds is equal to what I’ve seen on any of my various devices.
Performance at walking speed was less impressive, but not beyond the range of expectations for a consumer device. Further testing is needed before drawing any firm conclusions. However, I will say that the GLO is not going to replace my Montana for use on the trail.
If you are using an application on a smartphone, the GLO is likely to be a significant upgrade from the internal GPS chip. And if you use a tablet computer without an internal GPS, the GLO should be a nice accessory. Since I did not test the GLO in this role however, I’d encourage you to do a little further research regarding compatibility and performance with your platform (iOS or Android) and your chosen app(s).
Garmin GLO pros
- Excellent accuracy in static tests
- Very fast satellite acquisition
- GLONASS compatible
- 10 hz position update rate
- Good compatibility with Windows 7 OS and software
- Good battery life
- Attractive styling
Garmin GLO cons
- Lackluster track results at walking speed
- Confusing battery cover latch
- Bright LED’s distracting if placed on dashboard for night driving
- Confusing status indications from multi-colored flashing LED’s
- No Garmin software to provide device status and configuration
- Unit starts immediately when power button is pushed, subjecting it to accidental activation while stored in a pack
More Garmin GLO reviews
- Consumer-authored Garmin GLO reviews have been posted at Amazon
- Piaw’s Blog has also posted a Garmin GLO review
- A Garmin GLO + iPhone review
- A brief GLO review from It’s Not About the Numbers
- Another brief review from Mac Life
I’ll be posting more hands on GPS reviews as they appear, but in the meantime, here are some…
Other Garmin GLO resources
- The official Garmin GLO web page
Compare prices on the Garmin GLO at these merchants:
- Check the current Garmin Portable Bluetooth GPS and GLONASS Receiver price at Amazon
- Get the Garmin GLO at GPS City
- Check out the deal on the Garmin GLO at MacMall
- Buy the Garmin GLO direct from Garmin