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Garmin GLO Bluetooth GLONASS receiver
Boyd
I bought Streets and Trips 2009 a number of years ago and hated it. Tried it again briefly when I first got the Slate and it worked, but seemed almost useless on the touchscreen so I uninstalled it.

But - for the good of the cause - I dug out the DVD, copied to a flash drive and re-installed on the Slate. I let it scan automatically and it detected the GLO on COM6. When I enabled it from the GPS task pane, it correctly showed my position (still inside my house) and said it had a signal from 12 satellites.

A few seconds afterwards, the program crashed. Tried again and the results were about the same, it worked briefly then crashed. So I tried GPSGate next, then let S&T re-scan. This time it found the virtual GPS on COM9 (did not recognize any of the other GPSGate virtual ports).

But the results were pretty much the same. It locked in to my position and ran briefly, then crashed. On one of the crashes, the dialog box and said it might be due to a lack of memory or resources. But I suspect S&T just can't handle the 10hz refresh.

So, score one for Microsoft. Garmin's ancient nRoute works with the GLO but not S&T 2009. I'll leave it installed briefly in case anyone has questions or suggestions, but it doesn't look like it will work. And even if it did, I just don't think it's usable on a tablet and I can think of better things to fill up the Slate's 64GB SSD.
Marvin Hlavac
Quote:
I don't know if GPSGate was adjusting the refresh rate or if nRoute is able to deal with that itself.
I think you would only be able to determine that while driving. Once I tried Microsoft Streets & Trips, which only can handle 1Hz, feeding it with 5Hz. It worked on the parking lot, but as I started to drive it was not able to keep up with my speed, the location icon on the map was moving slower than the speed of my vehicle, and my position on the map started to lag. When I then stopped my vehicle, the vehicle on the map kept on moving till it finally reached my actual location. That software in such configuration would be useless for real-time navigation, but it was fun testing it.

Mine was only a brief test. It is possible if I drove more than a minute the software would have crashed.
Boyd
Did a quick test while out running errands. nRoute tracks just fine using the GPSGate translated data from the GLO. My topo map is very complex, and nRoute never could scroll it smoothly. But the performance seems exactly the same as it did with the USB GPS.

OziExplorer also worked fine and I used the direct connection to the GLO through COM6 at 115k that I'd configured earlier. Again, performance has never been very impressive here because it's raster imagery on a netbook class processor.

Neither of these programs are at all friendy on a touchscreen, and I don't really plan much use for them in the future. Mobile PC is far more responsive, and also the only software I have that works well on a touchscreen.

Later today I'll try to get out and record a tracklog with both Ozi and nRoute, just for fun. I am curious to see how often they can record trackpoints and how they compare to my Montana 1hz log.
Ken in Regina
Hi Boyd,

Just a reminder to treat Mobile PC like a device. That is, it is trivial to transfer tracks from Mobile PC into Mapsource if you just remember to use the Transfer From Device function in Mapsource. Select Mobile PC in the device list and the tracks will transfer straight into Mapsource.


Same deal for loading maps into Mobile PC. If the maps are in Mapsource, use the same method as loading maps from Mapsource into your Nuvi or Montana.

...ken...
Boyd
Yes Ken, I am constantly updating my own maps and sending them from Mapsource to MobilePC after each revision. I do this on my desktop system running the software in a 1024x600 window in demo mode (no GPS or City Navigator, only my own map). You have to click through a few warnings but then it all works. When I have done my debugging on the desktop machine, I just copy the gmapsupp.img file to the MobilePC directory on the Slate.

I posted earlier that I didn't have any luck reading my MobilePC tracks in Mapsource. Mapsource recognizes Mobile PC and tries to open, then puts up an alert that it cannot open Current.gpx because it isn't a proper .gpx file (or something like that).

I copied the Current.gpx file to my desktop machine and Mapsource couldn't open it there either. Was fed up enough with Garmin's software at that point so I didn't try Basecamp. But GlobalMapper opened it right up and it contained my current track, saved tracks, waypoints and routes - just like I would have expected.
Ken in Regina
That's interesting. And surprising. I never had any trouble with transferring stuff both ways between Mapsource 6.16.3 (the last version made) and Mobile PC. At least you found a way to get the stuff out of it without losing it.

...ken...
Boyd
Here are some more track comparisons. I used GlobalMapper again and overlaid the tracks on the NJ 2007 Orthoimagery. The Montana 600 was set to record 1 point per second, as before. The GLO was connected to OziExplorer via COM6 at 115k baud. Both devices were sitting right next to each other on the dashboard. I couldn't find an option to record tracks by time interval in Ozi, only by distance. So I chose a distance of 10 feet. Obviously the software didn't comply as these points are much farther apart than 10 feet.




And here's a closer look.

Boyd
Next I used GLO with nRoute via GPSgate at the maximum setting, which is also 1 point per second, like the Montana.




Here's a closeup.




This is hardly enough data to be a scientific experiment, but I would say that the GLO is recording more accurate tracks than the Montana (which I believe uses the ST Cartesio chipset).

Unfortunately, none of my software can capture anywhere near the full 10 points per second that the GLO is capable of. But at least nRoute can do 1 point per second. Maybe I'll take a closer look at Globalmapper. It can receive data from a GPS and may have more advanced track recording capabilities.
Boyd
FWIW, I was surprised by how small the GLO was when it arrived. The product photos don't give a very good sense of scale, so I took this picture to provide a frame of reference to anyone else who may not be familiar with the GLO.

Boyd
Did some tests today with surprising results. I recorded a track for about 30 minutes using the GLO, the Montana 600 and the GPSMap 60csx. This created about 1800 data points for each device (1 per second). I then used double-precision (survey grade) coordinates in GlobalMapper to convert the tracklogs to points and add range rings.

The Montana and 60csx looked about like what I expected - the 60csx still holds its own, creating a pretty tight pattern. However the Montana had a bigger spread but more points close to ground zero. Nevertheless, if you averaged the data it looks like each device was within about 5 meters - maybe better - of ground zero (which is what their specs call for).

Now at first glance, the GLO looks very disappointing, with points wandering way off to the Southeast.




But when I looked more closely I found a different story. Notice how the GLO didn't really seem to record 1800 points. In fact, they're all there but many of them are on top of each other. And the points outside the 10m circle are mostly just single ones. Out of a total of 1862 points, only 41 were off by more than 10 meters. 98% of the GLO's points were within 10 meters and 87% where withing 3 meters.

I didn't analyze the data from the other devices, but you can see the Montana and 60csx were within 10 meters almost all the time. However, neither of them had anywhere near 87% of their points fall within 3 meters - that is a really tight pattern from the GLO. So I'm impressed




Note: when looking at the images above, you have to realize we're zoomed WAY in. To put this in context, the screenshot below shows the Montana trackpoints at the maximum zoom in Mapsource (80 ft) vs GlobalMapper at 1:200.

Boyd
After making the tests above I realized that WAAS was not active on the Montana and 60csx. I also feared that I might have messed up the track log for the GLO. I recorded it in Globalmapper and the user interface is awkward - especially on a tablet in the bright sun. Furthermore, that "wandering" part of the track looked suspiciosly like a trail from my house to the test point.

So here are the results of my new test. I'm certain that I recorded all these tracks correctly, and WAAS was enabled on the Montana and 60csx. I guess the GPS constellation wasn't as good this morning?

But - wow - that GLO track just blows me away. The bottom image is at the scale of 1:40. the others are 1:200. Obviously a lot of the GLO track points are right on top of each other.













Marvin Hlavac
That's impressive. Thanks for taking the time to do the tests and for posting them here. It seems that indeed using both, GPS and GLONASS, results in better accuracy than using GPS alone.
Boyd
Glad that you're finding them interesting. The GLO is certainly a completely different animal from the SiRF based 60csx and STM based Montana. I still wonder whether the update rate is a factor somehow. For example, when GlobalMapper recorded one point per second, was that point actually the average of 10 samples from the GLO?

I'm glad I decided to get the GLO instead of the other devices. I'm a believer now... I don't think I would buy another device without GLONASS.
Boyd
Just made a minor discovery. Looks like OziExplorer can actually record the full 10hz data stream. There was a menu choice I wasn't correctly grasping: File > Configuration > Moving Map > Store Track Point Interval.

I tried a value of 1 foot here before, but 0 is also a valid choice. This allows data to be recorded even if you have not moved from the previous position. Will have to try this out with a longer log. But I just did a quick test where I counted to 10 and the track file had over 100 entries.
Marvin Hlavac
If there was a way to use GLO with the hardware version of Garmin Mobile PC, I'd seriously consider buying it. I wonder if Garmin would be willing to "de-activate" my 10x GPS which came with GMPC, and instead enable a GLO to work with my GMPC (including my Lifetime map subscription). What is the chance of that I wonder.
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