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A GPS For a Class Project

Hello everyone,

I am in a college computation course need a project for the end of the semester. My plan is to use various interpolation methods to play "connect-the-dots" and map a mountain biking trail.

To do this I need a GPS capable of outputting recorded position and altitude to a spreadsheet so that I can actually use the data in Matlab. My experience with GP systems is limited to navigating with my IPhone, so I really don't know where to begin looking. Here are the features I need:

-Spreadsheet Output (I need the raw data)
-Reasonable Accuracy (It doesn't have to be an pinpoint map)
-Durability (It will be jostled around on a mountain bike)
-Small Form Factor (I'd rather not lug a 7 pound brick up a mountain)
-Automatic Recording (I don't want to stop every few meters to press a button)
-Mounting Method (I could throw it in a backpack but mounting it on the bike would be easier)

The university has offered to buy such a device for me so price is not a huge problem. Again, my experience with these devices is basically nonexistent so I don't know how common these features are.

Thanks for the help! I'm excited for this project!

Comments

  • privet01 145 Points
    edited February 28
    What do you call raw data? The unprocessed satellite signals? you won't get that with a comsumer gps. If you are talking position coordinates, then just about any are at least the ones I'm familiar will create a file, typically a .gpx, .tcx or other file that is simply a text file in a markup language similar to HTML that you can easily pull out the data to put in a spreadsheet if you need it that way.

    Reasonable accuracy, all consumer GPS's are pretty much accurate to roughly 30 feet when conditions are bad to about 4 feet when conditions are excellent.

    Durability.... Garmin makes GPS specifically for bicycling. Any of them are rugged enough for mountain biking. They market them under their "fitness device" category. They also make GPS's that you can wear on your wrist. They market some in their "on the trail" others in the "fitness device" category. Pay attention to how you get the track information from the device. Most of the bicycle gps's use a usb cable to PC. Many of the wristworn devices use a proprietary wireless that requires a dongle.

    Small form factor....... in the categories I mentioned above, they are small and light. Ounces, not pounds.

    Automatic recording. You just need to push start for the "fitness devices" the on the trail might record anytime they are on by default, but I've not used the wrist worn on the trail so I'm not certain.

    Mounting method..... Wrist worn... well there you go. The bicycle gps's come with a 1/4 turn mount that easily mounts to your bike stem or handlebars. I've not had any trouble with it on bumpy rides.

    For Garmin you are probably in the 250 to 400 dollar range. There is a very good bike computer made by Lezyne that is about 150 dollars.
  • Boyd 1786 Points
    edited February 28
    I would have a look at the Garmin GLO. It's a very small bluetooth GPS receiver with good accuracy, price is around $100. Now it doesn't have any display, memory or user interface - it just sends position data over bluetooth to another device such as a phone, tablet or laptop computer. So you will be dependent on the device and the app that you choose. But there are many, many apps on iOS and Android to choose from.

    I reviewed the GLO back in 2013: http://gpstracklog.com/2013/04/garmin-glo-review.html

    More recently, I did some further testing and was impressed with the accuracy: http://forums.gpsreview.net/discussion/30108/what-is-gps-accuracy-testing-the-garmin-glo-in-the-forest

    You would have to look at different apps on the platform of your choice to see what capabilities they have. Almost any app is capable of saving gps data in the form of a .gpx file. One nice thing about the GLO is the quantity of data that it outputs - 10 position updates per second. Phones and handheld GPS devices only output one position per second.
  • privet01 145 Points
    Boyd said:

    One nice thing about the GLO is the quantity of data that it outputs - 10 position updates per second. Phones and handheld GPS devices only output one position per second.

    That's a good point. Though many of the devices that I described do log down to one position per second, there are some that won't log that often. Even within the same Garmin line such as Edge, Forerunner, etc, there some oddball models that have significant differences in specs, operation and behavior.

  • privet01 145 Points
    Oh... a point we didn't touch on is altitude/elevation. GPS signals are not as accurate in the vertical dimension. I personally can't think of any current consumer device still in production that acutally uses GPS elevation. A barometric sensor is included in many consumer GPS's to provide this information. The science and engineering behind it is much more accurate, but there are gotcha's. One being the static air pressure reference and the other being that methods to reference the current sensed pressure to what the actual pressure relative to sea level are crude if enabled at all.
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