[Closed] GPS Data

Pretty much any GPS watch will do that. Garmin watches will store the data in a FIT file so you'd need to convert that to XML but there are plenty of utilities available to do that.

Apart from the technical challenge of doing it yourself (nothing wrong with that BTW) you are reinventing the wheel somewhat.

Pretty sure any GPS device will do that. You can use your phone or something like a Garmin watch. Probably cheaper than any of the bike devices. Or pick up an old handheld Garmin

Phone + free Strava account will do this.
Set your runs/rides to private, and don't friend anyone if you want the data to be yours alone.

that was my starting point but was put off by the cost of Strava premium but interesting to hear that I. Ah still be able to get the raw data to the free account. Do you use it? Will it give me accurate data do you think when used with an ios

Would a dedicated gps device be more accurate than a smartphone do you think?

A decent dedicated device should be more accurate yes. How accurate do you need though. For cars phones are way to slow to be accurate but for bikes they should be enough. Recording in woods isn't the best environment for accuracy anyway

Are you just wanting to record your runs or do you have a small project in mind manipulating the data?

The GPS in phones is accurate (in terms of consumer devices), it's usually the battery life that's the issue.

Sounds like you are overthinking this. Just logging a run/ride and having it uploaded/displayed on a site like Strava is what these devices do. I've a Strava free account and there's several thousand runs and rides on there. I've got programs/sites like veloviewer and intervals.icu linked up to it so that when I upload an activity it's automatically sent to them so I can plot it on a map alongside all my other activities or analyse HR and power data.

@nixie cheers for that, I'm going to try the Garmin 130 Edge as it's reasonbly cheap and I'll see what comes out of it

@whitestone I'm coming at this from a few angles, I do need a small data project to work on in my personal time so to know I can export the data is just what I needed to know for now thanks as it gives me something to work with for that.

I'm slowly getting back into biking after a while out and having never used a GPS I'd love to see what data these devices can offer but it has to be something that doesnt get in the way of the ride. I can't stand seeing people on trails all staring into these devices. I want to hit start put it in the pocket and forget about it and then review the data post ride. The only data I would be intesrted in to begin with is distance, time and elevation.

I'm not completly sure what I'll do with the data yet until I know a bit more about what I can extract, or more importantly how accurate it is. Ideally I just want to have a start and end time between two points. It will really come down to how fine the cordinates can be plotted. I will however definatly be giving Strava a go first though as it does seem to do what I want I agree with you there

OK.

The bike oriented Garmin units export their data as a FIT file. This is a proprietary Garmin binary data file format but the spec is available so it's not too hard to parse and get the data out of it. Done this way as it's compact. General use units (the Etrex series, Oregon, Dakota and the like) export their data as GPX files which is just XML plain text.

Here's a line from a GPX file I recorded - "trkpt" is short for "track point", i.e. location:
<trkpt lat="53.9849573001" lon="-2.1052987967"><ele>122.11</ele><time>2020-01-05T10:09:35Z</time></trkpt>
There can be several thousand of those for a typical file!

What gets recorded does depend on what sensors you have, HR, power, temperature, etc.

Accuracy depends on a lot of things but unless the Americans have turned on Selective Availability (i.e. scrambling) as they are about to attack someone then in open terrain and with a reasonable spread of satellites in the sky you'd be looking at about 4 metres resolution (this from the US government), so you'd be able to tell the difference between one side of the road and the other. The satellites are in low earth orbit so constantly move, sometimes all you'll have for a few minutes are either "bunched up" in the sky or very close to the horizon. In these situations the accuracy will be lower. Also the more satellites your receiver can see the better accuracy you'll have, you need a minimum of three for lat/long and four for lat, long and elevation.

General use units have a screen that shows the position in the sky of the visible satellites.

You don't have to upload the data at all to review/analyse it. Just transfer it to your computer (I presume they still do USB cables for Garmins). Download GoldenCheetah and import the activity into that. Basically GoldenCheetah has all the data analysis features that Strava Premimum offers, including the creation of segments, but none of the social aspect so no comparison with your friends or strangers and of course no sharing of your data with big corporate data. GoldenCheetah is really more setup for serious road cyclists, but it has lots of options so can be tweaked to show whatever information you want. Bit of a learning curve though to get it there. You can also setup keywords, etc, and then make sure you tag your activities with them so once you've got a few hundred activities filtering them become really useful, say for digging out an old route, and the data analysis can also be applied to the filtered activities, ie disregard runs or social rides or commutes etc. Without HR & power data it's less useful, but you've still got distance, speed, ascent/descent, time-moving, min/max/avg etc so still numbers to crunch.

unless the Americans have turned on Selective Availability

turned off permanently nearly 20yrs ago...

Isn't this what the lap/auto lap function on most Garmins is for?

Gpsbabel is good for extracting/converting all the different brands gps formats, and various manipulations I think. Been a while since Ive used it.
I thought gps didn't give elevation well. The garmin I have has an altimeter of some kind in for that. Or you can get elevation from some map data of the location.

Or you can get elevation from some map data of the location.

@uniqueusername great idea, this is what I'll hopefully end up doing myself at some stage in the future

@cookeaa was the first thing that jumped out at me when I switched the device on having ust picked up the Garmin Edge 130 Plus, not sure yet exactly how it works but I assume I can set a start and end point

@whitestone

“trkpt” is short for “track point”

is exactly what I needed to hear thanks

as for the accuarcy I think I'll just have to see how I get on, I know when I last went riding in the peak district my friend had a gps unit and I calculated the distance and elevation manaully and our numbers compared reasonably well but on a smaller scale I am not quite so sure. so long as I can comare a like for liek to begin with I should be good.

I"m not sure I fully understand the sensors requirement, the device wants me to connect something else to it?

Sensors are optional they're for heart rate, power, cadence, and lights (is rear light brightens as you decelerate quickly).

Does sound a but like you're reinventing the wheel.

Are you writing code to do this? There are a few open source libraries around that will be helpful, depending on language used.

@sirromj thanks I'll skip sensors for now and yeah totally reinventing the wheel, I've logged in to Garmin Connect and Strava and they both have what I want plus loads more than what I need, it's quite hard to see the reason why I should but that might not stop me having a go and see what comes out if it, just need to work out how to parse the fit file format before I can do anything by the sounds of it

@whitstone using the FIT SDK I've converted a FIT file to .csv successfully, not sure how I can do the same for .gpx though, how do you obtain your .gpx files?

Nothing wrong with reinventing the wheel. Just because someone else has done something is no reason not to have a go yourself. The end result may be a slightly crappier version of what is available, but some times the journey is the fun, and maybe along the way you learn something that you get to put to use in something else more novel in the future.

I've a Garmin Oregon, GPX is its file format. In the starting block of the file is a link to the schema file which is basically the rules that the file must follow in laying out the data. An XML parser will look at that schema or schemas and then know how to interpret the file.

This is what that looks like:
<gpx xmlns="http://www.topografix.com/GPX/1/1" xmlns:gpxx="http://www.garmin.com/xmlschemas/GpxExtensions/v3" xmlns:gpxtrkx="http://www.garmin.com/xmlschemas/TrackStatsExtension/v1" xmlns:wptx1="http://www.garmin.com/xmlschemas/WaypointExtension/v1" xmlns:gpxtpx="http://www.garmin.com/xmlschemas/TrackPointExtension/v1" creator="Oregon 600" version="1.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd http://www.garmin.com/xmlschemas/GpxExtensions/v3 http://www8.garmin.com/xmlschemas/GpxExtensionsv3.xsd http://www.garmin.com/xmlschemas/TrackStatsExtension/v1 http://www8.garmin.com/xmlschemas/TrackStatsExtension.xsd http://www.garmin.com/xmlschemas/WaypointExtension/v1 http://www8.garmin.com/xmlschemas/WaypointExtensionv1.xsd http://www.garmin.com/xmlschemas/TrackPointExtension/v1 http://www.garmin.com/xmlschemas/TrackPointExtensionv1.xs d">

You can start to see why using an existing utility or library makes sense.

@whitestone I’ll see if my device exports directly to .gpx too that would be much easier. I’m using the Garmin 130 Plus

All you need is a free app called GPSLogger on an Android phone. It records a GPX file which you can then upload to Dropbox or various other services to get it onto a PC. It's generally accurate enough although you occasionally get some outlier observations which can be corrected using the Ordnance Survey route planner.