Stuff and things I have found that is useful

OK, some posts I have seen are along the lines of "My Garmin says I did 5.1km yet my running buddy's FitBit says 5.2km" Both are probably within the design limits but here is a way to compare the two on the same map. All sites that take the data should allow you to download it in GPX format - this is more or less a requirement under data laws around the world - certainly in the EU & UK the GDPR made this so. Get the GPX files of each run. You will need a Google account - everyone with an Android phone will have one - this will give yuo the ability to create your own maps - go to  https://www.google.com/maps/d/u/0/  .  PRess Create a new map And then Import Layer Select the first GPX file, then rename it so you know which/whose run it was Repeat for your buddy's or the other day's trace you want to compare Change the style of the second and subsequent lines   You can then see where each route has any GPS oddities in it and se...

So, I got myself a Garmin Forerunner 3 - a basic running watch from Garmin, good enough for what I need I also spent a bit of time re-plotting the route using the high accuracy OS Mastermap.  MasterMap in my neck of the woods is captured at 1:2,500 - which means it is 99% confident to be within 2.4 meters of the real world - see https://www.ordnancesurvey.co.uk/business-government/tools-support/mastermap-topography-support - without going out with survey gear and stuff, it is as good as you can get in most of the UK.  (Larger urban areas are captured at 1:1,250 but those be big scary places, like Exmouth) Using the new route I re-analysed the Gear Fit data and 4 runs with the Garmin, and here are the results - you can sort by the various measures (getting this working on Blogger took WAY longer than it should have) device error area samples device distance (Dd) OS distance (OSd) ...

Further Analysis with Gear Fit 2 OK, so one one wasn't really representative, so I did two more, here's the results Run 1 - Sample points 457, error area 56576 Run 2 - Sample points 447, error area 30765 Run 3 - Sample points 474, error area 28162 So three very different results. Next steps....welll I've gone and bought a Garmin so I guess the next steps will be to do this exercise again with that. Part 5

Enter FME FME is a massively powerful GIS data manipulation tool.  For professional use it isn't cheap, but those very nice people at Safe Software (who make FME) allow free Home use - if you ask them nicely and say what you plan to do with it.   I have a little experience with FME from work, and work with someone with a shed load more (many thanks Matt) so with my ideas and his pointers as to what tools to use, I have made this first attempt at quantifying accuracy. Let's look at a recent run The yellow line is a best fit line using open source mapping and google aerial images. The red is what my Gear Fit tracked. Now, my working theory is that by making polygons between these two (the grey areas) I should get a measure of how good the tracker was.  The smaller the overall area, the better the track was on that day The results for this first test are below - The overall Error Area (as i am calling it) is 56576.6 m2 - a lot of tha...

Theories and first attempt at quantifying In Part 1 I went over the background of this, the question is what is best to use for tracking runs (or any other activity) - phones, running watches or general fitness trackers. I concluded that as the chipsets all promised similar accuracies,  then other factors may play a part. My thinking is that there are a few things that could help or hinder Physical size of device - the bigger the device, the bigger the aerial The targeted design - Running Watches will, I hope, be designed to get the best signal, so may have bigger/better aerials than phones The location/orientation - if you have your phone upright in a back pocket the aerials may well be orientated in the worse way for signal reception - a wrist watch should be better Age of the device - runners who say "phones are rubbish" may have last tried using old phones, as lots of us have old phones to take out running rather than their newest ones.  Who wants to s...

Part 1 - Why? OK, on various posts on the Lonely Goat Facebook Running Club group people have talked about accuracy of their devices they use to track runs. Frequently I have seen comments like "You should get a running watch" or "You're using a phone, phones are not good at tracking" Now, I can't let that go.  Over the last 15 years, part of my day job has been to provide support and advice on GIS . Part of this has involved setting up "in field" data capture using various GPS tech. My immediate predecessor where I worked had spent a large sum of money on massive GPS units.  These were never used as the were powered by heavy lead/acid batteries and were worn like a backpack. Since then ,every so often I've delved into the world of GPS an looked at the accuracy. Phones and wearables, as far as I know all have similar accuracy and depend on a few factors. The number of satellites it can see The availability of A-GPS ...