How to get better GPS-Tracking Accuracy in Workout Apps – Guide

The runner has discovered that the official race distances are determined by a bicycle-mounted tachometer (cyclometer) rather than GPS, which often overestimates the distance.

We care a lot about accuracy when it comes to MapMyRun. We spend a lot of time talking to people about the app, and one of the most common questions we get is about accuracy. We are continually looking for ways to improve it, given its importance. To improve MapMyRun’s accuracy, we’ve made several adjustments to the way we filter GPS data. This was no small undertaking. Thousands of races were analyzed, routes were measured by hand in several cities and hundreds of tests were carried out. ..

How to get better gps tracking accuracy in workout apps

Developing a new GPS filter

  • We tested the new GPS filtering technology with a variety of methods, including measured courses, race tracks and results from other products.
  • We found that the improved filtering offers a high level of accuracy when compared to measured courses, race tracks and results from other products.
  • Overall, we believe that this new GPS filtering technology is an important addition to MapMyRun and will help athletes avoid large GPS errors and overestimations when tracking workouts.

The first step was to test the existing GPS filtering system to see if there were any improvements that could be made. We analyzed the data collected in a highly controlled environment, measuring routes with a cyclometer to see if there was any discrepancy between GPS-based distance and cyclometer-determined distance. We found that the existing GPS filtering system overestimated the distance by 4-6%. ..

We tested the existing GPS filtering system in a semi-controlled environment. Using technology that identifies races tracked by MapMyRun (as described in US Patent number 10331707B2), we identified over 500 races sanctioned by US Athletics (i.e., race courses were measured with a cyclometer). Comparing MapMyRun’s GPS-based distance, we found that the existing GPS filtering system overestimated the distance by the same 4-6% that we saw in our own controlled tests. The similar results in overestimation error with the controlled and semi-controlled tests gave us confidence in our baseline and gave us a significant target for improvement.

We took a close look at our GPS filters and identified several fixes that could improve accuracy, using this 4-6% overestimation as our baseline. We took advantage of numerical simulations to optimize our changes to the GPS filters, which reduced the occurrence of individual errors by 50%. This error reduction was mainly achieved by reducing the overestimation tendencies of the original GPS filters. Overestimation is caused by including incorrect GPS points in a tracked workout. Errors in these points cause the total distance to be longer than the actual training distance. Therefore, when the new GPS filters are applied and fewer errors become part of a workout, the speed and distance of the workout will be less than it would be with the old GPS filters or without any filters.

We validated the new GPS filters by re-running all the tests above with the new filters. We found that the new GPS filters significantly outperformed the original filters. The new GPS filters have reduced the overestimation to 2–3%, down from 4–6% with the original filters. We also compared the results of the same tests with the results obtained by Garmin™ wrist-based GPS running trackers and found that the new GPS filters produced distances of 1% for wrist-based running trackers, compared to 3-5% for the wrist-based running trackers.

Final note

If you’re looking to get better GPS tracking accuracy when working out with an app, this guide is for you. We’ll outline the best practices for setting up your device and app, and explain how to tweak settings to get the most accurate tracking. If you have any questions or concerns, feel free to reach out to us. And finally, share this guide with your friends so they can get the most out of their workouts too! ..