GPS - Why You Experience What You Experience

Engineering
June 8, 2017

You may have noticed that when utilizing Google Maps or any other GPS guidance system on your mobile device that your location is represented by a Circular Dot on a graph. This circular dot has a circular proximity ring which appears to be very small and a specific representation of your latitude and longitude. However, if you zoom in to the smallest point of the dot, you will notice that DOT got pretty big and so is the circle that surrounds it. This is where GPS fluctuations occur. The best mobile guided GPS systems have an error radius of 4.9 meters and 32 feet diameter range (The Facts).

GPS Bubble - Wide.jpg

GPS devices interpret you location based upon the proximity of a geographic radius that surrounds the dot, therefore the device may believe you are anywhere within the proximity of the circle at any given time. Furthermore, not all devices are created equal in regards to software and technical capacity. Therefore it is important to understand that if you are utilizing a GPS transmittable device (your phone) to track your runs, you will face some discrepancy that are predicated upon variables outside of the Metron App.   

This article is predicated upon clarifying the ambiguities that surround GPS running and the fluctuations you may face in data accuracy. No matter what device/system you are utilizing for GPS guidance, you will face some fluctuations in data output/input, this is inevitable.

For example, you go out on a run and maintain a consistent running pace throughout your workout. You may notice that your device notifies you that your speed is faster or slower than what your current pace was even though you did not alter your running pace.

Although these speed fluctuations are not common, they do occur. GPS works by connecting your device to a number of overhead satellites and computes factors such as location and speed by plotting the dots as your device transmits a signal. There are many ways in which companies will use this data to determine your pace and or track your runs.  

For example:

  • Average Pace -  This is derived by your total distance divided by time. Metron utilizes this methodology during our Race Effort Run testing. This is a very simple methodology to implement for shorter runs with no stops, but becomes more complex in nature with longer runs. In addition, when you pause a race effort run the time continues ticking and the gps location will turn off.  This feature will allow you to match your true distance in a race to the actual time that will be logged as opposed to add that additional distance traveled during your rest.
  • Moving Pace -  This is your active distance divided by Time. Metron utilizes this number combined with some other proprietary formulations to compute your pacing during non race effort runs.

In the context of the aforementioned information, it would be advantageous for you to be aware of the structures that can disrupt your signal and cause false data inputs/outputs. It would also be a good practice to keep your device as un obstructed as possible during your runs to give your device the best chance at interacting with the signal overhead.

Avoid These Structures When Running for best Chance of Collecting Accurate Data.

  • Tall Buildings
  • Trees
  • Bridges
  • Tunnels
  • Hills
  • Weather

Metron is working hard to improve our software, as well as to release our very own enabled smart wearable devices for more accurate guidance. The Metron Wearable will allow us to control outside factors such as software & hardware which will be utilized in an effectual manner in comparison to being controlled with a 3rd party smartphone. In addition, we are also working on data discrepancy customer service feature that will allow us to overwrite your data discrepancies however we do not have this feature implemented yet so do you best to avoid the list of structures that interfere with your data.

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