Geofenced Route Data and the Microsoft Band

By Robert Bennett,

The Microsoft Band helps people achieve their wellness goals by tracking their heart rate, steps, calorie burn, and sleep quality. When the band was first released in October 2014, I examined the product literature. The Microsoft Band support page on the Run Tile captured my interest because it refers to hiking: "You can track your running, hiking, even kayaking stats using the Run Tile on your Microsoft Band"1. The same support page displays a Run Tile which includes a route on a map. The map looks great, but its scale is very large. I loaded Microsoft Bing Maps in my browser and zoomed into the location displayed on the Run Tile to see a satellite view of the terrain using a smaller scale. What I found was surprising; the same running route marked on the Run Tile in the support page also exists on Bing Maps, with all its inaccuracies and geofenced data points. I suspect someone at Microsoft forgot to remove the route from Bing Maps.

Microsoft Band - Figure 1

The above satellite image was taken from Microsoft Bing Maps. (I overlaid the orange dotted line and block letters for reference). The faint-grey line in the satellite image (denoted by Microsoft Bing) represents a section of the route denoted in the Microsoft Run Tile copied below. (The Run Tile was copied from the Microsoft Band support page.) Notice the route enters the river at (B). I loaded the image in GIS and measured the length of the route between (A) and (C). I also measured the length of the trail (represented with the orange-dotted line) between (A) and (C). The length of the trail is 0.154 mi and the length of the route is 0.144 mi; the difference is 0.01 mi, or ~53 ft. Most likely, the Run Tile uses accelerometer data to estimate distance; using geofenced GPS geographic data points to calculate distance over time will result in large errors.

With geofencing, a virtual perimeter of a physical location is created; when the perimeter is breached, an action occurs—the geographic position of the device is updated. Geofencing is a concept that some chip makers implement to reduce power consumption and extend battery life. When geofenced geographic data is used to denote a route on a map, the lack of detail and accuracy in the route will become visible as the scale is reduced. What we can see in the satellite images on this page is a run route that is not denoted with multitudinous, highly accurate geographic data points.

The Run Tile illustrated below displays the run route using a large scale, making highly accurate geographic data points less important. In fact, many running, biking and hiking apps will not allow their users to zoom into the route map too far; if they did, the lack of detail and inaccuracies would become visible as you can see in the satellite images on this page.

Calculating accurate metrics and denoting trails on digital maps with a small scale requires multitudinous, highly accurate geographic data points.

For more information, please read: Reliable Trail Data Has Many Uses

Microsoft Band - Figure 2

[ Bing Maps on the left; Run Tile on the right; the two are pasted together. ]

1 Microsoft Band - The Run Tile

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