Recorded Activity stats page: "area"

Bob_qx 16 days ago

The first info page for a recorded track (activity) shows a total for "Area", a 3D statistic. Why is this present, and what could it possibly mean?

For ex., a recent track has a distance of 0.29 mi, moving avg 1.4 mph, and ascent/descent 56 & 246 ft. All this is accurate.

However, the "Area" of 30,921 sq. ft. cannot pertain to a two-dimensional line. For another track with a length of 2.01 mi the "area" is 71.38 acres (!).

I have asked Garmin Help about this (not recently) but did not receive an answer.

0 twolpert 16 days ago

I rather suspect (but have never investigated) that the unit is creating a closed polygon by connecting the end points of the track. If so, it's pretty meaningless. And I don't even want to think about what it might be doing if the track crosses itself.

You might want to see what it gives you for a closed loop track. That one might be meaningful. For example, you could measure the area of a farm field by walking the perimeter. Not exactly an "outdoor handheld" use case :-D

0 Bob_qx 16 days ago in reply to twolpert

Per your suggestion I just ran a small test track in my driveway, crossing itself at start/end: in this case calculated area seems accurate by observation. Doing that with the usual tracking never occurred to me, especially since there is already a dedicated function called "Area Calculation". I repeated the walk with that function, and it appears that it's the same algorithm, just a different user interface; unfortunately if the attempted polygon is not closed then the same false result is displayed (as with activity tracking). I didn't experiment with figure eights, altitude differences, or other complex topologies :)

That being said, when a track does not close/cross itself, then area should result in Undefined, maybe show "N/A" or blank. So I guess it's a bug that was not deemed important enough to fix.