Speed drops cycling with FusedTrack
I repetitively got speed drops when recording a cycling workout with GPS accurracy set to good (10s with FusedTrack). There seems to be a correlation with the fix itself as the recorded trackpoint is notably off track.
Anyone having the same issue?
@rogge that is entirely possible as the watch is deriving speed from distance travelled due to GPS fixes, and as they are on a 10s fix, if you get a bad fix its entirely possible that your speed may have a massive increase/decrease. Had it before where my walking speed was 25km/hr due to a really bad fix.
What I do is tend to have a variety of fields i.e. have current speed, average speed and lap speed. Makes more sense as you can confirm that you are good on lap base, as well as overall distance traveled so far, and then adjust based on current.
@jamie-bg Thanks a lot for your comments and thougts. I am repetedly cycling in a very flat area and i have regularly these speed drops. Maybe the phenomen has something to do with the area (electromagnetic interference etc.?). I had this also with my former amazfit pace sport watch. This watch showed drops in the measured altitude.
I am still a bit disappointed because in my opinion, the FusedTrack/FusedSpeed etc. algorithm should level these drops out…?
@rogge doubt it would be due to magnetic interference, think the issue is more around fused tracking which takes a fix every 10s, which is fine when you are walking, potentially hiking depending on terrain (not sure how well it works if vertical climb is steep). However if you using a bike, I am not sure it works to well, as you can travel quite a distance in 10s so if you are varying speeds etc, i can see it giving issues.
Try setting it to best (1s) and see how that does.
Also note that what you are seeing isn’t necessarily unusual as GPS while fantastic accuracy is only up to 5m. Watch antenna’s are tiny and often not pointed in ideal directions, and fewer satellite fixes (ability to select and use multiple satellite systems can assist i.e I can use GPS+Gallileo or another system for example) - as coverage depends on hemisphere and region, and terrain features, cloud cover etc can all make that worse.
While your blip (riding through the house) isn’t great is isn’t really that bad either. Your general track is correct, and would focus much more on that rather than precision accuracy which you are unlikely to get without using a device with a much better antenna.