I notice following cases when I'm missing data in the recording.
Case 1 - when device is busy with route calculation
When device is busy with route calculation I notice that no movement was recorded for some of the points, what was later compensanted with next recording.
You may se many entries with distance 0, and following ones, with distance trying to cover what's missing.
It's a real pity, that when device is calculating the course, it doesn't even update the map view (unless forced with zoom in/out).
The other pity is, that course calculation for ~100km ride takes round 2-5 minutes to calculate, though it was already calculated in Strava, Garmin Connect etc. so it doesn't look like there should be much to calculate. On the other hand, when navigating setting only waitpoint, I get results fairly quickly (like 10 seconds for 10km ride).
Case 2 - rapid speedups when nothing apparent is happening on the device:
You may notice it on points:
2401, 2404, 2409, 2418, 2423, 2427, 2431
On the other hand, there are multiple minutes, when nothing as above can be noticed.
Case 3 - after going through the tunnel, where I lost the gps fix, afterwards, for at least two minutes, no movement was recorded for some of the points, what was later compensanted with next recording.
Notice the points: 15098, 15101, 15107, 15116. GPS fix was restored at 15037
Case 4 - no movement was recorded for some of the points, what was later compensanted with next recording, but no apparent reason:
Notice the points: 1557, 1589.
All data was analyzed in Garmin Basecamp.
I use:
- Garmin HRM2
- Garmin Bike Speed Sensor 2 & Bike Cadence Sensor 2
For speed sensor I use fixed wheel diameter.