gps-details
Apple Watches
Speed Comparisons
This page looks at a number of wingfoiling and kiteboarding sessions recorded on a selection of Apple Watches.
It focuses on the difference between software-calculated speeds (simply using latitudes and longitudes), versus speeds calculated by the GNSS chipsets (almost certainly using the Doppler observables).
Notes:
- The charts are very basic in nature (e.g. simple legends and lack of axis labels), saving time during production.
- The units for speed are m/s, but you can double the values to approximate the speed in knots.
- The data was recorded without any filters applied, thus showing the true nature of the raw GNSS data.
- Whilst standard speed sailing filters can remove some spikes in the software-calculated speeds, they are not 100% effective.
- Doppler-derived speeds are far more robust than software-calculated speeds that rely on longitudes and latitudes.
Apple Watch Ultra
Apple Watch Ultra #1 - Wingfoiling
Large spikes are clearly evident in speeds calculated from latitude and longitude, especially after a crash / fall.
Apple Watch Ultra #2 - Wingfoiling
A large spike is clearly evident in speeds calculated from latitude and longitude, likely due to a crash / fall.
Apple Watch Ultra #3 - Kitesurfing
Large spikes are clearly evident in speeds calculated from latitude and longitude, especially after a crash / fall.
Apple Watch Ultra #4 - Wingfoiling
Large spikes are clearly evident in speeds calculated from latitude and longitude, especially after a crash / fall.
Apple Watch SE 40 mm Cellular
Apple Watch SE 40 mm Cellular #1 - Kiteboarding (or maybe Wingfoiling)
Large spikes are clearly evident in speeds calculated from latitude and longitude, especially after a crash / fall.
Apple Watch SE 44 mm
Apple Watch SE 44 mm #1 - Kiteboarding
A large spike is clearly evident in speeds calculated from latitude and longitude, likely due to a crash / fall.
Apple Series 8 45 mm Cellular
A further investigation might wish to look into whether the cellular models of Apple Watches suffer from RF interference?
Apple Series 8 45 mm Cellular #1 - Kiteboarding
Large spikes are clearly evident in speeds calculated from latitude and longitude, especially after a crash / fall.
Apple Series 8 45 mm Cellular #2 - Kiteboarding
Large spikes are clearly evident in speeds calculated from latitude and longitude, especially after a crash / fall.
Apple Watches Series 5
Apple Watches Series 5 #1 - Wingfoiling
Significant spikes are clearly evident in speeds calculated from latitude and longitude, especially after a crash / fall.
Apple Watches Series 5 #2 - Wingfoiling
Significant spikes are clearly evident in speeds calculated from latitude and longitude, especially after a crash / fall.
Summary
- Speeds calculated in software from longitude and latitude can be extremely unreliable.
- Speeds calculated by the devices (almost certainly using the Doppler observables) are far more robust.