gps-details

COROS Activity Testing

Author: Michael George

Created: 9 July 2024

Overview

This page documents activity testing that was performed on 2024-06-30, whilst walking in an open-sky environment.

It compares speedsurfing against windsurfing, and also looks at two custom activities.

• COROS APEX 2 Pro - Firmware V3.0408.0
  • Windsurfing
  • Speedsurfing
  • Custom Activity (Sailing)
  • Custom Activity (Driving)

1 Hz and 5 Hz data was also collected using Motion Minis.

The devices were carried as shown in this photograph, including a Garmin Forerunner 255 on the right:

Data

All of the FIT data is available for download in ZIP format:

• 2024-06-30-walking-apex-2-pro.zip - APEX 2 Pro

The OAO data from the Motions is available for download in ZIP format:

• 2024-06-30-walking-motion.zip - Motions @ 1 Hz and 5 Hz

Observations

Windsurfing

The image below shows how position-derived speed and Doppler-derived speed are very similar. There are some fluctuations, but speed and position are clearly smoothed. Intriguing that the smoothing of speed and position produces similar results.

Speedsurfing

The image below shows how the speedsurfing activity looks quite different to the windsurfing activity. This is due to a bug in the firmware V3.0408.0 (released in May 2024) which adversely affected the speed data.

Custom Activity (Sailing)

The position-derived speeds (green) are reminiscent of the data from run / hike / walk activities in the previous test. The speed data looks a little different though and the is not exhibiting the same type of filtering / smoothing.

Custom Activity (Driving)

The position-derived speeds (green) are reminiscent of the data from run / hike / walk activities in the previous test. The speed data looks a little different though and the is not exhibiting the same type of filtering / smoothing.

Comparison

Comparison of the speeds for Windsurfing (red), Speedsurfing (green), Custom - Sailing (magenta), Custom - Driving (yellow) vs 5 Hz Motion (blue):

Notes:

• The filtering / smoothing of speed data for speedsurfing (green) is clearly different to the windsurfing activity.
  • This is due to a bug in the firmware V3.0408.0 (released in May 2024) which adversely affected the speed data.
• It is interesting to contrast this data with that of the Garmin Forerunner 255, since it uses the same Airoha AG3335M chipset.
  • The Garmin Forerunner 255 results for this test session can be found on a separate page.

Summary

Windsurfing

• Position-derived speed and Doppler-derived speed are very similar.
• Some fluctuations, but both are clearly smoothed.
• Intriguing that the smoothing of speed and position produces similar results.

Speedsurfing

• Position-derived speed and Doppler-derived speed are clearly different.
• Doppler-derived speed is heavily filtered.

Custom Activities

• Speed is heavily filtered / smoothed, but not quite so much as running / hiking / walking.
• Position is potentially filtered but more choppy than bike / flatwater / windsurfing / GPS cardio.