What cameras and sensors measure

Video shows movement in the frame

A recording lets you examine arm and torso position, the approach and the exit. Neighbouring frames help identify the beginning and end of a jump phase.

Camera angle matters: an angle in an image is not necessarily the angle between body segments in space. A hidden skate means the camera cannot observe its ice contact. A model-reconstructed point remains an estimate, not a direct measurement.

Sensors record acceleration and rotation

An inertial sensor usually includes an accelerometer and a gyroscope. The accelerometer measures specific force; the gyroscope measures the device’s angular velocity. Readings depend on orientation and mounting.

These signals do not directly provide skating speed or jump quality. Calculations require calibration, gravity compensation and a validated method. Errors can accumulate over time.

Align the recordings in time

To compare a frame with a sensor reading, establish that they represent the same moment. The camera and sensor may start recording at different times, and their clocks can drift.

A similar-looking chart peak alone does not establish alignment. Check timestamps and the synchronisation method before connecting a signal to takeoff or landing.

When the sources disagree

Check the angle, skate visibility, sensor mounting, calibration and timeline. A difference between sources does not always mean a change in technique.

SkateLab sensor support is in development. See Camera and sensors for more, or use the recording guide to prepare video footage.