Movie 1: Movie1.avi
High-speed camera footage from experiment 1, with slope angle theta = 16.5°, gate height h_g = 4.8 cm, and flow depth h = 3.5 cm.

Movie 2: Movie2.wmv
An excerpt of the footage in Movie 1, with playback in slow motion.

Movie 3: Movie3.mp4
An illustration of Particle Tracking Velocimetry, using a processed excerpt of the footage from experiment 2, with slope angle theta = 16.5° and flow depth h = 3.6 cm. Particles are tracked, with circles indicating detected particles' centres and lines their tracked historic trajectories. From these trajectories, particle velocities can be extracted, from which both mean and fluctuating velocities may be calculated. The y-axis origin is taken to be at the bottom of the camera's field of view rather than the bottom of the flow.

Movie 4: Movie4.mp4
An illustration of Correlation Image Velocimetry, using an excerpt of high-speed camera footage from experiment 2, with slope angle theta = 16.5° and flow depth h = 3.6 cm. Spatial correlations between subsequent frames are calculated to infer instanteous local mean particle velocities, as represented with red arrows.