2019 Jun 7 - The video I analyzed was 2019_05_09_11_32_14_orig.mov, starting at about 21 seconds in. I tracked one of the clouds nearest the drone in the footage as it crossed over tire tracks on the playa. The feature took about four frames to cross over the tracks, which were spaced at about 1.5 m. With a frame rate of 29.97 FPS, four frames corresponds to 0.13 s, so \upsilon = 1.5 m/ 0.13 s \approx 10 m/s.