River ice and water velocities using the Planet optical cubesat constellation release_rmeno6uaufhlzdfwdsj6bhypli

Abstract

<strong>Abstract.</strong> The PlanetScope constellation consists of ~ 150 optical cubesats that are evenly distributed like strings of pearls in two orbital planes and scan the Earth's land surface once per day with ~ 3 m spatial image resolution. Subsequent cubesats in each of the orbital planes image the Earth surface with a nominal time lapse of ~ 90 s between each other, which produces near-simultaneous pairs of scenes over the across-track overlaps of the cubesat swaths. We exploit this short time lapse between subsequent Planet cubesat images to track river ice floes on Northern rivers as indicators of water surface velocities. The method is demonstrated for a 60 km long reach of the Amur River in Siberia, and a 200 km long reach of the Yukon River, Alaska. The accuracy of the estimated horizontal surface velocities is on the order of ±0.01 m s<sup>−1</sup>. The application of our approach is complicated by cloud cover and low sun angles at high latitudes during the periods where rivers typically carry ice floes, and by the fact that the near-simultaneous swath overlaps by design do not cover the complete Earth surface. Still, the approach enables direct remote sensing of river surface velocities over many cold-region rivers and several times per year – much more frequent and over much larger areas than feasible so far, if at all. We find that freeze-up conditions seem in general to offer ice floes that are more suitable for tracking, and over longer time periods, compared to typical ice break-up conditions. The coverage of river velocities obtained could be particularly useful in combination with satellite measurements of river area, and river surface height and slope.
In application/xml+jats format

Archived Files and Locations