23 Sep 2025

Wave Kinematics-Based Bathymetry Estimates from Satellite Optical Video

Abstract: Here, cBathyShortDwell, a version of the spectral depth inversion algorithm cBathy adapted for shorter record lengths, was applied to four 29.9-60s satellite-based optical videos and the resulting bathymetry estimates were compared to surveys collected within 13 days of each satellite collect. The Planet SkySat videos were collected at the ERDC Field Research Facility between April and September 2023. The videos were collected at 30Hz with a ground sampling pixel resolution of 0.75-1 m and an image size of approximately 2.5km x 1km. RMSEs from post-processed cBathyShortDwell depth estimates over the 800 m x 1100 m analysis domain using the entire video duration at a 5 Hz frame rate ranged from 0.50 to 0.59 m with biases ranging from -0.19 to 0.16 m. Although some differences were seen in the RMSEs as a function of frame rate, larger differences were observed due to video length, wave visibility in the imagery, and incident wave conditions. The highest RMSEs were observed in short video lengths or low wave visibility. These results are comparable to published RMSE values from established versions of the algorithm and demonstrate the ability of cBathyShortDwell to provide good depth estimates from satellite videos in a range of environmental conditions.