This study evaluates an emerging capability to monitor high spatial (pixel size = 3.7 m) and temporal (daily to sub-daily imagery) resolution coastal change using PlanetScope cubesats. A new toolkit (CoastSat.PlanetScope) is presented that enables users to map shorelines from PlanetScope imagery, using a workflow of image co-registration, segmentation, thresholding, shoreline detection and elevation correction. The toolkit is subsequently tested at Narrabeen-Collaroy Beach (SE Australia), evaluating combinations of shoreline detection indices, thresholding approaches and elevation correction. An optimal shoreline accuracy of 3.5 m (RMSE) is found for this coastline using the difference between the near-infrared and blue bands and a weighted peaks thresholding approach. A generic elevation correction model that considers tidal variability and wave setup at the shoreline is then proposed. With a growing archive of high-resolution imagery, PlanetScope presents enormous potential for enhanced coastline mapping of the coast and complements existing approaches using Landsat/Sentinel-2 imagery.

本研究评估了使用 PlanetScope 立方体卫星监测高空间（像素大小 = 3.7 m）和时间（每日到次每日图像）分辨率海岸变化的新兴能力。一个新的工具包（CoastSat.PlanetScope) 呈现，使用户能够使用图像配准、分割、阈值、海岸线检测和高程校正的工作流程，从 PlanetScope 图像绘制海岸线。该工具包随后在 Narrabeen-Collaroy 海滩（澳大利亚东南部）进行了测试，评估了海岸线检测指数、阈值方法和海拔校正的组合。使用近红外和蓝色波段之间的差异以及加权峰值阈值方法，为该海岸线找到了 3.5 m (RMSE) 的最佳海岸线精度。然后提出了一个考虑潮汐变化和海岸线波浪设置的通用高程校正模型。随着高分辨率图像档案的不断增加，