Abstract: The changes in coastline form and location have a profound impact on marine ecology,resource development and coastal economy.Taking the Illinois Beach park beach in the United States as the research object,its on-board point cloud data from 2018 to 2024 is processed to optimize data quality in the paper.In response to the sparse problem of ocean point clouds,Poisson reconstruction method is used to supplement it to improve the integrity and accuracy of DEM.Combined with the DEM contour thick extraction and supervision classification methods,the coastline is initially fitted,and the on-board image is accurately adjusted to ensure that the coastline data is accurate and reliable.The precisely extracted information such as the length and torsion rate of the coastline is compared and analyzed.The study find that the length and torsional rate of the coastline in this area were basically stable and showed a slight upward trend,indicating that there was seawater erosion; but the artificial intervention project launched in spring 2023 effectively slowed down coastal erosion and enhanced the stability of the coastal zone.

Key words: airborne LiDAR point clouds, cloth simulation filtering, coastline extraction, coastline analysis