Mapping Coral Reef Complexes using Airborne LiDAR Bathymetry Technology

Underwater mapping based on a green laser LiDAR bathymetry system from the air has been a proven productive technique since the early 1990's. The airborne LiDAR bathymetry (ALB) technology has been applied to the global range of marine and coastal environments and from the Arctic to the Tropics. In many settings, it offers the only practical and safe means to obtain comprehensive maps of complex or extensive shallow (drying features to depth limit of safe navigation) coastal and offshore features. Since ALB is most productive in clearer waters, it has been shown to be especially effective for mapping of coral reef areas (Australia, Red Sea, Caribbean Basin, Florida, Indian Ocean, etc.). These can be very complex extents of shoals, drying reefs, and wide zones of waters too shallow for safe, effective and comprehensive mapping using vessel-based technologies. This paper and presentation discuss examples of ALB data types produced in recent years from ALB surveying of coralline and reef environments. In addition to uniform coverage for bathymetry over extensive coastal areas, the co-registered and integrated information includes seafloor laser reflectance, digital orthophotos, and derived seafloor classification charts and numerical terrain analyses.