Detailed and accurate charting of the sea bottom along coastlines is vital for environmental monitoring and remediation, shoreline construction, and coastal navigation. Each of these activities requires reliable depth data for planning and management purposes. However, sonar-equipped vessels conducting hydrographic surveys cannot navigate very shallow or rocky coastal areas or narrow inlets with high tidal ranges, and topographic airborne LiDAR mapping (ALM) systems cannot penetrate the water. Airborne LiDAR bathymetry (ALB) fills this gap: as a supplementary survey method, it provides a seamless transition between mapping the land and charting the sea.
Superstorm Sandy — technically, a post-tropical cyclone by the time it made landfall along the coastline of the United States on October 29 — affected 24 states, including the entire Eastern Seaboard from Florida to Maine, causing particularly severe damage in New Jersey and New York. Storm surges, made worse by the full moon, caused high tides to rise about 20 percent higher than normal and wreaked havoc along hundreds of miles of coastline. Its impact included widespreadflooding, erosion, and movement of millions of tons of coastal sediments with the extreme power of storm-driven water — thereby actually altering vast stretches of coastline.
In the wake of this devastation, dozens of federal, state, and local agencies, as well as many private companies, contributed to the response. A couple of weeks after the storm, the Joint Airborne LiDAR Bathymetry Technical Center of Expertise (JALBTCX) of the U.S. Army Corps of Engineers (USACE) flew its Coastal Zone Mapping and Imaging LiDAR (CZMIL) along several stretches of the northeast coast, collecting a consistent data set.