Regional Mapping of the Coastal Zone with Airborne LIDAR
CORP OF ENGINEERS MOBILE AL JOINT AIRBORNE LIDAR BATHYMETRY TECHNICAL CENTER OF EXPERTISE
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Recent advancements in lidar sensors now allow for near-synoptic, regional-scale mapping of the coastal zone. One such sensor is the U.S. Army Corps of Engineers SHOALS Scanning Hydrographic Operational Airborne Lidar Survey system. SHOALS is unique in that it is the only lidar sensor, worldwide, that simultaneously collects bathymetry and adjacent topography. Because of SHOALS high collection rate, data density, and system accuracy, it is now cost effective to quantify regional coastal geomorphology and to better engineer management solutions on a regional scale. This article presents the SHOALS survey collected in Hawaii and discusses the value of lidar mapping to the coastal zone management community. SHOALS uses a scanning, pulsing laser to deliver light at two frequencies blue-green and infrared. While the infrared pulse provides a direct ranging of the water surface, the blue-green pulse penetrates the water column to provide direct ranging of the sea bottom. Two- or three-dimensional positioning of the SHOALS aircraft is from differential GPS or kinematic GPS, respectively. In addition to depth measurements, the SHOALS system simultaneously measures adjacent shoreline topography by directly ranging the terrain with its blue-green laser. The ability to map the entire coastal zone from the dry beach through the nearshore reveals linkages between nearshore and upland processes, such as the influence of changes in nearshore bathymetry on the shape of the shoreline. For regional coastal zone management surveys, SHOALS collects individual soundings every 8 meters and surveys at a rate of 400 soundings per second, or 25 sq km per hour. The accuracy of the soundings conforms to IHO Standards, or - 3 m in the horizontal and - 15 cm in the vertical.
- Physical and Dynamic Oceanography
- Infrared Detection and Detectors
- Ultraviolet Detection and Detectors