Mobile Lidar Integrated with a 360-Degree Spherical Camera for Rapid Assessment of Beach and Foredune Elevation Change Due to Hurricane Hanna on North Padre Island, Texas, USA

Hurricane Hanna made landfall as a Category 1 hurricane on July 25, 2020 around 5 P.M. Central Time on Padre Island, Texas. This storm was the first of its kind in the 2020 Atlantic Hurricane Season, developing weeks before any other H-named storms in past seasons. Sustained winds were around 90 mph at the time of impact. By 6:50 A.M. 2.94 inches of rain were reported at Naval Air Station-Corpus Christi, near North Padre Island. Padre Island experienced substantial flooding and storm surge up to 6 feet in some areas. This project aims to detect elevation change along a stretch of beach on North Padre Island, Texas through post-storm data collection with a mobile lidar system (MLS) along with a 360-degree spherical camera. This study will utilize the HiWay Mapper system, which consists of the Snoopy mobile lidar as well as the Ladybug camera, both distributed by LidarUSA, to collect post-storm data. The sensor consists of a Velodyne HDL 32-E lidar, a NovAtel SPAN-IGM inertial navigation system (INS), and an onboard Novatel 702-GG Global Navigation Satellite System (GNSS) receiver. The Velodyne collects about 700,000 points per second, has a +/- 2 cm accuracy at 25 m, has a 100 m range, and is considered as a lower cost, shorter range lidar. The FLIR Ladybug5+ is a 360-degree spherical camera that collects 90% of a full sphere at an accuracy of 2 mm at 10 m distance. Georeferenced ground control points will be used to determine the accuracy of the Snoopy system and will be integrated in the post-processing procedures as needed. The data will be compared with prior surveys completed with Mobile Lidar and/or airborne lidar collected as routine surveys. Results will be reported using both elevation change and relative volume change, including sediment erosion and deposition in the beach and foredunes. System accuracy with and without control points will be presented with applications in a coastal environment and will be included as part of a "best methods" procedure for using the Snoopy system. The 360-degree camera will be used to colorize in the coastal scan for further analyses.