Dewberry has been selected to collect, process, and assess airborne topographic lidar data for Hillsborough County, Florida, covering approximately 1,200 square miles within the Southwest Florida Water Management District (SWFWMD).

Dewberry performed airborne topographic lidar mapping for this project in early 2017 using the new, fully integrated and calibrated Dual Channel Airborne Mapping System Riegl VQ-1560i sensor. The VQ-1560i's laser pulse repetition rate provides more than 1.3 million measurements per second on the ground and offers data acquisition at a wide range of point densities, making it ideal for aerial surveys of ultra-wide areas and complex urban environments.

Data were acquired at an average of 24 points per square meter, at an altitude of 4,300 feet above ground level, with 60 percent overlap. "In order to meet the stringent accuracy and point density requirements for this project, Dewberry elected to lease the Riegl VQ-1560i sensor," said Amar Nayegandhi, the firm's vice president and principal-in-charge for this project. "Our sensor selection and flight plan for this project was key to obtaining bare-earth elevations under dense mangroves and other evergreen canopies in Hillsborough County. Our goal is to provide SWFMWD, the county, and the City of Tampa with the highest-quality lidar dataset to be used in a myriad of applications."

"SWFWMD has a responsibility to maintain the balance between the water needs of current and future residents, while protecting and maintaining the natural systems that provide the water supply," noted Alvan Karlin, senior GIS scientist with the mapping and GIS division at SWFWMD. "This high-resolution data will enable the district to perform hydrologic and hydraulic modeling to meet the increased demands of the growing population in the county."

The firm will deliver point cloud lidar data with classified ground, building rooftops, and all overpasses and bridges; a hydrologically enforced digital terrain model; three-dimensional breaklines; and all associated metadata.