DOI: 10.5066/p97031ju
title: Topobathymetric elevation models of the upper Delaware River, USA - Version 1 - 10km tiles

description: This dataset includes topographic elevations (in meters) surrounding and bathymetric elevations within the upper Delaware River (USA). Bathymetric lidar data was acquired using the Experimental Advanced Airborne Research Lidar, version B. The EAARL-B is a successor instrument to the original EAARL bathymetric LiDAR sensor developed for mapping coral reef environments in clear water, but subsequently used in river mapping. Both the original EAARL and the EAARL-B are small footprint, full waveform digitizing, green wavelength (532nm) airborne laser scanners, capable of acquiring laser returns from submerged as well as subaerial topography. Improvements from the original sensor include increased sample density, increased pulse rate, enhanced deep and shallow bathymetry performance, and improved data processing hardware. The EAARL-B sensor differs from the original in a 10x laser power increase, and incorporation of three shallow water receiving channels, as well as a deep water receiving channel. The EAARL-B splits each generated laser pulse into 3 pulses that are spaced 1.6m apart across the 250 m flight track and 2.0 m along track when flown at the nominal altitude of 300m above ground level at 100 knots per hour. Lidar data acquired with the EAARL-B was processed using the Airborne Lidar Processing System (ALPS) purpose-built software to analyze waveforms (for shallow bathymetry, deep bathymetry, and topography), geo-reference laser pulses, filter the resulting point cloud for noise, and to export standard lidar data format files (LAS). Additional processing included editing the point clouds to remove water surface and volume returns, off-ground objects, and erroneous returns. Topographic lidar point clouds from the Pennsylvania PAMAP program collected outside of the river channel were merged with the EAARL-B point clouds to create a complete topobathymetric elevation model of the active river area and riparian zone. Areas where the EAARL-B bathymetric lidar failed to map the river bottom (voids) were visually interpreted and the boundaries were digitized into a vector spatial data layer. Data is stored and processed in ALPS in 2 km x 2km tiles, organized into larger 10 km x 10 km tiles. The EAARL-B sensor was flown out of Salisbury, MD by the sensor developer (C. Wayne Wright) using USGS-owned, fixed-wing aircraft. Flights were conducted November 26, 28, and 29, and December 6, 14 and 20, 2012. Each flight day included multiple passes over a section of the river, and each river section may have been flown on multiple days, resulting in densifying the data collection over the entire river area flown, however, some river sections may have been flown with more over-passes than others. In total, over 200 river miles were surveyed (from Trenton, NJ to the reservoirs on the East and West Branch Delaware River), however, the data presented herein focuses only on the 122-river mile stretch between Hancock, NY, and Portland, PA. Cooperators: USGS Leetown Science Center, USGS Coastal and Marine Geology Program, USGS Earth Resources Science Center, USGS DOI WaterSmart Program, NPS Delware Water Gap National Recreation Area, NPS Upper Delware Scenic and Recreational River, Pennsylvania Natural Heritage Program