Fugro was contracted in July 2017 by the State of Maine Department of Marine Resources (SMDMR), Maine Coastal Program (MCP), and the NOAA Office for Coastal Management (OCM) to conduct an Airborne LiDAR Bathymetry (ALB) survey in the vicinity of Blue Hill Bay in Maine, and to deliver fully processed and verified hydrographic survey data.The ALB survey was conducted with the SHOALS-1000T and Riegl VQ-820-G lidar systems in a concurrent acquisition. The SHOALS system, with a high power laser, provided the better probability for deep sounding detections at a reduced point density (about 0.15 pts/m2); whilst the VQ-820-Q provided high density coverage (up to 8.5 pts/m2) but at reduced depth detection.

This metadata record describes the bare earth, 2 meter digital elevation model (DEM) created from the topographic and bathymetric LiDAR elevations generated from data collected with the SHOALS-1000T LiDAR system along Blue Hill Bay on the coastline of Maine. Data were collected by Fugro for NOAA OCM. The SHOALS system is a bathymetric LiDAR sensor for use in coastal mapping and charting activities because the laser's ability to penetrate the water column and detect targets up to 2.5 times the Secchi disk depth. Survey coverage was based on a delimiting polygon provided by NOAA OCM, which envelopes the area between the 0 m contour (NAVD88) down to approximated -10 meters. An additional horizontal buffer of 100 meters from the 0 m contour expanded the survey area coverage to include the adjacent emerged topography. SHOALS data have been processed on Optech SHOALS-GCS and QPS Fledermaus software packages for: auto-processing; calibration, cleaning and editing, validation, basic classification, and exported to LAS format.

In addition to these bare earth Digital Elevation Model (DEM) data, the lidar point data that these DEM data were created from, are also available. These data are available for custom download at the link provided in the URL section of this metadata record.

A topographic and bathymetric reflectance raster are also available. These data are available for download at the link provided in the URL section of this metadata record.

A link to custom download the bare earth DEM that was created from the concurrently collected topographic and bathymetric data (collected with the Riegl VQ-820-G lidar system) is provided in the URL section of this metadata record.