Data Management Plan

These data were collected by Leading Edge Geomatics using a RIEGL VQ880-G / RIEGL VQ880-GII topobathymertic lidar system. The data were acquired from November 22, 2019 to December 20, 2019. The data include topobathy data in LAS 1.4 format classified as created, unclassified (1); ground (2); noise (low or high) (7); bathymetric bottom (40); water surface (41); derived water surface (42); submerged object (43); no bathymetric bottom found (45); and temporal (46) in accordance with project specifications. The project was delivered in two blocks:

Block 1: The project consists of approximately 311 square miles of data within the Tampa Bay inlet, to include Old Tampa Bay, Hillsborough Bay and the Interbay Peninsula. This dataset contains 883 1000 m x 10000 m lidar tiles. The Block 1 delivery consists of 419 tiles for the eastern half of the AOI.

Block 2: The project consists of approximately 311 square miles of data within the Tampa Bay inlet, to include Old Tampa Bay, Hillsborough Bay, and the Interbay Peninsula. This dataset contains 905 1000 m x 1000 m lidar tiles. The Block 2 delivery consists of 486 tiles for the western half of the AOI.

Process Steps:

• 2020-09-01 00:00:00 - Data for the Tampa Bay North Topo-Bathymetry Mapping Project was acquired by Leading Edge Geomatics using a RIEGL VQ880-G / RIEGL VQ880-GII topobathymertic lidar system. All delivered lidar data is referenced to: Horizontal Datum-NAD83 (2011) epoch: 2010 Projection-UTM Zone 17 North Horizontal Units-meters Vertical Datum-NAD83 (2011) Vertical Units-meters Both green lidar data and NIR lidar data were acquired. Leading Edge Geomatics acquired, calibrated and performed the refraction correction to the lidar data. Dewberry received the calibrated green and NIR data and verified complete coverage. Relative accuracy of the green swaths compared to overlapping and adjacent green swaths as well as the relative accuracy of green swaths compared to overlapping and adjacent NIR swaths were verified through the use of Delta-Z (DZ) orthos created using LASTools. Intraswath or within a swath relative accuracy was also verified using LASTools. Profiles of elevated planar features, such as roofs, were used to verify horizontal alignment between overlapping swaths. Dewberry then verified absolute vertical accuracy of the swath data prior to full-scale production. Dewberry used algoritms in TerraScan to create the intial ground/submerged topography surface. Dewberry used rasterized aggregate extents of refracted points to create automated, smoothed 2-D refraction extent vectors with LAStools and ArcGIS. Light travels at different speeds in air versus water and its speed and direction of travel change when it enters the water column. The refraction correction process accounts for this difference by adjusting the depth (distance traveled) and horizontal position (change of angle/direction) of the lidar points acquired within water. These refraction extents delineate areas where the refraction correction was applied to the lidar data by Riegl's automated refraction correction software based on the software's detection of water. All lidar data was peer-reviewed. Dewberry's QAQC also included creating void polygons for use during review. All necessary edits were applied to the dataset. In-house software was used to update LAS header information, including all projection and coordinate reference system information. The final lidar data are in LAS format 1.4 and point data record format 6. The final classificaton scheme is as follows: 0-Created, never classified 1-Unclassified 2-Ground 7-Noise 40-Bathymetric bottom 41-Water surface 42-Derived water surface 43-Submerged object, not otherwise specified 45-No bottom found 46-Temporal All data was then verified by an independent QC department within Dewberry. The independent QC was performed by analysts who do not perform manual classification or editing. The independent QC involved quantitative and qualitative reviews.
• 2020-09-01 00:00:00 - Digital elevation models were created using only ground (2) and submerged topography (40) lidar point data. A triangulated irregular network (TIN) was generated from these data and rasterized at a 1-m spatial resolution using LAStools 'blast2dem' utility. Using ESRI ArcMap, void polygons representing areas of extremely sparse or non-existent bathymetric coverage were used to eliminate large areas of interpolation in the DEM. The void polygon creation process is described in the void polygon metadata and final project report. The DEM was clipped to the tile grid to create individual tiled DEMs and named according to project specifications. A confidence layer has been created and provided to NOAA as part of the deliverables. The confidence layer is a raster product in IMG format with 1 meter square pixels. The confidence layer provides a standard deviation value for every pixel by calculating the standard deviation of all ground and/or submerged topography lidar points that are located within a single pixel. The confidence layer pixels align to the pixels in the topobathy DEMs. The confidence layer can be displayed by unique values or classified into desired bins/ranges for analysis over larger areas.
• 2021-04-20 00:00:00 - The NOAA Office for Coastal Management (OCM) received DEM files from Dewberry. Horizontal positions were provided in UTM Zone 17 NAD83(2011), meters coordinates. Vertical positions were provided in NAVD88 (Geoid18) elevations and in meters. OCM performed the following processing for data storage and Digital Coast provisioning purposes: 1. The projection and vertical datum EPSG codes were assigned.. 2. The data were copied to https

Data is available online for bulk or custom downloads

Data is backed up to tape and to cloud storage.