Quantum Spatial, Inc.
20190329
Task Name: Florida Gulf Coast Topobathy LiDAR 2018 D19 GDD
USGS Contract: G16PC00016, Task Order: 140G0219F0002-FL
vector digital data
Product: Breakline data is used to hydro-flatten the DEMs created for the Florida Gulf Coast Topobathymetric LiDAR 2018 lidar project.
Geographic Extent: This dataset and derived products encompass an area covering approximately 471 square kilometers of south Florida, Louisiana, and Alabama.
Dataset Description: RAW flight line swaths were processed to create 2,272 classified LAS 1.4 files delineated in 500 m x 500 m tiles. Each LAS file contains LiDAR point information, which has been calibrated, controlled, and classified. Additional derived products include green and NIR intensity images, hydro-flattened DEMs, interpolated and clipped topobathymetric DEMs, and highest hit surface models of the study area. Ground Control Points were acquired and calibrated by Quantum Spatial, Inc.
Data acquisition was coordinated by Quantum Spatial and all lidar data calibration, and follow-on processing were completed by Quantum Spatial
Ground Conditions: Acquisition below aircraft free of smoke, fog and cloud cover.
The purpose of the lidar data was to produce a high accuracy 3D dataset that meets all necessary standards laid out by the 3DEP initiative.
The raw lidar point cloud data were used to create classified lidar LAS files, NIR and Green Scanner intensity images, hydro-flattened DEMs, clipped and unclipped topobathymetric DEM's, highest hit surface models, and 3D breaklines of tidal water bodies and lakes within the study area.
Breakline File Type = SHP
Breakline Elevation Units = Meters
Downhill Treatment Applied = Monotonic
Type of Hydro Treatment Required = Hydro-flattened
20181027
20181103
ground condition
None Planned
-88.931828
-86.512003
30.411465
29.731995
314408.753300
546871.473200
3364380.425000
3290630.581700
none
breakline
remote sensing
Elevation data
lidar
Hydrology
none
Florida
Louisiana
Alabama
No restrictions apply to these data.
None. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of its limitations. Acknowledgement of the U.S. Geological Survey would be appreciated for products derived from these data.
Data covers the entire area specified for this project. Breaklines were collected for all shorelines and in all inland ponds and lakes ~2 acres or greater. These features were flat and level water bodies at a single elevation for each vertex along the bank. The entire water surface edge is at or below the immediate surrounding terrain.
All files are inspected to ensure that they conform to the specified file naming conventions, all files load in their correct geographic position, all files conform to the project specifications for file standards and content.
Hydro-flattening Breaklines and Hydro-flattened DEM creation: Water boundary polygons were developed using an algorithm which weights LiDAR-derived slopes, intensities, and return densities to detect the water's edge. The water's edge was then manually reviewed and edited as necessary. Elevations were assigned to the water’s edge through neighborhood statistics identifying the lowest LiDAR return from the water surface. Lakes were assigned a consistent elevation for an entire polygon and tidal areas were flattened in sections. These breaklines were incorporated into the hydro-flattened DEM by enforcing triangle edges (adjacent to the breakline) to the elevation values derived from the breakline. This implementation corrected interpolation along the hard edge.
20190328
Hydroflattening Breaklines, Hydroflattened DEM
Vector
Universal Transverse Mercator
16
0.99960000
-87.00000000
0.00000000
500000.00000000
0.00000000
coordinate pair
0.01
0.01
Meters
North American Datum of 1983(2011)
Geodetic Reference System 80
6378137.0
298.257223563
North American Vertical Datum of 1988 Geoid12B
0.01
Meters
Explicit elevation coordinate included with horizontal coordinates
20190329
Quantum Spatial, Inc.
mailing and physical
1100 NE Circle Blvd, Suite 126
Corvallis
OR
97330
USA
541-752-1204
FGDC Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998