Christine J. Kranenburg
C. Wayne Wright
Emily S. Klipp
20160510
Uncalibrated EAARL-B Submerged Topography--Fort Lauderdale, Florida, 2014 (WGS84)
first
vector digital data
U.S. Geological Survey Data Release
doi:10.5066/F79S1P4S
St. Petersburg, FL
U.S. Geological Survey
https://doi.org/10.5066/F79S1P4S
Binary point-cloud data of a portion of the submerged environs of Fort Lauderdale, Florida, were produced from remotely sensed, geographically referenced elevation measurements by the U.S. Geological Survey (USGS). Elevation measurements were collected over the area using the second-generation Experimental Advanced Airborne Research Lidar (EAARL-B), a pulsed laser ranging system mounted onboard an aircraft to measure ground elevation, vegetation canopy, and coastal topography. The system uses high-frequency laser beams directed at the Earth's surface through an opening in the bottom of the aircraft's fuselage. The laser system records the time difference between emission of the laser pulse and the reception of the reflected laser signal in the aircraft. The plane travels over the target area at approximately 60 meters per second at an elevation of approximately 300 meters, resulting in a laser swath of approximately 240 meters with an average point spacing of 0.5-1.6 meters. The EAARL, developed originally by the National Aeronautics and Space Administration (NASA) at Wallops Flight Facility in Virginia, measures ground elevation with a vertical resolution of 3 centimeters. A peak sampling rate of 15-30 kilohertz results in an extremely dense spatial elevation dataset. Over 100 kilometers of coastline can be surveyed easily within a 3- to 4-hour mission. When resultant elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding land development.
The purpose of this project was to collect data suitable for deriving the depth calibration function and coefficients of EAARL-B data. To ensure that St. Petersburg Coastal and Marine Science Center (SPCMSC) data management protocols were followed, this survey was assigned a USGS field activity number (FAN), 2014-304-FA. Additional survey and data details are available at http://cmgds.marine.usgs.gov/fan_info.php?fan=2014-304-FA
Raw lidar data are not in a format that is Nonely usable by resource managers and scientists for scientific analysis. Converting dense lidar elevation data into a readily usable format without loss of essential information requires specialized processing. The USGS's Coastal and Marine Geology Program (CMGP) has developed custom software to convert raw lidar data into a GIS-compatible map product to be provided to GIS specialists, managers, and scientists. The primary tool used in the conversion process is Airborne Lidar Processing System (ALPS), a multi-tiered processing system developed originally by a USGS-NASA collaborative project. Specialized processing algorithms are used to convert raw waveform lidar data acquired by the EAARL-B to georeferenced spot (x,y,z) returns for "first surface" and "bare earth" topography. The terms first surface and bare earth refer to the digital elevation data of the terrain, but while first-surface data include vegetation, buildings, and other manmade structures, bare-earth data do not. The zero crossing of the second derivative (that is, detection of stationary points) is used to detect the first return, resulting in "first surface" topography, while the trailing edge algorithm (that is, the algorithm searches for the location prior to the last return where direction changes along the trailing edge) is used to detect the range to the last return, or "bare earth" (the first and last returns being the first and last significant measurable portion of the return pulse). First and last returns, in the context of submerged topography data, produce an elevation map of the surface of the water and the seafloor, respectively. Statistical filtering, known as the Random Consensus Filter (RCF), is used to remove false bottom returns and other outliers from the EAARL-B topography data. The filter uses a grid of square cells (buffer) of user-defined size overlaid onto the original point cloud. The user also defines the vertical tolerance (vertical width) based on the topographic complexity and point-sampling density of the data. The maximum allowable elevation range within a cell is established by this vertical tolerance. An iterative process searches for the maximum concentration of points within the vertical tolerance and removes those points outside of the tolerance (Nayegandhi and others, 2009). Please note that these data are not suitable for navigational use, nor for determining absolute elevation measurements. Submerged topography was assigned to Class 29.
20140421
20140422
ground condition
None planned
-80.1213
-80.0848
25.9821
25.9097
USGS Metadata Identifier
USGS:b4a00738-b72a-4f18-99e9-f6670808127e
ISO 19115 Topic Category
elevation
None
Airborne Lidar Processing System
ALPS
Cessna 310
Digital Elevation Model
DEM
EAARL-B
Experimental Advanced Airborne Research Lidar
laser hydrography
South Florida Testing Facility
Global Change Master Science Directory
LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION
OCEAN > BATHYMETRY/SEAFLOOR TOPOGRAPHY > SEAFLOOR TOPOGRAPHY
OCEAN > COASTAL PROCESSES > COASTAL ELEVATION
OCEAN > COASTAL PROCESSES > SHORELINE DISPLACEMENT
DOI/USGS/CMG > COASTAL AND MARINE GEOLOGY, U.S. GEOLOGICAL SURVEY, U.S. DEPARTMENT OF INTERIOR
GCMD Instrument
LIDAR > LIGHT DETECTION AND RANGING
Data Categories for Marine Planning
distributions
bathymetry and elevation
Marine Realms Information Bank (MRIB) Keywords
altimetry
topographic mapping
USGS Thesaurus
lidar
remote sensing
topography
digital elevation models
Geographic Names Information System
Fort Lauderdale
Florida
Atlantic Ocean
None
Submerged
None
2014
None
The U.S. Geological Survey requests to be acknowledged as originator of these data in future products or derivative research.
Christine Kranenburg
Cherokee Nation Technologies, U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL
Computer Scientist
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
727 502-8129
727 502-8182
ckranenburg@usgs.gov
M-F, 8:00-4:00 ET
Acknowledgment of the USGS, St. Petersburg Coastal and Marine Science Center, as a data source would be appreciated in products developed from these data, and such acknowledgment as is standard for citation and legal practices for data source is expected by users of this data. Sharing of new data layers developed directly from these data would also be appreciated by the USGS staff. Users should be aware that comparisons with other datasets for the same area from other time periods may be inaccurate due to inconsistencies resulting from changes in photointerpretation, mapping conventions, and digital processes over time. These data are not legal documents and are not to be used as such.
Unclassified
Unclassified
None
Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.3.1.4959
Nayegandhi, A., Brock, J.C., and Wright, C.W.
2009
Small footprint, waveform-resolving lidar estimation of submerged and subcanopy topography in coastal environments
International Journal of Remote Sensing
v. 30 no. 4, p. 861-878
https://doi.org/10.1080/01431160802395227
Wright, C.W., Kranenburg, C.J., Troche, R.J., Mitchell, R.W., and, Nagle, D.B.,
2016
Depth calibration of the experimental advanced airborne research lidar, EAARL-B
U.S. Geological Survey Open-File Report
2016–1048
https://doi.org/10.3133/ofr20161048
Wright, C.W., Kranenburg, C., Battista, T.A., and Parrish, C.
2016
Depth calibration and validation of the Experimental Advanced Airborne Research Lidar, EAARL-B
Journal of Coastal Research
Special Issue, No. 76, pp. 4–17
https://doi.org/10.2112/SI76-002
The expected accuracy of the measured variables is as follows: attitude within 0.05 degree; 3 centimeters nominal ranging accuracy. Vertical accuracy of bathymetric data is depth-dependent and is assessed relative to International Hydrographic Organization Standards defined in International Hydrographic Bureau, 2008, IHO Standards for Hydrographic Surveys (5th ed.): International Hydrographic Organization Special Publication No. 44, 36 p. [Available at
http://www.iho.int/iho_pubs/standard/S-44_5E.pdf.]. Quality checks are built into the data-processing software.
The data coverage area specified for this project was processed without known issues.
These point-cloud data may appear sparse or nonexistent, which is a result of automated filtering, removal by manual editing or lack of survey coverage.
Raw elevation measurements have been determined to be within 1 meter in horizontal accuracy.
As expected, the Total Vertical Uncertainty (TVU) of this uncalibrated data does not meet the IHO minimum standards for hydrographic surveys for depths greater than 10 m. Refer to USGS Open-File Report 2016-1048 for a detailed explanation of the methods used to assess vertical accuracy. Vertical accuracies may vary based on the type of terrain, satellite configuration and the accuracy of the GPS and aircraft-attitude measurements.
The data were collected using a Cessna 310 aircraft. The EAARL-B laser scanner collects the data using a green-wavelength (532-nanometer) raster scanning laser, while a digital camera acquires a visual record of the flight. The data are stored on hard drives and archived at the USGS office in St. Petersburg, Florida. The navigational data were processed and then, along with the raw data, were downloaded into ALPS (20140715). Data were converted from units of time to x,y,z points for elevation, which were then filtered, manually edited and quality checked to ensure anomalies and noise were addressed to specification. The input parameters for the RCF were: grid cell size (buffer) = 1000 cm x 1000 cm; vertical tolerance (vertical width) = 100 cm; minimum number of points for consensus = 3; overlap factor = 4.
20150319
Christine Kranenburg
Cherokee Nation Technology, U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL
Computer Scientist
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
727 502-8129
ckranenburg@usgs.gov
M-F, 8:00-4:00 ET
ALPS exported the WGS84 submerged topography from .pbd format to a LAS file. LAStools was used to compress the LAS file into a LAZ file.
20160223
Christine Kranenburg
Cherokee Nation Technology, U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL
Computer Scientist
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
727 502-8129
ckranenburg@usgs.gov
M-F, 8:00-4:00 ET
Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog.
20170104
U.S. Geological Survey
Alan O. Allwardt
Contractor -- Information Specialist
mailing and physical address
2885 Mission Street
Santa Cruz
CA
95060
831-460-7551
831-427-4748
aallwardt@usgs.gov
Added keywords section with USGS persistent identifier as theme keyword.
20201013
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
Point
Universal Transverse Mercator
17
0.999600
-81.000000
0.000000
500000.000000
0.000000
coordinate pair
0.01
0.01
meters
World Geodetic System 1984 (G1674)
WGS_1984
6378137.000000
298.257223563
World Geodetic System 1984
0.01
meters
Explicit elevation coordinate included with horizontal coordinates
This file consists of uncalibrated submerged topography elevation data available for this survey. Data were processed via using ALPS software. Data were quality controlled through the application of the RCF, manual editing in ALPS, and inspection in Global Mapper. Submerged topography was assigned to Class 29.
http://pubs.usgs.gov/of/2009/1078/
U.S. Geological Survey
Christine Kranenburg
Computer Scientist
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
727 502-8129
M-F, 8:00-4:00 ET
FLA2014_EAARLB_FLL_Uncalibrated_ST_z17_wgs84_mosaic.laz
Although these data have been processed successfully on a computer system at the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system, or for None or scientific purposes, nor shall the act of distribution constitute any such warranty. The USGS shall not be held liable for improper or incorrect use of the data described and/or contained herein. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
BINARY
1.2
ASPRS LAS
https://coastal.er.usgs.gov/data-release/doi-F79S1P4S/data/FLA2014_EAARLB_FLL_Uncalibrated_ST_z17_wgs84_mosaic.zip
None
Contact U.S. Geological Survey.
Vary
Contact U.S. Geological Survey for details.
20201013
Christine Kranenburg
Cherokee Nation Technology Solutions, U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL
Computer Scientist
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
727 502-8129
ckranenburg@usgs.gov
M-F, 8:00-4:00 ET
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998
local time