United States Geological Survey Florida Integrated Science Center
2007
EAARL Submarine Topography-Northern Florida Keys Reef Tract
First
remote-sensing image
USGS Open File Report
OFR 2007-1432
FISC St. Petersburg
USGS
The USGS, in cooperation with the National Park Service (NPS) and the National Aeronautics and Space Administration (NASA), provide the coastal management community with digital elevation products. The USGS processes aircraft lidar data provided by NASA, develops software tools and algorithms to use and analyze the data, and makes products available to the coastal management community.
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st_e578_n2792_z17ed2.tif
Lidar is a remote sensing technique that uses laser light to detect, range, or identify remote objects based on light reflected by the object or emitted through its subsequent fluorescence. Airborne ranging lidar is now being applied in coastal environments to produce accurate, cost-efficient elevation datasets with high spatial density. The USGS, in cooperation with NASA and NPS, is using airborne lidar to measure the submerged topography of the Northern Florida Keys Reef Tract (NFKRT); secondarily, the data will be assessed for its potential in terms of benthic characterization. Elevation measurements were collected over the NFKRT using the NASA Experimental Advanced Airborne Research Lidar (EAARL), a pulsed laser ranging system mounted onboard an aircraft to measure subaerial and submarine topography. The system uses a high frequency laser beam 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 beam and the reception of the reflected laser signal in the aircraft. The EAARL system, developed by the NASA Wallops Flight Facility (WFF) in Virginia, measures ground elevation with a vertical resolution of roughly 15 centimeters. A sampling rate of up to 3 kHz results in an extremely dense spatial elevation data set. The EAARL system is typically flown at 300 m altitude AGL, resulting in a 240 m swath for each flightline. Data collection occurred with approximately 50% overlap between flightlines, resulting in about one laser sounding per square meter. The data were processed by the USGS, Florida Integrated Science Center (FISC] St. Petersburg office to produce 1 meter resolution raster images that can be easily ingested into a Geographic Information System (GIS). The data were organized as 2 km by 2 km data tiles in 32 bit floating-point integer GeoTIFF format.
One objective of this research is the creation of techniques for the surveying of submerged topography for the purposes of habitat mapping, ecological monitoring, change detection, and event assessment (e.g., hurricanes and extreme storm events). As part of this project, data from NASA EAARL were used. This sensor has the potential to make significant contributions in this realm for measuring shallow water depth and conducting cross-environment surveys. High spectral resolution and low costs were found to be key factors in providing accurate and affordable imagery to managers of coastal tropical habitats.
Raw lidar data is not in a format that is generally usable by Park Service 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 converts raw lidar data into a GIS-compatible map product to be provided to NPS 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 by a USGS/NASA collaborative project for the generation of subaerial and submarine lidar topographic products. Specialized processing algorithms are used to convert raw waveform lidar data acquired by the EAARL to geo-referenced spot (x,y,z) returns for submarine topography. These data are then converted to the North American (Horizontal ) Datum of 1983 (NAD83) and the North American Vertical Datum of 1988 (NAVD88, using the Geoid 03 model). The final products are 2x2-km map tiles written out in a standard GeoTIFF format with associated metadata information. These tiles are created for visual interpretation and regional quantitative analysis. Metadata files include the standard FGDC format.
en
July 10-14, 2001September 4-7, 2001August 2-9, 2002REQUIRED: The year (and optionally month, or month and day) for which the data set corresponds to the ground.
ground condition
As needed
-80.225626-80.20564425.24228625.224112
578001.000000580002.0000002790000.0000002792001.000000
None
Lidar, Experimental Advanced Airborne Research Lidar, digital elevation model, elevation change, laser altimetry, derived surface, coastal resource management, Airborne Lidar Processing System, benthic cover types, submarine elevations
None
Northern Florida Keys Reef Tract
Florida
Florida Keys
United States East Coast
submarine topography
Any use of these data signifies a user's agreement to comprehension and compliance of the USGS Standard Disclaimer. Ensure all portions of metadata are read and clearly understood before using these data in order to protect both user and USGS interests. See section 6.3 Distribution Liability.
Although the USGS is making these data sets available to others who may find the data of value, USGS does not warrant, endorse, or recommend the use of these data for any given purpose. The user assumes the entire risk related to the use of these data. These data sets are not for navigational purposes. USGS is providing these data "as is", and USGS disclaims any and all warranties, whether expressed or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose. In no event will USGS be liable to you or to any third party for any direct, indirect, incidental, consequential, special, or exemplary damages or lost profits resulting from any use or misuse of these data.
Acknowledgement of the U.S. Geological Survey FISC - St. Petersburg as a data source would be appreciated in products developed from these data, and such acknowledgement as is standad for citation and legal practices for data source is expected by users of this data set. Sharing new data layers developed directly from these data would also be appreciated by USGS staff. Users should be aware that comparisons with other data sets for the same area from other time periods may be inaccurate due to inconsistencies resulting from changes in photo interpretation, mapping conventions, and digital processes over time. These data are not legal documents and are not to be used as such.
United States Geological Survey, Florida Integrated Science Center
Dr. John C. Brock
Research Oceanographer
mailing and physical address
600 4th Street South
St. Petersburg
Florida
33701
USA
(727) 803-8747 ext3088
(727) 803-2031
jbrock@usgs.gov
8am to 5pm M-F EST
The USGS Florida Integrated Science Center, St. Petersburg, FL would like to acknowledge NASA Goddard Space Flight Center and the National Park Service for their cooperation and assistance in the aquisition and processing of the data. The National Park Service also contributed by cleaning the LIDAR dataset in preparation for map production.
Unclassified
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.1.1332
Brock, J.C.; Wright, C.W.; Sallenger, A.H; Krabill, W.B., and Swift
Basis and Methods of NASA Ariborne Topographic Mapper Lidar Surveys for Coastal Studies
journal article
West Palm Beach, FL
Journal of Coastal Research
Miami, FL
Proceedings of the Seventh International Conference on Remote Sensing for Marine and Coastal Environments
Wright, C.W. and Brock, J.C.
EAARL: A lidar for mapping shallow coral reefs and other coastal environments
Proceedings Article
Miami, FL
Proceedings of the Seventh International Conference on Remote Sensing for Marine and Coastal Environments
John Brock and Asbury Sallenger
Airborne Topographic Lidar Mapping for Coastal Science and Resource Management
USGS Open File Report
St. Petersburg
U.S. Geological Survey
Nayegandhi, A., Brock, J.C., Wright, C.W., OConnell, M.O., 2006
Evaluating a small-footprint, waveform-resolving lidar over coastal vegetation communities
USGS Open File Report
2006-12:1408-1417
Photogrammetric Engineering and Remote Sensing
Raster Dataset
The expected accuracy of the measured variables are as follows: attitude within 0.07 degree, 3-cm nominal ranging accuracy, and vertical elevation accuracy of +/-20 cm for the submerged surface. Quality checks are built into the data-processing software.
Several regions of the dataset are labeled as "No Data", which corresponds to a cell value of -100 m in the GeoTiff file. These "No Data" areas are a result of the survey not covering a particular region, optical water depth of greater than 1.5 Secchi disc depths, or the manual removal of lidar processing artifacts.
Raw elevation measurements have been determined to be within 1 meter horizontal accuracy. Processing steps (grid interpolation) may introduce additional error which has not been tested at the time of this publication.
1
Elevations of the DEM are vertically consistent with the point elevation data, +/-20 cm.
.20
Point elevation measurements collected by the EAARL sensor.
July 10-14, 2001September 4-7, 2001August 2-9, 2002
ground condition
The data are collected using a NOAA DeHavilland Twin Otter aircraft. The NASA Experimental Advanced Airborne Research Lidar (EAARL) laser scanner collects the data using a green (532nm) 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 and the NASA office at Wallops Flight Facility. The navigational data are processed at Wallops Flight Facility. The navigational and raw data are then downloaded into the Airborne Lidar Processing System (ALPS). Data are converted from units of time to x,y,z points for elevation. The derived surface data can then be converted into raster data (geotiffs).
United States Geological Survey, Florida Integrated Science Center
Amar Nayegandhi
Computer Scientist
mailing and physical address
600 4th Street South
St. Petersburg
Florida
33701
USA
727-803-8747
8am to 5pm M-F EST
Call Survey for Details
The raster dataset was opened in ERDAS IMAGINE for editing. An Area of Interest (AOI) polygon was drawn around regions of poor data quality. Poor data quality was determined visually by locating gaps in the data as well as artifacts of the Lidar processing. Pixels within the AOI polygons were given a raster value of -100 to correspond with other areas of No Data.
National Park Service South Florida / Caribbean Network
mailing and physical address
18001 Old Cutler Road, Suite 419
Palmetto Bay
FL
33157
USA
(305) 252-0347
mailing and physical address600 4th Street SouthSt. PetersburgFL338701USAUSGS, FISC St. Petersburg727-803-8747Metadata imported into ArcCatalog from XML file.20070830
Raster
Pixel
2001
2001
1
1.0000001.00000032Upper LeftFALSENone1pixel RGBTRUE
row and column
1.000000
1.000000
meters
Universal Transverse Mercator170.999600-81.0000000.000000500000.0000000.000000
North American Datum of 1983
Geodetic Reference System 80
6378137.000000
298.257222
NAD_1983_UTM_Zone_17NGCS_North_American_1983
Geotiff
This Digital Elevation Model is a Geotiff derived from point data. It is raster data consisting of cells. Each cell has an elevation value associated with it. Cell size is 1 meter by 1 meter.
This Digital Elevation Model is a GeoTIFF derived from point data referenced to WGS84, NAD83 UTM eastings and northings (m). The variables measured by EAARL are: distance between aircraft and GPS satellites (m), attitude information (roll, pitch, heading in degrees), scan angle (degrees), second of the epoch (sec), and 1-ns time-resolved return intensity waveform (digital counts). It is raster data consisting of cells. Each cell has an elevation value associated with it. Cell size is 1 meter by 1 meter.
United States Geological Survey, FISC St. Petersburg
mailing and physical address
600 4th Street South
St. Petersburg
Florida
33701
USA
727-803-8747 ext3049
(727) 803-2031
8am to 5pm M-F EST
EAARL Submarine Topography-Florida Keys National Marine Sanctuary
Open File Report 2007-1432
The United States Geological Survey shall not be held liable for improper or incorrect use of the data described and/or contained herein. These data and related graphics are not legal documents and are not intended to be used as such.
TIFF
January 2007
Geotiff
0.000
0.000
DVD
0
Call USGS for Details
Call USGS for Details
July 10-14, 2001Sept. 4-7, 2001August 2-9, 2002
20070831
United States Geological Survey, FISC St. Petersburg
REQUIRED: The person responsible for the metadata information.
mailing and physical address
600 4th Street South
St. Petersburg
Florida
33701
USA
727-803-8747
(305) 253-0463
8am to 5pm M-F EST
FGDC Content Standards for Digital Geospatial Metadata
FGDC-STD-001-1998
local time
None
None
http://www.esri.com/metadata/esriprof80.html
ESRI Metadata Profile
enhttp://www.esri.com/metadata/esriprof80.htmlESRI Metadata Profile
20070904091457002007090409145400FALSE{2AD7F273-BAB1-47E5-B034-0D578A2A42A3}200709040914570020070808