United States Geological Survey
Center for Coastal and Watershed Studies
2006
merge_5.tif
First
remote-sensing image
Biscayne National Park USGS-NPS-NASA EAARL Submarine Topography
St. Petersburg, FL
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.
\\LIDAR1\C$\LIDAR\DRTO\LIDAR\merge_52\merge_5.tif
merge_5.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 it subsequent fluorescence. Airborne ranging lidar is now being applied in coastal environments to produce accurate, cost-efficient elevation datasets with high data density. The USGS in cooperation with NASA and NPS is using airborne lidar to measure the submerged topography of the north Florida reef tract; secondarily, the data will be assessed for its potential in terms of benthic characterization. Elevation measurements were collected over Biscayne National Park using the NASA Experimental Advanced Airborne Research Lidar (EAARL), a pulsed laser ranging system mounted onboard an aircraft to measure subaerial and submarine coastal topography. With the NASA EAARL lidar system, submarine data is generally acquired to a maximum of approximately 1.5 secchi depths (a measure of water clarity). 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 Experimental Advanced Airborne Research Lidar, developed by the National Aeronautics and Space Administration (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 Center for Coastal and Watershed Studies to produce 1meter 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 32bit floating-point integer GeoTIFF format.
One objective of this research is the creation of techniques for the surveying of coral reefs for the purposes of habitat mapping, ecological monitoring, change detection, and event assessment (e.g., bleaching, hurricanes, disease outbreaks, etc.). As part of this project, data from an innovative instrument developed at NASA Wallops Flight Facility, the NASA Experimental Airborne Advanced Research Lidar (EAARL), was used. This sensor has the potential to make significant contributions in this realm for measuring water depth and conducting cross-environment surveys. High spectral resolution, water-column correction, 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 National Park Service 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 use of subaerial and submarine lidar in coastal change assessment. Specialized processing algorithms are used to convert raw waveform lidar data acquired by the EAARL to georeferenced spot (x,y,z) returns for submarine topography. These data are then converted to the NAD83 horizontal and NAVD88 vertical datum (using the Geoid 99 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.
The flights over Biscayne National Park constituted the first survey of a coral reef ecosystem using the NASA EAARL instrument. An acquisition artifact, a subtle NW/SE striation perpendicular to the flight line, is present in some data tiles. Subsequent refinements in the acquisition and processing of the data have substantially reduced the presence of these artifacts in datasets derived from later surveys.
en
ground condition
Unknown
-82.997385
-82.757382
24.746290
24.544743
298001.000000322001.0000002716000.0000002738000.000000
None
LIDAR
Experimental Advanced Airborne Research Lidar
digital elevation model
elevation change
laser altimetry
derived surface
coastal resource management
submerged topography
Airborne Lidar Processing System
benthic cover types
bare earth elevations
None
Dry Tortugas National Park
Florida
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 Center for Coastal and Watershed Studies as a data source would be appreciated in products developed from these data, and such acknowledgement as is standard for citation and legal practices for data source is expected by users of this data. 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.
Dr. John C. Brock
United States Geological Survey, Center for Coastal and Watershed Studies
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
Monday-Friday, 8-5, EST
The USGS Center for Coastal and Watershed Studies would like to acknowledge NASA Goddard Space Flight Center for their cooperation and assistance in the development of the data. The National Park Service also contributed by editing the lidar tiles to remove processing artifacts.
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.722
Brock, J.C.; Wright, C.W.; Sallenger, A.H; Krabill, W.B., and Swift, R.N
2003
Basis and Methods of NASA Airborne Topographic Mapper Lidar Surveys for Coastal Studies
journal article
West Palm Beach, FL; Miami, FL; St. Petersburg, FL
Journal of Coastal Research, Proceedings of the Seventh International Conference on Remote Sensing for Marine and Coastal Environments, US Geological Survey
Wright, C.W. and J. Brock
2002
EAARL: A lidar for mapping shallow coral reefs and other coastal environments
20-22, May 2002
proceedings article
West Palm Beach, FL; Miami, FL; St. Petersburg, FL
Journal of Coastal Research, Proceedings of the Seventh International Conference on Remote Sensing for Marine and Coastal Environments, US Geological Survey
John Brock and Asbury Sallenger, US Geological Survey
2001
Airborne Topographic Lidar Mapping for Coastal Science and Resource Management
USGS Open File Report
West Palm Beach, FL; Miami, FL; St. Petersburg, FL
Journal of Coastal Research, Proceedings of the Seventh International Conference on Remote Sensing for Marine and Coastal Environments, US Geological Survey
Nayegandhi, A.; Brock, J.C.; Wright, C.W.; Clayton, T.D.; Mosher, L.A.
May 23-28, 2004
Processing and Filtering 'Bare Earth' Topographic Data Acquired by NASA's Experimental Advanced Airborne Research Lidar (EAARL)
CD-ROM
Published as Abstract and Presented at the ASPRS Annual Conference, Denver, CO, May 23-28, 2004. Proceedings on CDROM.
Nayegandhi, A.; Brock, J.C.; Wright C.W.
Small-footprint, waveform-resolving lidar estimation of submerged and sub-canopy topography in coastal environments.
In Preparation
In Preparation.
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 "first return" 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.
Elevations of the DEM are vertically consistent with the point elevation data, +/-20 cm.
The data are collected using a Cessna 310 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).
2002-2004
United States Geological Survey Center for Coastal and Watershed Studies
Amar Nayegandhi
Computer Scientist
mailing and physical address
600 4th Street South
St. Petersburg
Florida
33701-
USA
727-803-8747
8:00am to 5:00pm Monday thru Friday, EST
Call Survey for Details
After editing each lidar tile to remove inaccuracies from the dataset, each individual tile was opened in ArcGIS. The merge command was run in the raster calculator, which created a single combined tile that was exported as a new GeoTIFF.
March 2006
National Park Service South Florida / Caribbean Network Inventory and Monitoring Program
Judd Patterson
Research Assistant
mailing and physical address
18001 Old Cutler Road, Suite 419
Palmetto Bay
Florida
33157
United States
(305) 252-0347
(305) 253-0463
Raster
Pixel
4400
4800
1
5.0000005.00000032Upper LeftFALSENone1pixel RGBTRUETIFF
row and column
5.000000
5.000000
meters
Universal Transverse Mercator170.999600-81.0000000.000000500000.0000000.000000
North American Datum of 1983
Geodetic Reference System 80
6378137.000000
298.257222
GCS_North_American_1983NAD_1983_UTM_Zone_17N
North American Vertical Datum of 1988
.01
meters
Explicit elevation coordinate included with horizontal coordinates
This Digital Elevation Model is an 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 an 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
Jerry Butcher
Windows System Administrator
Mailing Address
600 4th Street South
St. Petersburg
FL
33701
USA
727-803-8747 ext3049
Dry Tortugas National Park Digital Map Atlas DVD
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.
The information contained in these data is dynamic and may change over time. The data are not better than the original sources from which they were derived. It is the responsibility of the data user to use the data appropriately and consistent within the limitations of geospatial data in general and these data in particular. The related graphics are intended to aid the data user in acquiring relevant data; it is not appropriate to use the related graphics as data.
The United States Geological Survey gives no warranty, expressed or implied, as to the accuracy, reliability, or completeness of these data. It is strongly recommended that these data are directly acquired from an USGS server and not indirectly through other sources which may have changed the data in some way. Although these data have been processed successfully on a computer system at the United States Geological Survey, no warranty expressed or implied is made regarding the utility of the data on another system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data.
TIFF
0.000
0.000
DVD-ROM
Call USGS for details
Call USGS for Details
20060605
United States Geological Survey
REQUIRED: The person responsible for the metadata information.
mailing and physical address
600 4th Street South
St. Petersburg
Florida
33704
USA
727-803-8747
Call Survey for Details
FGDC Content Standards for Digital Geospatial Metadata
FGDC-STD-001-1998
local time
http://www.esri.com/metadata/esriprof80.html
ESRI Metadata Profile
enhttp://www.esri.com/metadata/esriprof80.htmlESRI Metadata Profile
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.722merge_5.tif298001322001273800027160001-82.997385-82.75738224.7462924.5447431ISO 19115 Geographic Information - MetadataDIS_ESRI1.0dataset002file://\\LIDAR1\C$\LIDAR\DRTO\LIDAR\merge_52\merge_5.tifLocal Area Network0.000Raster DatasetNAD_1983_UTM_Zone_17N2148005Meter1 Meter = 1 Meter(s)44005Meter1 Meter = 1 Meter(s)200606051609300020060605161151002006060516093000FALSE{7F732A71-5EE2-413D-9A23-AA46DCF0A00A}20060605