2004 USGS/NASA Experimental Advanced Airborne Research Lidar (EAARL): Northern Gulf of Mexico, Post-Hurricane Ivan
This kmz file shows the extent of coverage for the 2004 USGS Northern Gulf Post-Hurricane Ivan lidar data set.
ASCII xyz point cloud data were produced from remotely-sensed, geographically-referenced elevation measurements in cooperation with the U.S. Geological Survey (USGS) and National Air and Space Administration (NASA). Elevation measurements were collected over the area using the NASA Experimental Advanced Airborne Research Lidar (EAARL), 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 beam and the reception of the reflected laser signal in the aircraft. The plane travels over the target area at approximately 50 meters per second at an elevation of approximately 300 meters. The EAARL, developed by NASA at Wallops Flight Facility in Virginia, measures ground elevation with a vertical resolution of 15 centimeters. A sampling rate of 3 kHz or higher results in an extremely dense spatial elevation data set. Over 100 kilometers of coastline can be easily surveyed within a 3 to 4 hour mission time period. When subsequent elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding land development.
|Distributor||DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National
Oceanic and Atmospheric Administration, U.S. Department of Commerce
|Dataset Point of Contact||Wayne Wright
DOI/USGS/CMGP/SPCMSC > St. Petersburg Coastal and Marine Science Center, Coastal and Marine Geology Program, United States Geological Survey, U.S. Department of the Interior
Documentation links not available.
|Data Presentation Form:||
|Dataset Progress Status||Complete|
|Data Update Frequency:||As needed|
Raw lidar data is not in a format that is generally usable by resource managers and scientists. Converting dense Lidar elevation data into a readily usable format without loss of essential information requires specialized processing. The U. S. Geological Survey's Coastal and Marine Geology (CMG) Program 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 Advanced Lidar Processing System (ALPS), a multi-tiered processing system developed by a USGS/NASA collaborative project. Specialized processing algorithms are used to convert raw waveform Lidar data acquired by the EAARL to georeferenced spot (x,y,z) returns for "first surface" and "bare earth" topography. These data are then converted to the North American Datum of 1983 and the North American Vertical Datum of 1988 (using the Geoid 03 model). The files are in the Quarter Quad tiling format and the exact tile location is contained in the filename at n88_########_mf_be where ####### is the Quarter Quad tile ID. The development of custom software for creating these data products has been supported by the USGS CMG Program's 'Decision Support for Coastal Parks, Sanctuaries, and Preserves' project. Processed data products are used by the USGS CMG Program's 'National Assessments of Coastal Change Hazards Project' to quantify the vulnerability of shorelines to coastal change hazards such as severe storms, sea-level rise, and shoreline erosion and retreat. LAS 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 1ns time-resolved return intensity waveform (digital counts). Z value is referenced to orthometric elevations derived from National Geodetic Survey Geoid Model, Geoid03.
|Purpose:||The ASCII elevation data can be used to create raster Digital Elevation Models (DEMs). The purpose of this project is to produce highly detailed and accurate digital elevation maps of the post Hurricane Ivan data for use as a management tool and to make this data available to natural resource managers and research scientists.|
|Time Period:||Unknown to Unknown|
|Spatial Reference System:||urn:ogc:def:crs:EPSG::4269 Ellipsoid in Meters|
|Spatial Bounding Box Coordinates:||
|Spatial Coverage Map:|
|Use Constraints||No constraint information available|
|Fees||Fee information not available.|
Last Modified: 2013-01-22
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