2001 USGS/NASA Airborne Topographic Mapper (ATM) Lidar: Coastal Alabama, Florida,
Louisiana, Mississippi, Texas
This is a non-bare earth data set. ASCII xyz point cloud data were produced from remotely
sensed, geographically referenced elevation measurements cooperatively by the U.S.
Geological Survey (USGS) and National Aeronautics and Space Administration (NASA)
along the coasts of Alabama, Florida (Panhandle), Louisiana, Mississippi and Texas
in 2001. Dates of collection are: 1. Alabama 20011002-20011004, 20011007-20011010
2. Florida 20011002 3. Louisiana 20010909-20010910 4. Mississippi 20010909-20010910
5. Texas 20011012-20011013 Elevation measurements were collected over the area using
the NASA Airborne Topographic Mapper (ATM), a scanning Lidar system that measures
high-resolution topography of the land surface. The ATM system is deployed on a Twin-Otter
or P-3 Orion aircraft and incorporates a green-wavelength laser operating at pulse
rates of 2 to 10 kilohertz. Measurements from the laser ranging device are coupled
with data acquired from internal navigation system (INS) attitude sensors and differentially-corrected
global positioning system (GPS) receivers to measure topography of the surface at
accuracies of 10 to 20 centimeters.
Cite this dataset when used as a source.
|Search and Download
|| Distributor information not available
| Point of Contact
Documentation links not available.
- National Aeronautics and Space Administration (NASA)
|Data Presentation Form:
|| Digital image
|Dataset Progress Status
|Data Update Frequency:
|| Not planned
||Raw Lidar data are 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 GEOID03 model).
The files are in the Quarter-Quad tiling format and the exact tile location is contained
in the filename at ########_fs, 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.
||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 elevation maps
of the Alabama, Florida (Panhandle), Louisiana, Mississippi, and Texas coastlines
for natural resource managers and research scientists.
||2001-09-09 to 2001-10-13
|Spatial Reference System:
|Spatial Bounding Box Coordinates:
|Spatial Coverage Map:
- Airborne Lidar Processing System
- Digital Elevation Model
- Airborne Topographic Mapper
- laser altimetry
- remote sensing
- Northern Gulf of Mexico
| Use Constraints
|| No constraint information available
|| Fee information not available.
|| Lineage statement not available.
- Jacobs Technology, U.S. Geological Survey, FISC, St. Petersburg, FL
- DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department
| Processing Steps
- The data are collected using a twin-otter aircraft. The NASA Airborne Topographic
Mapper (ATM) laser scanner collects the data using a green raster scanning laser.
The data are stored on hard drives and archived at the U.S. Geological Survey, FISC
office in St. Petersburg, FL, and the NASA office at Wallops Flight Facility in Virginia.
The navigational data are processed at Wallops Flight Facility. The navigational and
raw data are then downloaded into the Advanced 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).
- The NOAA Coastal Services Center (CSC) received the files in LAS format. The files
contained LiDAR intensity and elevation measurements. CSC performed the following
processing on the data to make it available within Digital Coast: 1. The data were
converted from UTM Zones 14, 15, 16 coordinates to geographic coordinates. 2. The
data were converted from NAVD88 heights to ellipsoid heights using Geoid03. 3. The
LAS header fields were sorted by latitude and updated.
- The NOAA National Geophysical Data Center (NGDC) received lidar data files via ftp
transfer from the NOAA Coastal Services Center. The data are
currently being served via NOAA CSC Digital Coast at http://www.csc.noaa.gov/digitalcoast/.
The data can be used to re-populate the system. The data are archived in LAS
or LAZ format. The LAS format is an industry standard for LiDAR data developed by
the American Society of Photogrammetry and Remote Sensing (ASPRS); LAZ is a loseless
compressed version of LAS developed by Martin Isenburg (http://www.laszip.org/). The
data are exclusively in geographic coordinates (either NAD83 or ITRF94). The data
are referenced vertically to the ellipsoid (either GRS80 or ITRF94), allowing for
the ability to apply the most up to date geoid model when transforming to orthometric
Metadata Last Modified: 2013-05-07
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