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OCM Partners, 2023: 2007 USGS/NPS/NASA Experimental Advanced Airborne Research Lidar (EAARL): Northern Gulf of Mexico Barrier Islands,

Item Identification

Title: 2007 USGS/NPS/NASA Experimental Advanced Airborne Research Lidar (EAARL): Northern Gulf of Mexico Barrier Islands
Short Name: usgs2007_northgulf_m522_metadata
Status: Completed
Publication Date: 2009

A bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the northern Gulf of Mexico barrier islands and Naval

Live Oaks was produced from remotely sensed, geographically referenced elevation measurements cooperatively by the U.S. Geological

Survey (USGS), the National Park Service (NPS), and the National Aeronautics and Space Administration (NASA). This data set provides the

those bare earth elevation measurements of the barrier islands in the following counties:

St. Bernard in LA, Harrison and Jackson in MS, Mobile and Baldwin in AL, and Escambia and Santa Rosa in FL.

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 kilohertz or higher 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 subsequent elevation maps for an area are analyzed, they provide

managers with a useful tool to make management decisions regarding land development.

Original contact information:

Contact Name: Amar Nayegandhi or John Brock at USGS

Contact Org: Jacobs Technology, contracted to USGS

Title: Computer Scientist

Phone: 727-803-8747 x3026



The purpose of this project was to produce a highly detailed and accurate bare earth digital elevation map of the northern Gulf

of Mexico barrier islands for use as a management tool and to make these data available to natural resource managers and research




Supplemental Information:

Unprocessed 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 unprocessed 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 unprocessed waveform Lidar data acquired by the EAARL to georeferenced spot (x, y, z) returns for

"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 are named after the U.S. Geological Survey Alpha

Quarter-Quad naming convention ('QQ_naming_convention.doc'). The development of custom software for creating these data products has

been supported by the U.S. Geological Survey CMG Program's Decision Support for Coastal Parks, Sanctuaries, and Preserves project.

Processed data products are used by the U.S. Geological Survey 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.


Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
None bare earth
None derived surface
None Hurricanes
None resource management

Temporal Keywords

Thesaurus Keyword
None 2007
None June

Physical Location

Organization: Office for Coastal Management
City: Charleston
State/Province: SC

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: None Planned
Data Presentation Form: LAS
Entity Attribute Overview:

The LAS grid is encoded with a 1-meter resolution.

Entity Attribute Detail Citation:

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). Z value

is referenced to orthometric elevations derived from National Geodetic Survey Geoid Model, GEOID03.

Distribution Liability:

Although these data have been processed successfully on a computer system at the U.S. Geological Survey,

no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of

distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the

data described and (or) contained herein. Reference herin to any specific commercial product, process, or service by trade name,

trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United

States Government or any agency thereof.

Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the Office for Coastal Management or

its partners.

Data Set Credit: Acknowledgement of the U.S. Geological Survey, Florida Integrated Science Center, 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 the U.S. Geological Survey staff. These data are not legal documents and are not to be used as such. Although the U.S. Geological Survey is making these datasets available to others who may find the data of value, the U.S. Geological Survey, National Park Service, and National Aeronautical and Space Administration request they be acknowledged as originators of this data in future products or derivative research.

Support Roles

Data Steward

CC ID: 690653
Date Effective From: 2009
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202


CC ID: 690655
Date Effective From: 2009
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202

Metadata Contact

CC ID: 690656
Date Effective From: 2009
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202

Point of Contact

CC ID: 690654
Date Effective From: 2009
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202


Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1138580
W° Bound: -89.20349
E° Bound: -87.083264
N° Bound: 30.389948
S° Bound: 29.762884

Extent Group 1 / Time Frame 1

CC ID: 1138579
Time Frame Type: Range
Start: 2007-06-27
End: 2007-06-30

Spatial Information

Spatial Representation

Representations Used

Vector: Yes

Access Information

Security Class: Unclassified
Security Classification System:


Security Handling Description:


Data Access Procedure:

This data can be obtained on-line at the following URL:;

Data Access Constraints:


Data Use Constraints:

Users should be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no

longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its


Distribution Information

Distribution 1

CC ID: 743052
Download URL:
File Name: Customized Download

Create custom data files by choosing data area, product type, map projection, file format, datum, etc.

Distribution 2

CC ID: 743053
Download URL:
File Name: Bulk Download

Simple download of data files.



CC ID: 743055
URL Type:
Online Resource


CC ID: 743056
URL Type:
Online Resource

Activity Log

Activity Log 1

CC ID: 690698
Activity Date/Time: 2016-05-23

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 690697
Activity Date/Time: 2017-11-14

Converted from FGDC Content Standards for Digital Geospatial Metadata (version FGDC-STD-001-1998) using '' script. Contact Tyler Christensen (NOS) for details.

Activity Log 3

CC ID: 718709
Activity Date/Time: 2018-02-08

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 743054
Activity Date/Time: 2018-03-13

Partial upload to move data access links to Distribution Info.

Technical Environment


Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcMap

Data Quality


The expected accuracy of the measured variables is as follows: attitude within 0.07 degree, 3 cm nominal laser ranging accuracy,

and vertical elevation accuracy of +/-15 cm for the topographic surface. Quality checks are built into the data-processing software.

Horizontal Positional Accuracy:

Unprocessed elevation measurements have been determined to be within 1 meter horizontal accuracy.

Vertical Positional Accuracy:

Elevations of the DEM are vertically consistent with the point elevation data, +/-15 cm.

Completeness Report:

Several regions of the dataset are labeled as "No Data", which corresponds to a cell value of -32767 m in the LAS 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.

Conceptual Consistency:

Each file contains data located in USGS 24K Quarter Quadrangle tile and are named after the USGS Alpha Quarter Quad naming convention.

AAOOOaoq, where AA is the positive whole number component of the latitude. OOO is the positive whole number component of the longitude

(zero-padded to a width of 3); a is an alpha character a-h designating which quad in the degree of latitude; where a is closest to 0 minutes

and h is closest to the next full degree. Each represents 1/8 of a degree; o is a numeral 1-8 designating which quad in the degree of

longitude, where 1 is closest to 0 minutes and 8 is closest to the next full degree. Each represents 1/8 of a degree; q is an alpha

character a-d designating which quarter in the quad, where a is SE, b is NE, c is NW, and d is SW. Each quarter-quad is 1/16 of a degree

in latitude and 1/16 of a degree in longitude.



EAARL Coastal Topography-Northern Gulf of Mexico, 2007: Bare Earth

CC ID: 1138575
Publish Date: 2008-01-01
Extent Type: Range
Extent Start Date/Time: 2007-06-27
Extent End Date/Time: 2007-06-30
Source Contribution:

unknown | Source Geospatial Form: remote-sensing image | Type of Source Media: Point elevation measurements collected by the EAARL sensor.

Process Steps

Process Step 1

CC ID: 1138576

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 (532 nm) 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 U.S. Geological Survey office in St. Petersburg and the NASA office at

Wallops Flight Facility. The navigational data are processed at Wallops Flight Facility. The navigational and unprocessed 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).

Process Date/Time: 2007-01-01 00:00:00

Process Step 2

CC ID: 1138577

The NOAA Office for Coastal Management (OCM) received files in LAS format. The files contained LiDAR intensity and elevation measurements.

OCM performed the following processing on the data to make it available within Digital Coast:

1. The data were converted from UTM, Zone 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.

Process Date/Time: 2009-11-01 00:00:00

Catalog Details

Catalog Item ID: 50105
GUID: gov.noaa.nmfs.inport:50105
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-15 15:24+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2022-08-09 17:11+0000
Metadata Record Published: 2022-03-16
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2022-03-16
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2023-03-16