Short Citation:
Office for Coastal Management, 2021: 1998 Fall Gulf Coast NOAA/USGS/NASA Airborne LiDAR Assessment of Coastal Erosion (ALACE) Project for the US Coastline, https://www.fisheries.noaa.gov/inport/item/48152.

Item Identification

Title: 1998 Fall Gulf Coast NOAA/USGS/NASA Airborne LiDAR Assessment of Coastal Erosion (ALACE) Project for the US Coastline
Short Name: atm1998_fall_gulf_coast_m22_metadata
Status: Completed
Publication Date: 2000-01-01
Abstract:

This data set includes data collected during Fall 1998 and covers coastlines of the states of Louisiana, Mississippi,

Alabama, and Florida.

Laser beach mapping uses a pulsed laser ranging system mounted onboard an aircraft to measure ground

elevation and coastal topography. The laser emits laser beams at high frequency and is directed downward at the

earth's surface through a port 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 aircraft travels over the beach at approximately 60 meters per second while surveying from

the low water line to the landward base of the sand dunes.

Original contact information:

Contact Org: NOAA Office for Coastal Management

Phone: 843-740-1202

Email: coastal.info@noaa.gov

Purpose:

This data was collected as part of an effort to map beach topography and assess beach change along the US coastline.

Notes:

10175

Supplemental Information:

This data set was collected with a LIDAR (LIght Detection And Ranging) instrument designed and developed by the Observational

Sciences Branch (OSB) of NASA at the Wallops Flight Facility in Virginia. The instrument, originally designed for mapping ice sheets

in Greenland, is called the Airborne Topographic Mapper or ATM. The ATM II (the latest version), operates with a Spectra Physics

laser transmitter, which provides a 7 nanoseconds long, 250 microjoules pulse at a frequency-doubled wavelength of 523 nanometers

in the blue-green spectral region. The laser transmitter can function at pulse rates from 2 to 10 kilohertz (kHz). The laser system

with a separate cooling unit weighs approximately 45 kilograms (kg) and requires approximately 15 amperes of power at 115 volts.

The transmitted laser pulse is reflected to the surface of the earth with the aid of a small folding mirror mounted on the back of a

secondary mirror of a rotating scan mirror assembly mounted directly in front of the telescope. The scan mirror, which is rotated at 20

hertz, is comprised of a section of round aluminum stock, machined to a specific off-nadir angle. A scan mirror with the off-nadir

angle of 15 degrees was utilized, producing an elliptical scan pattern with a swath width equal to 50 percent of the approximately

700-meter aircraft altitude. The reflected laser pulse is transmitted to a photo-multiplier assembly that consists of a lens, a

narrow bandpass filter, and a single photomultiplier tube.

Note: The Spatial Reference section of this document may lack fully FGDC-compliant information regarding projection parameters

(i.e., Central meridian, false Northing, etc.). The State Plane or UTM Zone will be supplied, and the corresponding parameters can be

found in Appendix C of: Snyder, John, 1987, Map Projections, a Working Manual (U.S. Geological Survey Professional Paper 1395):

Washington, U.S. Government Printing Office.

Keywords

Theme Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Science Keywords Earth Science > Land Surface > Topography > Terrain Elevation > Topographical Relief Maps
Global Change Master Directory (GCMD) Science Keywords Earth Science > Oceans > Bathymetry/Seafloor Topography > Seafloor Topography
Global Change Master Directory (GCMD) Science Keywords Earth Science > Oceans > Coastal Processes > Coastal Elevation
ISO 19115 Topic Category elevation
None beach
None DEM
None digital elevation model
None erosion
None laser
None lidar
None Topography

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords Continent > North America > United States Of America > Alabama
Global Change Master Directory (GCMD) Location Keywords Continent > North America > United States Of America > Florida
Global Change Master Directory (GCMD) Location Keywords Continent > North America > United States Of America > Lousiana
Global Change Master Directory (GCMD) Location Keywords Continent > North America > United States Of America > Mississippi
None Alabama
None Florida
None Louisiana
None Mississippi
None U.S. Coastline

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
Distribution Liability:

This data was collected for the purposes of research. Any conclusions drawn from analysis of this information are not the responsibility

of NOAA, the Office for Coastal Management, or its partners.

Data Set Credit: Airborne Topographic Mapper LIDAR data were collected in partnership with the National Oceanic and Atmospheric Administration (NOAA) Office for Coastal Management, the NASA Wallops Flight Facility, the U. S. Geological Survey (USGS) Center for Coastal and Regional Marine Geology, and the NOAA Aircraft Operations Center.

Support Roles

Data Steward

CC ID: 622646
Date Effective From: 2000-01-01
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Distributor

CC ID: 622648
Date Effective From: 2000-01-01
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Metadata Contact

CC ID: 622649
Date Effective From: 2000-01-01
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Point of Contact

CC ID: 622647
Date Effective From: 2000-01-01
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Extents

Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 622652
W° Bound: -90.967803
E° Bound: -81.872129
N° Bound: 30.400007
S° Bound: 26.384175

Extent Group 1 / Time Frame 1

CC ID: 622651
Time Frame Type: Range
Start: 1998-10-29
End: 1998-11-09

Spatial Information

Spatial Representation

Representations Used

Vector: Yes

Access Information

Security Class: Unclassified
Data Access Procedure:

This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer. The data set is dynamically generated based on

user-specified parameters.

;

Data Access Constraints:

None

Data Use Constraints:

This data was collected for the purposes of research. Any conclusions drawn from analysis of this information

are not the responsibility of NOAA or the Office for Coastal Management. This data is likely to contain returns

from the water surface and vegetation. No processing has been done to remove returns from water or vegetation.

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 limitations.

Distribution Information

Distribution 1

CC ID: 743663
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=22
Distributor:
File Name: Customized Download
Description:

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

Distribution 2

CC ID: 743664
Download URL: https://coast.noaa.gov/htdata/lidar1_z/geoid12a/data/22
Distributor:
File Name: Bulk Download
Description:

Simple download of data files.

URLs

URL 1

CC ID: 743666
URL: https://coast.noaa.gov/dataviewer
URL Type:
Online Resource

URL 2

CC ID: 743667
URL: https://coast.noaa.gov
URL Type:
Online Resource

Activity Log

Activity Log 1

CC ID: 622674
Activity Date/Time: 2016-05-23
Description:

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 622673
Activity Date/Time: 2017-11-14
Description:

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

Activity Log 3

CC ID: 717607
Activity Date/Time: 2018-02-08
Description:

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 743665
Activity Date/Time: 2018-03-13
Description:

Partial upload to move data access links to Distribution Info.

Data Quality

Accuracy:

Raw elevation measurements have been determined to be vertically accurate to within 15 cm. Processing steps (datum conversion,

projection, grid interpolation, etc.) introduce additional error factors which have not been tested at the time of this publication.

Horizontal Positional Accuracy:

The ATM LIDAR elevation points are known to be horizontally accurate to +/- 0.8 meters at an aircraft altitude of 700 meters.

Vertical Positional Accuracy:

The ATM LIDAR elevation measurements have been found to be within +/- 15 centimeters of each other in successive and overlapping

passes of the same area. In comparisons of LIDAR data for a small geographic region with various ground surveys the differences

are between +/- 15 to 20 centimeters. The accuracy of the majority of the data is estimated to be consistent with the above

stated results. At this time, there has been no large scale verification of the data.

Completeness Report:

All elevation data points that appeared to be within a reasonable vertical range were retained, and other points were thrown away.

This filtering process was performed 'by eye'.

Conceptual Consistency:

Not applicable

Lineage

Process Steps

Process Step 1

CC ID: 622639
Description:

The vertical values in this data set have been filtered through visual inspection to find abnormally high and abnormally low values.

In addition, this data was processed using a spatial filtering program that identifies and discards outlier elevation measurements.

This program reads each elevation measurement within a file and identifies "spatially close" points (i.e. those neighboring points

within a fixed radius of the point). The mean and standard deviation is calculated using the elevations of these points. If the

elevation difference from the mean of the point under consideration is more than 2 standard deviations and greater than a defined

distance the point is discarded.

Catalog Details

Catalog Item ID: 48152
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-14 14:19+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2019-07-02 15:17+0000
Metadata Record Published: 2018-03-13
Owner Org: OCM
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Next Review Date: 2019-03-14