Aircraft Laser/GPS Mapping of Coastal Topography.

Metadata:

• Identification_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: Coastal Remote Sensing/Coastal Services Center

Publication_Date: 19990810

Title: Aircraft Laser/GPS Mapping of Coastal Topography.

Edition: 1999

Other_Citation_Details:

This data set has been extracted from one much larger. See the URL for the location of this larger data set.

Online_Linkage: <http://www.csc.noaa.gov/crs/beachmap/index.html>

Description:

Abstract:

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.

Purpose:

This data was collected as part of an effort to map beach topography efficiently and cheaply.

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 earth's surface 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.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 19980424

Ending_Date: 19980428

Currentness_Reference: 19980424 to 19980428

Status:

Progress: Complete

Maintenance_and_Update_Frequency: None planned

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -124.075

East_Bounding_Coordinate: -124.065

North_Bounding_Coordinate: 44.612765

South_Bounding_Coordinate: 44.590746

Keywords:

Theme:

Theme_Keyword_Thesaurus: GCMD

Theme_Keyword: EARTH SCIENCE > LAND SURFACE > Topography > Terrain Elevation

Theme:

Theme_Keyword_Thesaurus: None

Theme_Keyword: lidar

Theme_Keyword: laser

Theme_Keyword: beach

Theme_Keyword: topography

Theme_Keyword: digital elevation model

Theme_Keyword: DEM

Theme_Keyword: erosion

Place:

Place_Keyword_Thesaurus: None

Place_Keyword: U.S. Coastline

Access_Constraints:

This data set was compiled dynamically, and will exist on ftp.csc.noaa.gov/pub/crs/beachmap until 10 days after 8-10-99 , as /csc/nac2/ftp/pub/crs/beachmap/data/8057mhearne.zip . After 10 days this file will be deleted from the system.

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 Coastal Services Center.

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Coastal Remote Sensing Program

Contact_Position: BeachMap Project Scientist

Contact_Address:

Address_Type: mailing and physical address

Address: 2234 South Hobson Avenue

City: Charleston

State_or_Province: South Carolina

Postal_Code: 29405

Country: United States

Contact_Voice_Telephone: (843) 740-1200

Contact_Electronic_Mail_Address: csc@csc.noaa.gov

Data_Set_Credit:

This data was collected by the Observational Sciences Branch at the NASA Wallops Flight Facility. Portions of the work were funded by the USGS Center for Coastal and Regional Marine Geology, and by the NOAA Coastal Services Center.

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster

Raster_Object_Information:

Raster_Object_Type: Grid cell

Row_Count: 1581

Column_Count: 592

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Grid_Coordinate_System:

Grid_Coordinate_System_Name: State Plane Coordinate System 1983

State_Plane_Coordinate_System:

SPCS_Zone_Identifier: Oregon, South

Lambert_Conformal_Conic:

Standard_Parallel: 42.333333

Standard_Parallel: 44.000000

Longitude_of_Central_Meridian: -120.500000

Latitude_of_Projection_Origin: 41.666667

False_Easting: 4921249.999500

False_Northing: 0.000000

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: coordinate pair

Coordinate_Representation:

Abscissa_Resolution: 0.259672760101472

Ordinate_Resolution: 0.3647066112

Planar_Distance_Units: survey feet

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983

Ellipsoid_Name: Geodetic Reference System 80

Semi-major_Axis: 6378137

Denominator_of_Flattening_Ratio: 298.257

Vertical_Coordinate_System_Definition:

Altitude_System_Definition:

Altitude_Datum_Name: National Geodetic Vertical Datum of 1929

Altitude_Resolution: 0.0328

Altitude_Distance_Units: feet

Altitude_Encoding_Method:

Explicit elevation coordinate included with horizontal coordinates

Metadata_Reference_Information:

Metadata_Date: 19980331

Metadata_Review_Date: 19980331

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: NOAA Coastal Services Center

Contact_Position: Metadata Specialist

Contact_Address:

Address_Type: mailing and physical address

Address: 2234 South Hobson Avenue

City: Charleston

State_or_Province: SC

Postal_Code: 29405-2413

Contact_Voice_Telephone: none

Contact_Electronic_Mail_Address: metadata@csc.noaa.gov

Metadata_Standard_Name:

FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998