gov.noaa.csc.maps:alace_1996 DOC/NOAA/NOS/CSC/CRS > Coastal Remote Sensing Program, Coastal Services Center, National Ocean Service, NOAA, U.S. Department of Commerce 20061016 This data set has been extracted from one much larger.See the URL for the location of this larger data set. http://www.csc.noaa.gov/lidar 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. File names reference approximate date of collection. This data was collected as part of an effort to map beach topography efficiently and cheaply. 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 file names include collection date. 1996 2002 Ground condition Complete None planned -66.0 -160.0 50.0 24.0 GCMD EARTH SCIENCE > LAND SURFACE > Topography > Terrain Elevation None lidar laser beach topography digital elevation model DEM erosion None U.S. Coastline None 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. 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. Coastal Remote Sensing Program TCM Project Scientist mailing and physical address

2234 South Hobson Avenue

Charleston South Carolina 29405 United States (843) 740-1200 csc@csc.noaa.gov Airborne Topographic Mapper LIDAR data were collected in partnership with the National Oceanic and Atmospheric Administration (NOAA) Coastal Services Center, the NASA Wallops Flight Facility, the U. S. Geological Survey (USGS) Center for Coastal and Regional Marine Geology, and the NOAA Aircraft Operations Center. 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. Not applicable. 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'. The ATM LIDAR elevation points are known to be horizontally accurate to +/- 0.8 meters at an aircraft altitude of 700 meters. 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. 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. Unknown The NOAA National Geophysical Data Center (NGDC) received Lidar data files on external harddrive. The disk contains LiDAR data from the NOAA Coastal Services Center. The data are currently being served via Digital Coastl at http://www.csc.noaa.gov/digitalcoast/. The data can be used to re-populate the system. The data are provided on this disk in LAS format. LAS format is an industry standard for serving LiDAR data. The data are exclusively in geographic coordinates, however, the datums used vary. Most are NAD 83, however some are in ITRF. Vertical systems include both ellipsoid (ITRF and NAD 83) and NAVD 88. For NAVD 88 values, Geiod 03 is primarily used; however, data received in NAVD 88 prior to 2003 was processed using Geoid 99. 20060103 DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce Pamela Grothe Mailing and Physical Address

NOAA/NESDIS/NGDC E/GC1 325 Broadway

Boulder CO 80305-3328 USA (303) 497-6120 (303) 497-6958 (303) 497-6513 pamela.grothe@noaa.gov 7:30-5:00 Mountain Contact Data Center Point 8.53486352905309e-10 7.68624987507489e-10 Decimal degrees International Terrestrial Reference Frame of 1994 Geodetic Reference System 80 6378137 298.257 ITRF94 Ellipsoid 0.01 meters Explicit elevation coordinate included with horizontal coordinates NOAA Coastal Services Center Coastal Remote Sensing Program Manager mailing and physical address

2234 South Hobson Avenue

Charleston SC 29405-2413 none csc@csc.noaa.gov 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. This data can be obtained on-line at the following URL: http://csc-s-maps-q.csc.noaa.gov/dataviewer/viewer.html. DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce Pamela Grothe Mailing and Physical Address

NOAA/NESDIS/NGDC E/GC1 325 Broadway

Boulder CO 80305-3328 USA (303) 497-6120 (303) 497-6958 (303) 497-6513 pamela.grothe@noaa.gov 7:30-5:00 Mountain Contact Data Center Disclaimer While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty. The National Geophysical Data Center serves as the archive for this LIDAR data. NGDC should only be contacted for this data if it cannot be obtained from NOAA Coastal Services Center. 20111119 20111119 20121119 NOAA Coastal Services Center Keil Schmid Metadata Specialist mailing and physical address

2234 South Hobson Avenue

Charleston SC 29405-2413 none metadata@csc.noaa.gov FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998