gov.noaa.csc.maps:2008_USGS_Assateauge_m531 Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Coastal Services Center (CSC) U.S. Geological Survey (USGS) National Park Service (NPS) National Aeronautics and Space Administration (NASA) 2009 Charleston, SC NOAA's Ocean Service, Coastal Services Center (CSC) http://www.csc.noaa.gov/lidar http://www.csc.noaa.gov This is a bare earth data set that was collected 24-25 March 2008 along the shoreline of the Assateague Island National Seashore in Maryland and Virginia. The data falls in these counties: Worcester (MD) and Accomack (VA). A footprint of the data coverage may be viewed at: ftp://ftp.csc.noaa.gov/pub/crs/beachmap/kmzs/USGS_Assateague_Island_National_Seashore_Lidar.kmz ASCII xyz point cloud data were produced from remotely sensed, geographically referenced elevation measurements cooperatively by the U.S. Geological Survey (USGS), the National Park Service (NPS), and National Aeronautics and Space Administration (NASA). 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 easily surveyed within a 3- to 4-hour mission. When subsequent elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding land development. The purpose of this project was to produce a highly detailed and accurate bare-earth digital elevation map of the Assateague Island National Seashore in Virginia and Maryland for use as a management tool and to make these data available to natural resource managers and research scientists. Raw lidar data are not in a format that is generally usable by resource managers and scientists for scientific analysis. 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 Program (CMGP) 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 Airborne 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. the zero crossing of the second derivative (that is, detection of local maxima) is used to detect "first surface" topography, while the trailing edge algorithm (that is, the algorithm searches for the location prior to the last return where direction changes along the trailing edge) is used to detect the range to the last return or "bare earth". Statistical filtering, known as the Random Consensus Filter (RCF), is used to remove false bottom returns and other outliers from the EAARL topography data. The filter uses a grid of non-overlapping square cells (buffer) of user-defined size overlaid onto the original point cloud. The user also defines the vertical tolerance (vertical width) based on the topographic complexity and point sampling density of the data. The maximum allowable elevation range within a cell is established by this vertical tolerance. An iterative process searches for the maximum concentration of points within the vertical tolerance, and removes those points outside of the tolerance (Nayegandhi and others, 2009). 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 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. 20080324 20080325 ground condition Complete None planned -75.402363 -75.091363 38.326138 37.851138 ISO 19115 Topic Category elevation None Bathymetry/Topography Airborne Lidar Processing System ALPS Digital Elevation Model DEM EAARL Experimental Advanced Airborne Research Lidar laser altimetry Lidar remote sensing topography None US Assateague Island National Seashore Virginia Maryland Accomack County Worcester County None Bare Earth None 2008 None 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. Amar Nayegandhi Jacobs Technology, U.S. Geological Survey, FISC, St. Petersburg, FL Computer Scientist mailing and physical

600 4th Street South

Saint Petersburg FL 33701 USA 727-803-8747 (x3026) 727-803-2031 anayegandhi@usgs.gov M-F, 8:00-5:00 EST ftp://ftp.csc.noaa.gov/pub/crs/beachmap/kmzs/USGS_Assateague_Island_National_Seashore_Lidar.kmz This kmz file shows the lidar footprint for the 2008 USGS/NPS/NASA EAARL for Assateague Island National Seashore. kmz The U.S. Geological Survey, National Park Service, and National Aeronautics and Space Administration request to be acknowledged as originators of this data in future products or derivative research. Acknowledgment 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. Unclassified Unclassified None Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.2.1350 The expected accuracy of the measured variables is as follows: attitude within 0.07 degree, 3-centimeter nominal ranging accuracy, and vertical elevation accuracy of +/-15 centimeters for the topographic surface. Quality checks are built into the data-processing software. Unknown Several regions of the dataset are labeled as "No Data". 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. Raw elevation measurements have been determined to be within 1 meter in horizontal accuracy. Elevations are vertically consistent with the point elevation data, +/-15 centimeters. 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, Florida 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 Airborne 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). 20080915 Amar Nayegandhi Jacobs Technology, U.S. Geological Survey, FISC, St. Petersburg, FL Computer Scientist mailing and physical

600 4th Street South

Saint Petersburg FL 33701 USA 727-803-8747 (x3026) anayegandhi@usgs.gov M-F, 8:00-5:00 EST Metadata imported into ArcCatalog from XML file. 20080915 Xan Yates Jacobs Technology, U.S. Geological Survey, FISC, St. Petersburg, FL GIS/Image Analyst/Metadata Specialist mailing and physical

600 4th Street South

St. Petersburg FL 33701 USA 727-803-8747 (x3086) M-F, 8:00-5:00 EST The NOAA Coastal Services Center (CSC) received 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, Zone 18 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. 201002 Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Coastal Services Center (CSC) CEM Project Scientist mailing and physical

2234 South Hobson Ave.

Charleston SC 29405 US 843-740-1200 tcm@csc.noaa.gov The NOAA National Geophysical Data Center (NGDC) received Lidar data files by ftp. The data received compressed containing 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 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. 20110427 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 0.0000001 0.0000001 Decimal degrees North American Datum of 1983 Geodetic Reference System 80 6378137.000000 298.257222 Ellipsoid 0.001 Meters Explicit elevation coordinate included with horizontal coordinates The LAS grid is encoded with a 1 meter resolution. The input parameters for the Random Consensus Filter were: grid cell size (buffer) = 6 meters x 6 meters; vertical tolerance (vertical width) = 50 centimeters. The variables measured by EAARL are distance between aircraft and GPS satellites (meters), attitude information (roll, pitch, heading in degrees), scan angle (degrees), second of the epoch (seconds), and 1-nanosecond time-resolved return intensity waveform (digital counts). Z value is referenced to orthometric elevations derived from National Geodetic Survey Geoid Model, GEOID03. Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Coastal Services Center (CSC) CEM Project Scientist mailing and physical

2234 South Hobson Ave.

Charleston South Carolina 29405 USA 843.740.1200 tcm@csc.noaa.gov 9:00am - 5:00pm Downloadable Data 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 herein 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 Coastal Services Center or its partners. This data can be obtained on-line at the following URL: http://www.csc.noaa.gov/lidar 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 Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Coastal Services Center (CSC) CEM Project Scientist mailing and physical

2234 South Hobson Ave.

Charleston South Carolina 29405 USA 843.740.1200 tcm@csc.noaa.gov 9:00am - 5:00pm FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998