USGS, FISC St. Petersburg, FL Spring 2007 first remote-sensing image Open File Report 2007-1007 FISC St. Peterburg USGS \\ fr_e666_n4506edit.tif A first return elevation map (also known as a Digital Elevation Model or DEM) of Fire Island National Seashore was produced from remotely-sensed, geographically-referenced elevation measurements in cooperation with the U.S. Geological Survey (USGS), National Air and Space Administration (NASA), and the National Park Service (NPS). 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 m. 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 kHz or higher results in an extremely dense spatial elevation data set. Over 100 kilometers of coastline can be easily surveyed within a 3- to 4-hour mission time period. 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 first return digital elevation map of Fire Island National Seashore for use as a management tool and to make this map available to natural resource managers. Raw lidar data is not in a format that is generally usable by Park Service 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 USGS converts raw lidar data into a GIS-compatible map product to be provided to National Park Service 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 "bald 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). Each file contains data located in a 2 km by 2 km tile where the upper left bound can be quickly assessed through the file name. The first number in the filename (e######) is the left most UTM easting coordinate in meters, the second number (n#######) is the top most UTM northing coordinate in meters, and the third number (##) is the UTM zone the tile is located. en 20050425 ground condition Complete None planned -72.772889 -72.748594 40.773496 40.755024 666001.000000668002.0000004504000.0000004506001.000000 LIDAR Experimental Advanced Airborne Research Lidar EAARL Digital Elevation Model elevation change laser altimetry derived surface resource management first return elevation ALPS Airborne Lidar Processing System REQUIRED: Reference to a formally registered thesaurus or a similar authoritative source of theme keywords. Fire Island New York Any use of these data signifies a user's agreement to comprehension and compliance of the USGS Standard Disclaimer. Ensure all portions of metadata are read and clearly understood before using these data in order to protect both user and USGS interests. See section 6.3 Distribution Liability. Although the USGS is making these data sets available to others who may find the data of value, USGS does not warrant, endorse, or recommend the use of this data for any given purpose. The user assumes the entire risk related to the use of these data. Dr. John C Brock United States Geological Survey, Center for Coastal and Watershed Studies Physical Oceanographer mailing and physical address

600 4th Street South

Saint Petersburg FL 33701 USA 727 803-8747 ext3088 727 803-2031 jbrock@usgs.gov Monday-Friday, 8-5, EST USGS is providing these data "as is", and USGS disclaims any and all warranties, whether expressed or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose. In no event will USGS be liable to you or to any third party for any direct, indirect, incidental, consequential, special, or exemplary damages or lost profits resulting from any use or misuse of these data. Acknowledgement of the U.S. Geological Survey Center for Coastal and Watershed Studies 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 USGS staff. Users should be aware that comparisons with other data sets for the same area from other time periods may be inaccurate due to inconsistencies resulting from changes in photo interpretation, mapping conventions, and digital processes over time. These data are not legal documents and are not to be used as such. Unclassified Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.1.1332 Raster Dataset The expected accuracy of the measured variables are as follows: attitude within 0.07 degree, 3-cm nominal ranging accuracy, and vertical elevation accuracy of +/-15 cm for the topographic surface. Quality checks are built into the data-processing software. Several regions of the dataset are labeled as "No Data", which corresponds to a cell value of -100 m in the GeoTiff 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. Raw elevation measurements have been determined to be within 1 meter horizontal accuracy. Elevations of the DEM are vertically consistent with the point elevation data, +/-15 cm. 20050424 ground condition 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 (532nm) 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 USGS office in St. Petersburg and the NASA office at Wallops Flight Facility. 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). June 2005 - February 2006 Amar Nayegandhi ETI Professionals, Inc. Contracted with US Geological Survey Computer Scientist mailing and physical address

600 4th Street South

St. Petersburg Florida 33701 USA 727-803-8747 8:00am to 5:00pm Monday thru Friday, EST Call Survey for Details The raster dataset was opened in ERDAS IMAGINE for editing. An Area of Interest (AOI) polygon was drawn around regions of poor data quality. Poor data quality was determined visually by locating gaps in the data as well as artifacts of the lidar processing. Pixels within the AOI polygons were given a raster value of -100 to correspond with other areas of No Data. July 2006 Judd Patterson National Park Service South Florida / Caribbean Network Inventory and Monitoring Program Research Assistant mailing and physical address

18001 Old Cutler Rd

Suite 419

Miami Florida 33157 USA (305) 252-0347 (305) 253-0463 Metadata imported. \\ 20070807 USGS mailing and physical address

600 4th Street South

St. Petersburg FL 33701 USA 727-803-8747 Metadata imported.D:\Science_Support_PC\L_Travers\J_Brock\Updated_Lidar_OFRS\FIIS\Meta_temps\FIIS_meta_temp.xml2007080711342000 Tiling Index Raster Pixel 2001 2001 1 1.0000001.00000032Upper LeftFALSENone1pixel RGBTRUE row and column 1.000000 1.000000 meters Universal Transverse Mercator180.999600-75.0000000.000000500000.0000000.000000 North American Datum of 1983 Geodetic Reference System 80 6378137.000000 298.257222 GCS_North_American_1983NAD_1983_UTM_Zone_18N North American Vertical Datum of 1988 15 cm meters Explicit elevation coordinate included with horizontal coordinates 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. Jerry Butcher USGS Center for Coastal and Watershed Studies Windows System Administrator mailing address

600 4th Street South

Saint Petersburg FL 33701 USA 727-803-8747 x3049 Lidar DEM (Fire Island) The United States Geological Survey shall not be held liable for improper or incorrect use of the data described and/or contained herein. These data and related graphics are not legal documents and are not intended to be used as such. The information contained in these data is dynamic and may change over time. The data are not better than the original sources from which they were derived. It is the responsibility of the data user to use the data appropriately and consistent within the limitations of geospatial data in general and these data in particular. The related graphics are intended to aid the data user in acquiring relevant data; it is not appropriate to use the related graphics as data. The United States Geological Survey gives no warranty, expressed or implied, as to the accuracy, reliability, or completeness of these data. It is strongly recommended that these data are directly acquired from an USGS server and not indirectly through other sources which may have changed the data in some way. Although these data have been processed successfully on a computer system at the United States Geological Survey, no warranty expressed or implied is made regarding the utility of the data on another system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data. GeoTIFF 0.000 0.000 Call USGS for Details 20050425 20070807 USGS Center for Coastal and Watershed Studies Jeremy Bracone 600 4th Street South Saint Petersburg FL 33701 (727)803-8747 FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 local time enhttp://www.esri.com/metadata/esriprof80.htmlESRI Metadata Profile 2007080711342000{6BB55BE8-80C1-4CDD-9EFA-016DC865BD84}2007080711342000FALSE200708071134200020070807Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.1.1332fr_e666_n4506edit.tif666001668002450600145040001-73.036-73.01180440.688240.6697791ISO 19115 Geographic Information - MetadataDIS_ESRI1.0datasetfile://\\IGSAFPESWS114\D$\Science_Support_PC\L_Travers\J_Brock\Updated_Lidar_OFRS\FIIS\LIDAR\e666_n4506\fr_e666_n4506edit.tifLocal Area Network0020.000Raster DatasetNAD_1983_UTM_Zone_18N2120011Meter1 Meter = 1 Meter(s)20011Meter1 Meter = 1 Meter(s)