United States Geological Survey, FISC St. PetersburgDecember 2007EAARL Topography-Padre Island National SeashoreFirstraster digital dataOpen File Report2007-1431The USGS, in cooperation with the National Park Service (NPS) and the National Aeronautics and Space Administration (NASA), provides the coastal management community with usable digital elevation products. The USGS processes aircraft Lidar data (provided by NASA), develops software tools and algorithms to use and analyze the data and make products available to the coastal management community through a variety of media, including the internet, CD-ROMs, DVDs and data reports.St. Petersburg, FLUSGSElevation maps (also known as Digital Elevation Models or DEMs) of Padre Island National Seashore were produced from remotely-sensed, geographically-referenced elevation measurements in cooperation with NASA and NPS. Point data in ascii text files were interpolated in a GIS to create a grid or digital elevation model (DEM) of each beach surface. Elevation measurements were collected in Texas, over Padre Island National Seashore, using the NASA Experimental Advanced Airborne Research Lidar (EAARL), a pulsed laser ranging system mounted onboard an aircraft to measure ground elevation 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 beach at approximately 60 meters per second while surveying from the low-water line to the landward base of the sand dunes. The EAARL, developed by the National Aeronautics and Space Administration (NASA) located 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. The ability to sample large areas rapidly and accurately is especially useful in morphologically dynamic areas such as barrier beaches. Quick assessment of topographic change can be made following storms comparing measurements against baseline data. When subsequent elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding coastal development.One goal of the project is to produce highly detailed and accurate digital elevation maps (DEMs) of National Seashores and coastal parks for use as a management tool and to make these maps available to natural resource managers within the parks.Raw Lidar data is not in a format that is generally usable by National 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 multitiered processing system developed by a USGS/NASA collaborative for the use of topographic Lidar in coastal change assessment. Specialized processing algorithms are used to convert raw waveform Lidar data acquired by the EAARL to georeferenced spot (x,y,z) returns for "first return" and "bare earth" topography. These data are then converted to the NAD83 horizontal and NAVD88 vertical datum (using the Geoid 99 model). The final products are 2x2-km map tiles written out in a standard geotiff format with associated metadata information. These tiles are created for visual interpretation and regional quantitative analysis. Metadata files include the standard FGDC format.en200509302005100120051002ground conditionUnknown466001.000000468001.0000004188000.0000004190000.000000LidarExperimental Advanced Airborne Research Lidardigital elevation modelelevation changelaser altimetryderived surfaceresource managementbare earth elevationALPSAirborne Lidar Processing SystemNONEPadre Island National SeashoreTexasUnited States Gulf of Mexicobare earth topographyAny use of these data signifies a user's agreement to comprehension and compliance of the U. S. Geological Survey Standard Disclaimer. Ensure all portions of metadata are read and clearly understood before using these data in order to protect both user and U. S. Geological Survey interests. See section 6.3 Distribution Liability.Although the U. S. Geological Survey is making these data sets available to others who may find the data of value, U. S. Geological Survey does not warrant, endorse, or recommend the use of thes data for any given purpose. The user assumes the entire risk related to the use of these data. These data sets are not for navigational purposes. U. S. Geological Survey is providing these data "as is", and U. S. Geological Survey 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 U. S. Geological Survey 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, FISC St. Petersburg as a data source would be appreciated in products developed from these data, and such acknowledgement as is standad 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 U. S. Geological Survey 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.United States Geological Survey, FISC St. PetersburgDr. John C. BrockPhysical Oceanographermailing and physical address
600 4th Street South
St. PetersburgFlorida33701-USA727 803-8747 ext3088727 803-2031jbrock@usgs.govMonday-Friday, 8-5, ESTThe U. S. Geological Survey, FISC St. Petersburg, would like to acknowledge NASA Goddard Space Flight Center for their cooperation and assistance in the development of the data. The U. S. Geological Survey would also like to acknowledege National Park Service management and personnel at Padre Island National Seashore.Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.722Brock, J.C.; Wright, C.W.; Sallenger, A.H; Krabill, W.B., and Swift, R.N2003Basis and Methods of NASA Ariborne Topographic Mapper Lidar Surveys for Coastal Studiesjournal articleWest Palm Beach, FLJournal of Coastal ResearchJohn Brock and Asbury Sallenger, US Geological Survey2001Airborne Topographic Lidar Mapping for Coastal Science and Resource ManagementUSGS Open File ReportSt. Petersburg, FLUS Geological SurveyRaster DatasetUnclassifiedThe expected accuracy of the measured variables are as follows: attitude within 0.07 degree, 3-cm nominal ranging accuracy, and verticle elevation accuracy of +/- 15cm (bald earth). Quality checks are built into the data-processing software.unknownRaw elevation measurements have been determined to be within 1.5 meter horizontal accuracy. Processing steps (grid interpolation) may introduce additional error which has not been tested at the time of this publication.Elevations of the DEM are vertically consistent with the point elevation data, +/- 15cm.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 U. S. Geological Survey, FISC St. Petersburg office and the NASA Wallops office. The navigational data are processed at Wallops. 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).2006United States Geological SurveyAmar NayegandhiComputer Scientistmailing and physical address
600 4th Street South
St. PetersburgFlorida33701-USA727-803-87478:00am to 5:00pm Monday thru Friday, ESTCall Survey for Details ALPS (Airborne Lidar Processing System) using Yorick and TCL/TK programsThe 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 (e.g. spikes, large facets) of the lidar processing. Pixels within the AOI polygons were given a raster value of -100 to correspond with the classification of 'No Data'20070802mailing and physical address18001 Old Cutler Road, Suite 419Palmetto BayFL33157USANational Park Service South Florida/Caribbean Network(305) 252-0347ArcCatalog 9.2July 2007mailing and physical address600 4th Street SouthSt. PetersburgFL33701USA727-803-8747US Geological Survey, FISC St. PetersburgLaurinda J. TraversMetadata created from XML files.ArcCatalog 9.2.0 13242007082920050930ground conditionRasterGrid Cell2000200011.0000001.00000032Upper LeftFALSENone1unique valuesTRUEGEOTIFFmetermeter-100DEMrow and column1.0000001.000000metersUniversal Transverse Mercator140.999600-75.0000000.000000500000.0000000.000000North American Datum of 1983Geodetic Reference System 806378137.000000298.257222GCS_North_American_1983NAD_1983_UTM_Zone_14NNorth American Vertical Datum of 1988.15metersExplicit elevation coordinate included with horizontal coordinatesThe attributes measured are as follows: variables measured by EAARL - distance between aircraft and GPS satellites (m), attitude information (roll, pitch, heading in degrees), scan angle (degrees), second of the epoch (sec), 1-ns time-resolved return intensity waveform (digital counts), and co-registered digital aerial photography. For derived variables, WGS84, NAD83 or other UTM eastings and northings (m), NAVD88 elevations (m), and peak amplitude (intensity). For derived surfaces, bare-earth elevations, and first-return elevations.United States Geological Survey, FISC St. Petersburgmailing address
600 4th Street South
St. PetersburgFL33701USA727-803-8747Call Office for Details8:30-5:00 M-F ESTThe 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.15.27515.275Contact USGS for details.Contact USGS for Details20050930200510012005100220080108US Geological Survey, FISC St. PetersburgLaurinda J. Traversmailing and physical address
600 4th Street South
St. PetersburgFlorida33701USA727-803-8747Call Survey for Details8:30-5:00 M-F ESTFGDC Content Standards for Digital Geospatial MetadataFGDC-STD-001-1998local timehttp://www.esri.com/metadata/esriprof80.htmlESRI Metadata Profileen2008010912434800FALSE20050712100814002008010815321600CalculateStatistics D:\ASIS04_geotiffs\ASIS2004 1 1 # D:\ASIS04_geotiffs\ASIS2004 {2FE8960B-4EB5-4CFC-AB5F-BDFF45D64320}Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.0.0.535466001468001419000041880001-75.386493-75.3636737.85689737.8387991ISO 19115 Geographic Information - MetadataDIS_ESRI1.0dataset002file://\\IGSAFPESWS114\D$\Science_Support_PC\L_Travers\J_Brock\Updated_Lidar_OFRS\PAIS\Metadata\Meta_temps\THST_meta_tempLocal Area Network15.275Raster DatasetNAD_1983_UTM_Zone_18N2120001Meter1 Meter = 1 Meter(s)20001Meter1 Meter = 1 Meter(s)20080108