gov.noaa.nmfs.inport:48140 eng UTF8 dataset Office for Coastal Management resourceProvider NOAA Office for Coastal Management (843) 740-1202 2234 South Hobson Ave Charleston SC 29405-2413 coastal.info@noaa.gov https://coast.noaa.gov WWW:LINK-1.0-http--link NOAA Office for Coastal Management Website NOAA Office for Coastal Management Home Page information pointOfContact 2026-04-30T00:00:00 ISO 19115-2 Geographic Information - Metadata Part 2 Extensions for imagery and gridded data ISO 19115-2:2009(E) EAARL-B Submerged Topography - Saint Croix and Saint Thomas, U.S. Virgin Islands, 2014 2014_EAARLB_StCroix_StThomas_m4940_metadata 2015-07-25 publication NOAA/NMFS/EDM 48140 https://www.fisheries.noaa.gov/inport/item/48140 WWW:LINK-1.0-http--link Full Metadata Record View the complete metadata record on InPort for more information about this dataset. information https://coast.noaa.gov/dataviewer WWW:LINK-1.0-http--link Data Access Viewer Custom download tool download mapDigital Binary point-cloud data for part of the submerged environs of Saint Croix and Saint Thomas, U.S. Virgin Islands, were produced from remotely sensed, geographically referenced elevation measurements by the U.S. Geological Survey in collaboration with the National Oceanic and Atmospheric Administration's Coral Reef Conservation Program. Elevation measurements were collected over the area using the second-generation Experimental Advanced Airborne Research Lidar, 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 55 meters per second at an elevation of approximately 300 meters, resulting in a laser swath of approximately 240 meters with an average point spacing of 0.5-1.6 meters. The nominal vertical elevation accuracy expressed as the root mean square error (RMSE) is 13.5 centimeters on Saint Croix. Data were insufficient to calculate the nominal vertical elevation accuracy expressed as the root mean square error (RMSE) on Saint Thomas. A peak sampling rate of 15-30 kilohertz results in an extremely dense spatial elevation dataset. More than 100 kilometers of coastline can be surveyed easily within a 3- to 4-hour mission. When resultant elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding land development. Original contact information: Contact Name: Xan Fredericks Contact Org: Cherokee Nation Technology Solutions, U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL Title: Lidar Validation and Processing Analyst Phone: 727 502-8086 Email: afredericks@usgs.gov The purpose of this project was to produce highly detailed and accurate seamless digital elevation maps for part of the submerged environs of Saint Croix and Saint Thomas, U.S. Virgin Islands, for use as a management tool and to make these data available to natural-resource managers and research scientists. Acknowledgment of the U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, as a data source would be appreciated in products developed from these data, and such acknowledgment as is standard for citation and legal practices for data source is expected. Sharing of new data layers developed directly from these data would also be appreciated by the U.S. Geological Survey staff. Users should be aware that comparisons with other datasets for the same area from other periods may be inaccurate because of inconsistencies resulting from changes in photointerpretation, mapping conventions, and digital processes over time. These data are not legal documents and are not to be used as such. completed NOAA Office for Coastal Management (843) 740-1202 2234 South Hobson Ave Charleston SC 29405-2413 coastal.info@noaa.gov https://coast.noaa.gov WWW:LINK-1.0-http--link NOAA Office for Coastal Management Website NOAA Office for Coastal Management Home Page information pointOfContact NOAA Office for Coastal Management (843) 740-1202 2234 South Hobson Ave Charleston SC 29405-2413 coastal.info@noaa.gov https://coast.noaa.gov WWW:LINK-1.0-http--link NOAA Office for Coastal Management Website NOAA Office for Coastal Management Home Page information custodian notPlanned https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4940/supplemental/usvi2014_eaarlb_m4940.kmz Browse graphic kmz EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION > TOPOGRAPHICAL RELIEF MAPS EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > SEAFLOOR TOPOGRAPHY EARTH SCIENCE > OCEANS > COASTAL PROCESSES > COASTAL ELEVATION theme Global Change Master Directory (GCMD) Science Keywords 23.3 OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > CARIBBEAN SEA > VIRGIN ISLANDS place Global Change Master Directory (GCMD) Location Keywords 23.3 LIDAR > Light Detection and Ranging instrument Global Change Master Directory (GCMD) Instrument Keywords 23.3 Geographic Information > LiDAR theme CoRIS Discovery Thesaurus EARTH SCIENCE > Land Surface > Topography> Terrain Elevation EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Bathymetry theme CoRIS Theme Thesaurus ALPS Airborne Lidar Processing System Cessna 310 DEM Digital Elevation Model EAARL-B Experimental Advanced Airborne Research Lidar laser altimetry lidar remote sensing topography 2014 Submerged theme General DOI/USGS/CMG > COASTAL AND MARINE GEOLOGY OCEAN > BATHYMETRY/SEAFLOOR TOPOGRAPHY > SEAFLOOR TOPOGRAPHY OCEAN > COASTAL PROCESSES > COASTAL ELEVATION U.S. DEPARTMENT OF INTERIOR U.S. GEOLOGICAL SURVEY theme Global Change Master Science Directory COUNTRY/TERRITORY > United States of America > U. S. Virgin Islands > U. S. Virgin Islands > U. S. Virgin Islands (17N064W0000) OCEAN BASIN > Atlantic Ocean > Caribbean Sea > Virgin Islands > Lesser Antilles > U. S. Virgin Islands (17N064W0000) place CoRIS Place Thesaurus Caribbean Saint Croix Saint Thomas U.S. Virgin Islands place Geographic Names Information System DOC/NOAA/NOS/OCM > Office of Coastal Management, National Ocean Service, NOAA, U.S. Department of Commerce dataCentre Global Change Master Directory (GCMD) Data Center Keywords 2017-04-24 publication 8.5 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 22. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian Lidar project InPort otherRestrictions Cite As: Office for Coastal Management, [Date of Access]: EAARL-B Submerged Topography - Saint Croix and Saint Thomas, U.S. Virgin Islands, 2014 [Data Date Range], https://www.fisheries.noaa.gov/inport/item/48140. NOAA provides no warranty, nor accepts any liability occurring from any incomplete, incorrect, or misleading data, or from any incorrect, incomplete, or misleading use of the data. It is the responsibility of the user to determine whether or not the data is suitable for the intended purpose. otherRestrictions Access Constraints: None otherRestrictions Use Constraints: The U.S. Geological Survey requests to be acknowledged as originator of these data in future products or derivative research. otherRestrictions Distribution Liability: Any conclusions drawn from the analysis of this information are not the responsibility of USGS, USDA NRCS, NOAA, the Office for Coastal Management or its partners. unclassified Unclassified None vector eng; US elevation -65.27130878 -64.41490881 17.75629702 18.369432 | Currentness: Ground Condition 2014-03-07 | Currentness: Ground Condition 2014-03-08 | Currentness: Ground Condition 2014-03-11 | Currentness: Ground Condition 2014-03-12 | Currentness: Ground Condition 2014-03-13 | Currentness: Ground Condition 2014-03-14 | Currentness: Ground Condition 2014-03-17 | Currentness: Ground Condition 2014-03-18 | Currentness: Ground Condition 2014-03-19 | Currentness: Ground Condition 2014-03-21 | Currentness: Ground Condition 2014-03-24 Raw lidar data are not in a format that is generally usable by natural-resource managers and research 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 originally by a USGS-NASA collaborative project. Specialized processing algorithms are used to convert raw waveform lidar data acquired by the EAARL-B to georeferenced spot (x,y,z) returns for "first surface" and "bare earth" topography. The terms first surface and bare earth refer to the digital elevation data of the terrain, but although first-surface data include vegetation, buildings, and other man-made structures, bare-earth data do not. The zero crossing of the second derivative (that is, detection of stationary points) is used to detect the first return, resulting in "first surface" topography, whereas the trailing edge algorithm (that is, the algorithm searches for the location before the last return where direction changes along the trailing edge) is used to detect the range to the last return, or "bare earth" (the first and last returns being the first and last significant measurable part of the return pulse). Statistical filtering, known as the Random Consensus Filter (RCF), is used to remove false bottom returns and other outliers from the EAARL-B 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 GEOID12A model). Funding was from the NOAA Coral Reef Conservation Program. false eng false http://pubs.usgs.gov/of/2009/1078/ Zip Zip LAS/LAZ - LASer Zip Office for Coastal Management 2234 South Hobson Avenue Charleston SC 29405-2413 https://www.coast.noaa.gov/ WWW:LINK-1.0-http--link Office for Coastal Management Website Website listed for Office for Coastal Management information distributor https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=4940 WWW:LINK-1.0-http--link Customized Download Create custom data files by choosing data area, product type, map projection, file format, datum, etc. download https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4940/index.html WWW:LINK-1.0-http--link Bulk Download Simple download of data files. download dataset Accuracy The expected accuracy of the measured variables is as follows: attitude within 0.05 degree and 3 centimeters nominal ranging accuracy. Quality checks are built into the data-processing software. Horizontal Positional Accuracy Raw elevation measurements have been determined to be within 1 meter in horizontal accuracy. Vertical Positional Accuracy Typical vertical elevation accuracies for these data are consistent with the point elevation data; however, a ground-control survey is not completed simultaneously with every lidar survey. Vertical accuracies may differ based on the type of terrain and the accuracy of the GPS and aircraft-attitude measurements. Completeness Report Missing 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. Conceptual Consistency These data are located in UTM Zone 20. The data were collected using a Cessna 310 aircraft. The EAARL-B laser scanner collects the data using a green-wavelength (532-nanometer) 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. The navigational data are processed and then, along with the raw data, are downloaded into ALPS, or the Airborne Lidar Processing System (20140311-20141121). Data are converted from units of time to x,y,z points for elevation and formatted into .las and .xyz files, and the derived surface data are converted into raster data (GeoTIFFs). 2014-11-21T00:00:00 The data were depth calibrated in ALPS (20150106) using a linear model with a slope of 0.98103 and an intercept of -0.000681. 2015-01-06T00:00:00 Metadata imported into ArcCatalog 10.1.1.3143 from XML file. 2015-07-06T00:00:00 Data were received by the NOAA Office for Coastal Management from Tim Battista and imported into the Digital Coast Data Access Viewer system. Data were reprojected from UTM 20N to geographic coordinates. Vertical values were transformed from orthometric to ellipsoid heights using the NGS GEOID12a model. Compression to an LAZ file was done with the LAStools 'laszip' program and can be unzipped with the same free program (laszip.org) 2015-07-07T00:00:00 Office for Coastal Management processor Lidar data USGS originator