gov.noaa.nmfs.inport:48169 eng UTF8 dataset National Geodetic Survey 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 2026-03-04T19:17:17 ISO 19115-2 Geographic Information - Metadata Part 2 Extensions for imagery and gridded data ISO 19115-2:2009(E) 2014 NOAA NGS Topobathy Lidar: Connecticut 2015-12-18 publication NOAA/NMFS/EDM 48169 https://www.fisheries.noaa.gov/inport/item/48169 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 Digital Coast Data Access Viewer Online Resource download https://coast.noaa.gov/ WWW:LINK-1.0-http--link Office for Coastal Management Online Resource download These data were collected by the National Oceanic Atmospheric Administration National Geodetic Survey Remote Sensing Division using a Riegl VQ820G system. The data were acquired from 20140502- 20140526 in fourteen missions. The data includes topobathy data in an LAS 1.2 format file classified as unclassified (1), ground (2), topo noise (7), refracted High Water data landward of the MLLW land/water interface (19), water column (25), bathymetric bottom or submerged topography (26), water surface (27), and International Hydrographic Organization (IHO) S-57 objects (31), in accordance with project specifications. The project consists of 58 square miles along the Atlantic Coast in Connecticut and a small portion of Rhode Island. Digital Elevation Models (DEMs) created from this data are available. These products have not been reviewed by the NOAA Office for Coastal Management and any conclusions drawn from the analysis of this information are not the responsibility of NOAA or the Office of Coastal Management (OCM). The data are available upon request via email at: coastal.info@noaa.gov. Please provide the name of the data set and "DEM Request" in the subject line. Original contact information: Contact Org: National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), National Geodetic Survey (NGS), Remote Sensing Division Title: Chief, Remote Sensing Division Phone: 301-713-2663 This lidar data was required by the National Geodetic Survey (NGS), Remote Sensing Division Coastal Mapping Program (CMP) to enable accurate and consistent measurement of the national shoreline. The CMP works to provide a regularly updated and consistent national shoreline to define America's marine territorial limits and manage coastal resources. We request that you credit the National Oceanic and Atmospheric Administration (NOAA) when you use these data in a report, publication, or presentation. 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/geoid18/4973/supplemental/ct2014_ngs_topobathy_ct_m4973.kmz This graphic shows the lidar footprint for the 2014 NOAA NGS topobathy lidar project in Connecticut and a small part of Rhode Island. kmz EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION > TOPOGRAPHICAL RELIEF MAPS EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > BATHYMETRY EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > SEAFLOOR TOPOGRAPHY EARTH SCIENCE > OCEANS > COASTAL PROCESSES > COASTAL ELEVATION theme Global Change Master Directory (GCMD) Science Keywords 17.0 CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > CONNECTICUT CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > RHODE ISLAND place Global Change Master Directory (GCMD) Location Keywords 20.8 20140502 20140503 20140504 20140506 20140507 20140512 20140513 20140514 20140518 20140519 20140520 20140521 20140524 20140526 temporal DOC/NOAA/NOS/NGS > National Geodetic Survey, 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 NGS Lidar project InPort otherRestrictions Cite As: National Geodetic Survey, [Date of Access]: 2014 NOAA NGS Topobathy Lidar: Connecticut [Data Date Range], https://www.fisheries.noaa.gov/inport/item/48169. 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: 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. otherRestrictions Distribution Liability: Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the National Geodetic Survey (NGS), the Office for Coastal Management or its partners. unclassified NOAA Data Management Plan (DMP) NOAA/NMFS/EDM 48169 https://www.fisheries.noaa.gov/inportserve/waf/noaa/nos/ngs/dmp/pdf/48169.pdf WWW:LINK-1.0-http--link NOAA Data Management Plan (DMP) NOAA Data Management Plan for this record on InPort. information crossReference vector eng; US elevation OS Independent -72.058244 -71.807748 41.237427 41.399689 | Currentness: Ground Condition 2014-05-02 2014-05-26 Data include all lidar returns. An automated grounding classification algorithm was used to determine bare earth and submerged topography point classification. The automated grounding was followed with manual editing. The intensity imagery were created from the full point cloud excluding noise. false eng false Other NOAA NGS Topobathy Lidar Class Scheme: Connecticut 2024-02-01 publication Zip Zip LAS/LAZ - LASer Zip 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 distributor https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=4973 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/geoid18/4973/index.html WWW:LINK-1.0-http--link Bulk Download Simple download of data files. download dataset Horizontal Positional Accuracy Project specifications require horizontal positions to meet 1.0m RMSE.; Quantitative Value: 1 meters, Test that produced the value: Independent horizontal accuracy testing requires photo-identifiable survey checkpoints, which is not always possible with elevation data. Survey photos were not delivered with the provided control points so the control point locations could not be identified in the LiDAR intensity imagery and horizontal accuracy could not be computed for the lidar data. The LiDAR data is compiled to meet the 1.0 m RMSE horizontal accuracy specification through rigorous processing of airborne GPS and IMU, use of control, and calibration procedures. Vertical Positional Accuracy The vertical accuracy of the LiDAR was verified by Dewberry with 31 control points provided by NOAA. Three of these points were located outside of the LiDAR coverage so 28 control points were used in the vertical accuracy testing. The vertical accuracy is tested by comparing the control points to a triangulated irregular network (TIN) that is created from the LiDAR points. Control points are always compared to interpolated surfaces created from the LiDAR point cloud because it is unlikely that a control point will be located at the location of a discrete LiDAR point. Control points in open terrain, bare earth, or urban areas will be used to compute the Fundamental Vertical Accuracy (FVA). Project specifications require a FVA of 0.245 m at the 95% confidence level based on RMSEz (0.125 m) x 1.9600. As only control points were provided to verify the vertical accuracy, only FVA could be verified on this dataset.; Quantitative Value: 0.122 meters, Test that produced the value: Based on the vertical accuracy testing conducted by Dewberry, using NSSDA and FEMA methodology, vertical accuracy at the 95% confidence level (called Accuracyz) is computed by the formula RMSEz x 1.9600. The CT Topobathy dataset satisfies the criteria: Lidar dataset tested 0.239 m vertical accuracy at 95% confidence level in open terrain, based on RMSEz (0.122 m) x 1.9600. Completeness Report Original data covered 637 tiles (500m x 500m tiles). During Digital Coast processing, points that were classified as noise (22,23,24) were dropped from the data set. 14 of the 637 files had only noise points. These 14 files were dropped from the data set. Only 623 files in the Digital Coast. Conceptual Consistency Not applicable Data for the CT Topobathy LiDAR project was acquired by NOAA using a Riegl VQ-820G Topobathy LiDAR systems. All delivered LiDAR data is referenced to: Horizontal Datum-NAD83 (2011) epoch: 2010 Projection-UTM Zone 19 Horizontal Units-meters Vertical Datum-NAD83 (2011) epoch: 2010 (ellipsoid heights) Vertical Units-meters This dataset encompasses 637 500m x 500m tiles in Connecticut and Rhode Island. Both green LiDAR data and NIR LiDAR data (used for water surface model creation that is incorporated during refraction of the green bathymetric data) was acquired. NOAA acquired and calibrated the LiDAR data. Dewberry received the calibrated green and NIR data and verified complete coverage. Relative accuracy of the green swaths compared to overlapping and adjacent green swaths as well as the relative accuracy of green swaths compared to overlapping and adjacent NIR swaths was verified through the use Delta-Z (DZ) orthos created in GeoCue software. Dewberry used E-Cognition to create 2D breaklines representing land/water interfaces. These 2D breaklines were manually reviewed and adjusted where necessary to ensure all well-defined hydrographic features (at 1:1200-scale) were represented with breaklines. Using TerraScan, all green LiDAR data within breaklines are classified as water column and a sub-set of these points meeting specific criteria are classified as green water surface points. Using TerraScan, all NIR LiDAR data within breaklines are classified as water column and a sub-set of these points meeting specific criteria are classified as NIR water surface points. Dewberry used the green water surface points and NIR water surface points to create water surface models. These models are used in the refraction tool to determine the depth of bathymetric points and are created for single swaths to ensure temporal differences and wave or water surface height variations between flight lines do not impact the refraction of the bathymetric data. 2015-06-01T00:00:00 Using the SBET data and the water surface models, all green LiDAR data classified as water column (data within the breaklines) is refracted using Dewberry's LiDAR Processor (DLP). Light travels at different speeds in air versus water and its direction of travel or angle is changed or refracted when entering the water column. The refraction tool corrects for this difference by adjusting the depth (distance traveled) and horizontal position (change of angle/direction) of the green LiDAR data. Using statistics and limited manual review, the output data is verified to ensure the refraction tool functioned properly. Once all green data has been refracted by flight lines, all flight lines covering each tile are combined into a single 500 m x 500 m tile. As the various flight lines may include data collected at Mean Lower Low Water (MLLW) and higher water (HW), which includes everything that is outside the range of MLLW, any HW refracted data points landward of the MLLW land/water interface were classified to class 18 to ensure these HW bathymetric points were not used when MLLW exposed ground points exist in those locations. Dewberry used algorithms in TerraScan to create the initial ground/submerged topography surface. Dewberry then performed manual editing to review and improve the final topobathy surface. Locations of temporal differences were resolved using the Temporal Difference Decision Tree approved by NOAA. Polygons marking the locations of large temporal differences are provided as part of the deliverables. All LiDAR data was peer-reviewed. Dewberry's internal QC also included creating void polygons for use during review. All necessary edits were applied to the dataset. GeoCue software was used to update LAS header information, including all projection and coordinate reference system information. The final LiDAR data are in LAS format 1.2 and point data record format 3. The final classification scheme is as follows: 1-Unclassified 2-Ground 7-Topo Noise 18-Refracted High Water data landward of the MLLW land/water interface 22-Bathy Noise 23-Sensor Noise (as defined by the sensor using Riegl's noise classifier) 24-Refracted Sensor Noise 25-Water Column 26-Bathymetric Bottom or Submerged Topography 27-Water Surface 30-International Hydrographic Organization (IHO) S-57 objects 31-Temporal Bathymetric Bottom Dewberry then produced the final void layer and final set of DZ orthos using the final ground (2) and submerged topography (26) classes. All data is then verified by an Independent QC department within Dewberry. The independent QC is performed by separate analysts who do not perform manual classification or editing. The independent QC involves quantitative and qualitative reviews. 2015-06-01T00:00:00 The NOAA Office for Coastal Management (OCM) received 637 files in las format from NGS. The files contained lidar elevation and intensity measurements. The data were in UTM Zone 19 projection coordinates and ellipsoid heights in meters. OCM performed the following processing for data storage and Digital Coast provisioning purposes: 1. LAS files were compressed to laz format using laszip. 2. Data were checked for elevation outliers and points with elevation values less than -100 m were dropped from the data set. 3. Class 18 points (refracted high water data landward of the MLLW land/water interface) were reclassified to class 19 and class 30 points (IHO S-57 objects) were reclassified to class 31. 4. Noise points classified as 22 (bathy noise), 23 (noise as defined by the sensor), and 24 (refracted sensor noise) were dropped from the data set. NOTE: Because three noise classes were dropped from the data set, 14 files which only contained noise points, were dropped from the original number of 637 files. Number of files in the Digital Coast are 623. 5. Data were converted from UTM Zone 19 coordinates to geographic coordinates. 2015-11-10T00:00:00 Office for Coastal Management processor Lidar