49854 nj2006_hunterdon_m547_metadata Data Set Published / External 49401 Lidar - partner (no harvest) Project Completed 2007-02-26 This metadata record describes the lidar topographic elevation mapping of Hunterdon County, NJ that occurred in July 2006. Products generated include lidar point clouds in LAS 1.0 collected with a Leica ALS-50 Aerial Lidar Sensor. Original contact information: Contact Name: Angela R. Worley Contact Org: EarthData International Title: Project Manager Phone: 301-948-8550 x222 Email: aworley@earthdata.com The purpose of this data is to support floodplain mapping efforts as part of FEMA's Map Modernization Program. 10498 Watershed Concepts requested the collection of lidar data over Hunterdon County, NJ. In response, EarthData acquired the data on July 17, 2006 using its aircraft with tail number N806CP. Lidar data was acquired using an ALS-50 Lidar Sensor, including an inertial measuring unit (IMU) and a dual frequency GPS receiver. An additional GPS receiver was in constant operation over a published control point set by EarthData at the base of the operations airport which is a secondary airport control station. Terrasurv was tasked to perform a geodetic control survey in support of lidar mapping in Hunterdon County, NJ. The Global Positioning System (GPS) was used in static differential mode to measure the intersection vectors of the network. In addition to six locations chosen for control, a survey point located at the Lehigh valley International Airport was included in the network. This latter station was used a base station by the flight crew during data acquisition. The horizontal datum was the North American Datum of 1983-CORS (NAD83 CORS) and the vertical datum was the North American Vertical Datum of 1988. During the data acquisition, the receivers collected phase data at an epoch rate of 1 Hz. The use of the airport base station ensured that all data capture was within 50 miles of a base station. The solutions from Hunterdon County, NJ were found to be of high integrity and met the accuracy requirements for the project. These accuracy check also verified that the data meets the guidelines outlined in FEMA's Guidelines and Specifications for Flood Hazard Mapping Partners and Appendix 4B, Airborne Light detection and Ranging Systems. The areas of interest were flown at an altitude of 8500 feet above mean terrain. Airspeed - 145 knots; Laser Pulse Rate - 38000 Hz; Field of View - 40 degrees; Scan Rate - 20 Hz; Swath Width - 1996 meters A footprint of this data set may be viewed in Google Earth at: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/547/supplemental/2006_FEMA_NJ_Lidar_Hunterdon_County.kmz Theme ISO 19115 Topic Category elevation Theme bare earth Theme floodplain Office for Coastal Management Charleston SC Data Set Unknown Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the Office for Coastal Management or its partners. Data Steward 2007-02-26 Organization NOAA Office for Coastal Management NOAA/OCM coastal.info@noaa.gov 2234 South Hobson Ave Charleston SC 29405-2413 (843) 740-1202 https://coast.noaa.gov NOAA Office for Coastal Management Home Page Online Resource Distributor 2007-02-26 Organization NOAA Office for Coastal Management NOAA/OCM coastal.info@noaa.gov 2234 South Hobson Ave Charleston SC 29405-2413 (843) 740-1202 https://coast.noaa.gov NOAA Office for Coastal Management Home Page Online Resource Metadata Contact 2007-02-26 Organization NOAA Office for Coastal Management NOAA/OCM coastal.info@noaa.gov 2234 South Hobson Ave Charleston SC 29405-2413 (843) 740-1202 https://coast.noaa.gov NOAA Office for Coastal Management Home Page Online Resource Point of Contact 2007-02-26 Organization NOAA Office for Coastal Management NOAA/OCM coastal.info@noaa.gov 2234 South Hobson Ave Charleston SC 29405-2413 (843) 740-1202 https://coast.noaa.gov NOAA Office for Coastal Management Home Page Online Resource Ground Condition -75.195215 -74.703495 40.787876 40.339414 Discrete 2006-07-17 Yes Unclassified This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer; 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. https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=547 Customized Download Create custom data files by choosing data area, product type, map projection, file format, datum, etc. https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/547/index.html Bulk Download Simple download of data files. 2016-05-23 Date that the source FGDC record was last modified. 2017-11-14 Converted from FGDC Content Standard for Digital Geospatial Metadata (version FGDC-STD-001-1998) using 'fgdc_to_inport_xml.pl' script. Contact Tyler Christensen (NOS) for details. 2018-02-08 Partial upload of Positional Accuracy fields only. 2018-03-13 Partial upload to move data access links to Distribution Info. Lidar data was collected and processed in accordance with FEMA guidance and specifications, as published in Appendix A: Guidance for Aerial Mapping and Surveying, April 2003. The lidar data fully comply with FEMA guidance as published in Appendix A: Guidance for Aerial Mapping and Surveying, April 2003. The lidar data fully comply with FEMA guidance as published in Appendix A: Guidance for Aerial Mapping and Surveying, April 2003 and the National Standard for Spatial Accuracy (NSSDA). When compared to GPS survey grade points in generally flat non-vegetated areas, at least 95% of the positions have an error less than or equal to 36.3 cm (equivalent to a RMSEz of 18.5 if errors are normally distributed). - EarthData's proprietary software, Checkedb, was used for verification against ground survey points. - Verification of automated and manual editing, and final QC of products, was performed using Terrascan. Compliance with the accuracy standard was ensured by the placement of GPS ground control points prior to lidar data acquisition. The following checks were performed: - The ground control and airborne GPS data stream were validated through a fully analytical boresight analysis. - The Digital Terrain Model (DTM) data were checked against the project control. - Lidar elevation data was validated through an inspection of edge matching and visual inspection for quality (artifact removal). Hunterdon County, New Jersey FEMA Flood Mitigation LiDAR 2007-02-26 Discrete 2006-07-17 http://www.earthdata.com/ LiDAR data Hunterdon County, New Jersey FEMA Flood Mitigation LiDAR | Type of Source Media: hard drive 1 EarthData has developed a unique method for processing lidar data to identify and remove elevation points falling on vegetation, buildings, and other non-ground structures. The algorithms for filtering data were utilized within EarthData's proprietary software and commercially available software written by TerraSolid. This software suite of tools provides efficient processing for small to large scale projects and has been incorporated into ISO 9001 compliant production workflows. The following process was employed: - Using the lidar data provided by EarthData, the technician performed calibrations of the data. - Using the lidar data provided by EarthData, the technician performed a visual inspection of the data verify that the flight lines overlap correctly. The technician also verified that there were no voids, and that the data covered the project limits. The technician then selected a series of areas from the data set and inspected them where adjacent flight lines overlapped. These overlapping areas were merged and a process which utilizes ArcGIS 3D Analyst and EarthData's proprietary software was run to detect and color code the differences in elevation values and profiles. The technician reviewed these plots and located the areas that contained systematic errors or distortions that were introduced by the lidar sensor. - Identified systematic distortions were removed and the data were re-inspected. Corrections and adjustments can involve the application of angular deflection or compensation for curvature of the ground surface that can be introduced by crossing from one type of land cover to another. - The lidar data for each flightline was trimmed for the removal of the overlap areas between flightlines. The data was checked against a control network to ensure that vertical requirements were maintained. Conversion to the client-specified datum and projections were then completed. The lidar flightline datasets were then tiled for batch processing and data management. - The initial batch processing removed 95% of points falling on vegetation. The algorithm also removed the points that fell on the edges of hard features such as buildings, elevated roadways and bridges. - The technician interactively processed the data using lidar editing tools. During this final phase, the data was TINed based on desired thematic layers to evaluate the automated classification previously performed. This allowed the technician to quickly reclassify points from one layer to another and recreate the TIN surface to see the effect of edits. Georeferenced images were toggled on and off to aid in identification of problem areas. The data were also examined with an automated profiling tool to aid in reclassification. - The final DEM was written to las 1.0. - The point cloud data delivered in las 1.0 2007-02-26T00:00:00 2 The NOAA Office for Coastal Management (OCM) received the files in las format. The files contained Lidar elevation and intensity measurements. The data were projected in New Jersey State Plane coordinates, and referenced to NAVD88 using Geoid 03. OCM performed the following processing steps to the data to make it available within the Digital Coast: 1. The data were converted from New Jersey State Plane (NAD83) coordinates to geographic coordinates (NAD83). 2. The data were converted from NAVD88 (orthometric) heights to GRS80 (ellipsoid) heights using Geoid 03. 3. The LAS data were sorted by latitude and the headers were updated. 2010-09-22T00:00:00 gov.noaa.nmfs.inport:49854 Anne Ball 2017-11-15T15:22:46 SysAdmin InPortAdmin 2022-08-09T17:11:38 2022-03-16 OCM Partners OCMP 1002 Public No No 2022-03-16 1 Year 2023-03-16