49783 md2005_m32_metadata Data Set Published / External 49401 Lidar - partner (no harvest) Project Completed 2005-01-20 Light Detection and Ranging (LIDAR) is a method of locating objects on the ground using aerial-borne equipment. It is similar to RADAR or SONAR in that the two-way travel time of an energy beam reflected off an object is precisely measured, but this technology uses laser light instead of radio or sound waves. This technology has proven very useful in remote sensing of the earth. It can be used for determining elevations of both the earth's surface and items (natural and man-made) on the surface. Analysis of LIDAR data is used in detailed modeling of the earth's surface for drainage and floodplain studies, determining how a new structure will affect views from various locations, shoreline erosion studies, and other reasons. This data set contains only the bare earth mass points. Bare earth points represent ground features. Features that are above ground, such as buildings, bridges, tree tops, etc, have been eliminated. Mass points may appear to have "holes" with no elevation values in areas where the surface could not be determined, such as very dense forests or urban areas. Original contact information: Contact Name: Ken Miller Contact Org: Maryland Department of Natural Resources Title: Chief. Watershed Information Services Division Phone: 410-260-8751 Email: kenmiller@dnr.state.md.us The LIDAR-derived data were collected by the Maryland Department of Natural Resources in support of shore erosion studies along the shorelines of the Chesapeake Bay. It also supports the Federal Emergency Management Agency's specifications for mapping floodplains. These efforts required detailed elevation data and models, such as those available from LIDAR sensing. The data have also been made available to aid in other projects that require detailed surface, vegetation and/or structure elevations. 10427 1. Airborne1, Inc. (flight firm) 2. Computational Consulting Services, LLC (processing firm) 3. Spatial Systems Associates, Inc. (post-processing firm) 4. Dewberry and Davis (QA/QC firm) These data are part of a suite of spatial data products generated using the LIDAR technology. First and Last returns are generated. From these data, Bare-Earth Mass Points that represent the earths surface are produced. A gridded Digital Elevation Model (DEM) is produced from the Bare Earth Mass Points. Imagery is also created that represents the intensity of the LIDAR return; it is a 1-meter resolution product that resembles a panchromatic Digital Orthophoto Quad (DOQ). The Cecil County, Maryland QA Report may be viewed at: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/32/supplemental/index.html Theme ISO 19115 Topic Category elevation Theme DNR General Bald earth Theme DNR General Bare earth Theme DNR General Bathymetry/Topography Theme DNR General DEM Theme DNR General DNR Theme DNR General Digital Elevation Model Theme DNR General Elevation and derived products Theme DNR General Elevation model Theme DNR General First return Theme DNR General Gridded DEM Theme DNR General LIDAR Theme DNR General Last return Theme DNR General Surface model Theme DNR General Terrain model Office for Coastal Management Charleston SC Data Set None Planned Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the OCM or its partners. Spatial Systems Associates, Inc. was the prime contractor for this project. It partnered with Airborne1, Inc., Computational Consulting Services, Inc., NXL Construction Services, Inc and Dewberry LLC. Data Steward 2005-01-20 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 2005-01-20 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 2005-01-20 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 2005-01-20 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 -76.24904 -75.75024 39.728895 39.357195 Range 2005-04-15 2005-04-23 Yes Unclassified This data set can be obtained online 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. The Department of Natural Resources makes no warranty, expressed or implied, as to the use or appropriateness of Spatial Data, and there are no warranties of merchantability or fitness for a particular purpose or use. The information contained in Spatial Data is from publicly available sources, but no representation is made as to the accuracy or completeness of Spatial Data. The Department of Natural Resources shall not be subject to liability for human error, error due to software conversion, defect, or failure of machines, or any material used in the connection with the machines, including tapes, disks, CD-ROMs or DVD-ROMs and energy. The Department of Natural Resources shall not be liable for any lost profits, consequential damages, or claims against the Department of Natural Resources by third parties. The liability of the Department of Natural Resources for damage regardless of the form of the action shall not exceed any distribution fees that may have been paid in obtaining Spatial Data. https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=32 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/geoid18/32/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 Standards 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. A variety of specialized hardware and software platforms were used to collect, process and quality assess these data. Typically, Intel machines running Microsoft Windows 2000 Version 5.0 (Build 2195) Service Pack 4. There are four (4) attributes in the Bare Earth Mass Points files, representing the horizontal coordinates (easting and northing) and vertical position observed and vertical assigned (see process description). Random inspections were made to assure that each line in the file contained 4 values. The horizontal coordinate values were designed to meet NSSDA accuracy for data at 1:2400 scale. The RMSE value of 9.3 cm at the 95% confidence level was determined by an independent accuracy assessment conducted by Dewberry LLC according to the contract specifications. These specifications followed FEMA Appendix A guidelines regarding assessing vertical accuracy. For data accurate to within 18.5 cm RMSE, the guidelines recommended a minimum of 20 independent check points be located in each of 5 different land cover categories: Grass/Ground, High Grass/Crops, Brush/Low Trees, Forest, and Urban/Pavement. A total of 100 points were used for the assessments. These points were surveyed by a licensed land surveyor and provided a positional location and elevation with an accuracy that exceeded the predicted accuracy of the LIDAR data. The entire accuracy reports can be found at http://dnrweb.dnr.state.md.us/gis/data/lidar. ; Quantitative Value: 9.3 meters, Test that produced the value: The RMSE value is 9.3 cm. See the Vertical Positional Accuracy Report section for more information. Cloud Cover: 0 Spatial Systems Associates performed various inspections of the data to ensure: that each file contained the points located within that tile; that tiles were completely filled; that the point density per tile was within expected ranges, and that the tiles were correctly named. Computational Consulting Services, the LIDAR processing vendor used proprietary algorithms to remove features and artifacts in the First and Last Return data that did not reflect true ground elevation. Subsequent quality assurance testing by Dewberry determined that the data met FEMA and MD DNR specifications for both vertical accuracy and other consistencies with accepted standards. The QA report can be accessed at http://dnrweb.dnr.state.md.us/gis/data/lidar. 1 LIDAR Data Acquisition. Airborne 1, Inc. flew the project area with the LIDAR sensor. In an effort to permit correlation of the point values with tidal gauge stations, Airborne 1, Inc. was required to fly tidal shoreline areas during the low tide cycle (slack water - low tide - slack water) as predicted by local tide stations. The LIDAR sensor collected raw data that was referenced in UTM. The flight plan on this project included the following specifications to meet the project requirements: *Single pass density - 1.544 square meters per sample; *Average area sampling density -1.52 square meters per sample; *Swath width - 891.32 meters; *Flight altitude -1371 meters (4500 ft); *Flight line spacing - 445.66 meters w/50% overlap; *Scan frequency - 22 Hz; *Firing rate - 25 kHz; *Scan angle - 18 degrees; *Ground speed - 130 knots. When complete, the raw data was delivered to Spatial Systems. 2005-04-24T00:00:00 2 LIDAR Data Processing. Computational Consulting Systems. The First and Last Return data was delivered to CCS in large blocks of data. CCS processed the data using both the First and Last Returns, removed artifacts using automated and manual techniques, and reprojected the data into the client-specified X, Y, Z text files using the 1200 meter x 1800 meter tiles, NAD 83 meters, NAVD 88 meters. CCS also generated the Intensity Imagery using the client-specified USGS 3.75' tiling scheme. The data products were delivered to SSA for quality assurance testing, formatting and final delivery. 2005-08-30T00:00:00 3 LIDAR Data Post Processing. Spatial Systems Associates. SSA digitized the shoreline from the Intensity Imagery for the purposes of delineating a shoreline. Any LIDAR points that fell seaward of this shoreline were assigned the value of zero (0). In addition to the shoreline, SSA delineated upland ponds using the same technique and assigned all LIDAR points that fell within the water area the value of the lowest observed point close to the shore. The observed elevation values were not lost; a fourth field in the data file was added for the assigned value. SSA also performed a variety of QA procedures to determine if the point density was within expected ranges; that each tile was completely filled; that all tiles were accounted for, and that the tiles were named in accordance with client specifications. 2005-09-30T00:00:00 4 LIDAR Data Check Point Surveys. NXL Construction Services. NXL was contracted to acquire the check-points in the 5 different land cover classes. SSA provided NXL with maps of each area where a check-point was to be located. The points were scattered throughout the project area. NXL was permitted the latitude to select the exact location based on field conditions, provided the points were generally within a 1 mile radius of the chosen location and that the land cover class was the same as the one specified. The land cover classes were: Grass/Ground, High Grass/Crops, Brush/Low Trees, Forest, and Urban/Pavement. 2005-06-30T00:00:00 5 LIDAR Data Quality Assurance. Dewberry LLC was provided with the check-point and LIDAR Bare Earth Mass Points data to perform their independent quality assurance work. They performed detailed analyses to determine if the vertical accuracy was within specifications and examined the data for flight, data collection and processing inconsistencies. Neither the flight vendor (Airborne 1) nor the processing vendor (CCS) was given access to the check-point data. The entire accuracy report can be found at http://dnrweb.dnr.state.md.us/gis/data/lidar. 2005-09-30T00:00:00 6 The NOAA Office for Coastal Management (OCM) received LAS files containing the point cloud elevation data from Earth Data, Inc. OCM performed the following processing on the data to make it available within the Lidar Data Retrieval Tool (LDART): 1. Variable length header records were added to the LAS files to identify projection, datum and sort order. 2. The LFIT files were sorted by latitude. 3. Lfit files were exported to xyz ASCII text. 2006-11-01T00:00:00 gov.noaa.nmfs.inport:49783 Anne Ball 2017-11-15T15:22:16 SysAdmin InPortAdmin 2022-08-09T17:11:36 2022-03-16 OCM Partners OCMP 1002 Public No No 2022-03-16 1 Year 2023-03-16