49728 ga2010_arc_dekalbcounty_m2527_metadata Data Set Published / External 49401 Lidar - partner (no harvest) Project Completed 2012-08-13 This metadata record describes the DTM comprised of classified aerial lidar elevation points, photogrammetrically compiled breaklines and the derived TIN for Dekalb County, GA Original contact information: Contact Name: Stacy Grear Contact Org: Dekalb County GIS Department Title: Acting Director Phone: 404-371-3619 Email: scgrear@dekalbcountyga.gov will change to scgrear@dekalbcountyga.gov on July 1, 2010 The lidar DEM data was collected for the Dekalb County, GA area. All lidar returns were classified using the default classes of Terrascan processing software for Unclassified Points (class 1), Ground points (class 2), Water points (class 9), Overlap points (class 12). The lidar ground points are supplemented with photogrammmetrically compiled breaklines from digital imagery collected during the same project time frame as the lidar. The ground class points, often refered to as "bald earth" are then used as an input to proprietary and publicly available processing software to generate a Triangulated Irregular Network (TIN) model. Classified lidar DEMs and derived TIN models are useful for a variety of applications, such as aiding in contour generation, development of digital surface models, 3D modeling, flood plane mapping, viewshed analysis and the production of orthophotos. 10373 A footprint of this data set may be viewed in Google Earth at: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/2527/supplemental/ga2010_dekalbcounty.KMZ A Lidar Report from the vendor for this data set may be viewed here: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/2527/supplemental/ga2010_dekalbcounty_QC_Report.pdf Theme ISO 19115 Topic Category elevation Theme TIN Theme Triangulated Irregular Network Theme mapping Office for Coastal Management Charleston SC Data Set Unknown Point and vector digital data LiDAR points in LAS 1.2 format none Any conclusions drawn from the analysis of this information are not the responsibility of Kucera International, ARC, USGS, NOAA, the Office for Coastal Management or its partners. Please credit the Deklab County GIS Department Puget with support from the Atlanta Regional Commission with this data. Data Steward 2012-08-13 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 2012-08-13 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 2012-08-13 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 2012-08-13 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 -84.35091417 -84.02334971 33.97061816 33.61447836 Discrete 2010-01-02 Discrete 2010-01-03 Yes Unclassified This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer The data set is dynamically generated based on user-specified parameters. ; 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. These data depict the heights at the time of the survey and are only accurate for that time. https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=2527 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/geoid18/2527/index.html Bulk Download Simple download of data files. https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/2527/supplemental/ga2010_dekalbcounty.KMZ Browse Graphic Browse Graphic kmz This graphic shows the lidar coverage for the 2010 Dekalb County Lidar Survey in Georgia. https://coast.noaa.gov Online Resource https://coast.noaa.gov/dataviewer Online Resource 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. Attribute accuracy is tested in the LiDAR processing stage. After classification of the LiDAR data, the 'bald earth' point class is compared to ground control collected within the project area. Horizontal positional accuracy for LiDAR is dependent upon the quality of the GPS/INS solution, sensor calibration and ground conditions at the time of data capture. The standard system results for horizontal accuracy are less than 1 meter.; Quantitative Value: 1 meters, Test that produced the value: This value is computed by comparing ground control to an intensity based image derived from the classified LiDAR data and represents the RMSE of residuals on controls within the project area. Vertical positional accuracy for LiDAR is dependent upon the quality of the GPS/INS solution, sensor calibration and ground conditions at the time of data capture. The vertical accuracy for this project was tested with a resultant RMSE of 0.057 meter (0.188 feet).; Quantitative Value: 0.057 meters, Test that produced the value: This value is computed by comparing ground control elevation to the classified LiDAR ground surface and represents the RMSE of residuals on controls within the project area. Units = meters. LiDAR data is collected for the project area. Post processing of the simultaneously acquired GPS/INS is performed and applied to the laser returns to output a point cloud in the specified project coordinate system and datums. The point cloud data is then subjected to automated classification routines to assign all points in the point cloud to ground, water, overlap and unclassified point classes. Anomalous laser returns that occur infrequently are removed entirely from the data set. The ground class points are then compared to surveyed ground control to develop an accuracy measure of the laser terrain data. LiDAR data is collected within the project area, processed and verified against control. Aerial Digital Imagery Discrete 2010-02-18 New digital aerial imagery and GPS/IMU data was recorded for the defined project area. | Source Geospatial Form: Remote sensing image | Type of Source Media: disc Ground control 2010-01-01 Discrete 2010 Targeted ground control is used to create a digital control file and control report as well as QC check of LiDAR accuracy. Predefined points (NGS when available) within the project area are targeted. | Source Geospatial Form: tabular digital data | Type of Source Media: disc LiDAR Data Discrete 2010-01-02 Aerial LiDAR and GPS/IMU data was recorded for the defined project area. | Source Geospatial Form: Remote sensing image | Type of Source Media: disc Triangulated Irregular Network 2010-01-01 Discrete 2010 Using the lidar elevation points and compiled breaklines as inputs, a Triangulated Irregular Network (TIN) is generated using ESRI ArcGIS software. | Source Geospatial Form: Vector digital data | Type of Source Media: disc 1 At selected locations throughout the site, accurate GPS coordinates and elevations are surveyed and the points are marked with targets. 2010-01-01T00:00:00 10 The Traingulated Irregular Network is generate with ESRI ArcGIS software. 2010-01-01T00:00:00 11 The NOAA Office for Coastal Management (OCM) received topographic files in LAS format. The files contained lidar elevation and intensity measurements. The data were received in projected Georgia State Plane West Zone 1002 coordinates and were vertically referenced to NAVD88. The vertical units of the data were feet. OCM performed the following processing for data storage and Digital Coast provisioning purposes: 1. The LAS files were processed through a lastools program known as LASGround, where an algorithm further processes any unclassified points to the ground class, ignoring pre-exisint ground points. 2. All files were then horizontally shifted from the projected GA_W (1002) state place coordinates (in feet) to geographic NAD83 coordinates (decimal degrees) 3. All files were then vertically shifted from from orthometric NAVD88 heights (feet) to ellipsoidal NAD83 (meters) using GEOID09 (assumed based on processing date) 2013-08-09T00:00:00 2 New LiDAR data is captured for the project area using a Leica ALS60 LiDAR instrument in conjunction with a POSAV Applanix GPS/INS system mounted within a Piper Navajo twin engine airplane. 2010-01-01T00:00:00 3 New aerial digital imagery with airborne GPS/IMU data is acquired for the project area. 2010-01-01T00:00:00 4 The airborne GPS data is processed in Terratec TerraPos software and then combined with the IMU data in Applanix PosPAC software to determine the LiDAR sensor's angle and orientation in the terrain (project) coordinate system and datums during the survey. The same GPS/IMU processing is performed for the digital imagery to define the orientation parameters of the images to be used in stereo compilation of terrain breaklines. 2010-01-01T00:00:00 5 LiDAR data is processed using the GPS/INS solution. Data is classified to produce: Class 1: unclassified points Class 2: ground points Class 9: water points Class 12: overlap points 2010-01-01T00:00:00 6 The ground class of the processed lidar data is then compared to the ground control and elevation differences between the lidar surface and surveyed elevation are recorded in tabular form. Vertical accuracy statistices are then developed to produce vertical RMSE and overall accuracy estimates and reports. 2010-01-01T00:00:00 7 Photogrammetrically compiled breaklines are compiled to supplement the lidar ground points. 2010-01-01T00:00:00 8 Water polygons are buffered to remove any lidar points within the polygon to flatten these surfaces. 2010-01-01T00:00:00 9 Breaklines are buffered to remove lidar surface points on or near the breakline. 2010-01-01T00:00:00 gov.noaa.nmfs.inport:49728 Anne Ball 2017-11-15T15:21:54 SysAdmin InPortAdmin 2022-08-09T17:11:37 2022-03-16 OCM Partners OCMP 1002 Public No No 2022-03-16 1 Year 2023-03-16