Woolpert201505292015 NCTCOG Program Lidar Classified LAS 1.2Lidar point cloudTASK NAME: 2015 NCTCOG Program
Lidar Data Acquisition and Processing Production Task
Woolpert Order No. 74759
CONTRACTOR: Woolpert, Inc.
This data set is comprised of lidar point cloud data, raster DEM, raster DSM, classified XYZ, hydrologic 3-d breaklines, raster intensity, survey control, project tile index, and project data extent. This task order requires lidar data to be acquired in the NCTCOG region including 16 counties consisting of Dallas, Tarrant, Collin, Denton, Rockwall, Kaufman, Wise, Johnson, Hood,
Erath, Hunt, Navarro, Ellis, Somervell, Palo Pinto, and Parker, which cover approximately 12,800 square miles. The lidar data will be acquired and processed under the requirements identified in this task order. Lidar data is a remotely sensed high resolution elevation data collected by an airborne platform. The lidar sensor uses a combination of laser range finding, GPS positioning, and inertial measurement technologies. The lidar systems collect data point clouds that are used to produce highly detailed Digital Elevation Models (DEMs) of the earth's terrain, man-made structures, and vegetation. The task required the LiDAR data to be collected at a nominal pulse spacing (NPS) of 0.5 meters. The final products include classified LAS, two (2) feet pixel raster DEMs of the bare-earth surface in ERDAS IMG Format, two (2) feet pixel raster DSMs in ERDAS IMG Format and 8-bit intensity images. Each LAS file contains lidar point information, which has been calibrated, controlled, and classified. Additional deliverables include hydrologic breakline data, control data, tile index, lidar processing and survey reports in PDF format, FGDC metadata files for each data deliverable in .xml format, classified XYZ , LAS swath data and flightline shapefiles. Collected swath files that were that were larger than 2GB were provided in multiple sub-swath files, each less than 2GB. Ground conditions: Water at normal levels; no unusual inundation; no snow; leaf off.
USGS NGP Base Specifications v1Leica ALS7040.5419811352849.6292.055106410.22144230NAD1983 Texas Stateplane North Central Zone FeetGEOID091.100.4311.21Geometrically unreliable points were identified using a combination of automated and manual techniques and subsequently classified as swath overlap and or noise.swath overlap points were identified in these files by adding 16 to the standard classication values81default/unclassified2Bare-earth3Low vegetation4Medium vegetation5High vegetation6Building7All noise9Water17Overlap default/unclassified18Overlap groundThe purpose of this project is to provide orthoimagery, LiDAR, and contour services for the 2015 project.20150106201501072015010820150115201501162015011720150118201501192015012020150123201501242015012520150126201501272015012820150129ground conditionAs needed-97.646519-96.30127033.36605932.261165NonelidarClassified LAS 1.2NoneUnited StatesTexasNo restrictions apply to this data.None. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no longer represent actual surface conditions. Woolpertmailing and physical address
4454 Idea Center Blvd
DaytonOH45430USA(937) 461-5660(937) 461-07438:00 a.m. to 5:00 p.m. Eastern Standard TimeMicrosoft Windows 7 Version 6.1 (Build 7600); ArcMap 10.2; ArcCatalog 10.2; TerraScan ver. 14.003; TerraModeler ver. 14.003; Geocue 2012.1.27.5; LP360 2011.1.54.1. Approximate size of entire delivery dataset = 3.5 TBAll formatted data cover the entire area specified for this project and are validated using a combination of commercial lidar processing software, GIS software, and proprietary programs to ensure proper formatting and loading prior to delivery.The lidar data is visually inspected for completeness to ensure that are no void areas or missing data.Compiled to meet 1.10 feet horizontal accuracy at 95 percent confidence level.1.100 feetLidar system specifications are available in the project reportLAS data covering the NCTCOG 2015 Program Lidar 0.5 meter NPS Lidar Task Order was compared to independent survey control points to determine the FVA of the LAS Swath and of the Bare-Earth DEM. Raw LAS Swath Fundamental Vertical Accuracy (FVA) Tested 0.431 feet fundamental vertical accuracy at a 95 percent confidence level, derived according to NSSDA, in open terrain using 0.220 feet (RMSEz) x 1.96000 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines. Bare-Earth DEM Fundamental Vertical Accuracy (FVA) Tested 0.410 feet fundamental vertical accuracy at a 95 percent confidence level, derived according to NSSDA, in open terrain using 0.209 feet (RMSEz) x 1.96000 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines.0.431 feetLAS Swath Fundamental Vertical Accuracy (FVA) Tested 0.431 feet fundamental vertical accuracy at a 95 percent confidence level, derived according to NSSDA, in open terrain using (RMSEz) x 1.96000 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines and tested against the TIN.
0.410 feetBare-Earth DEM Fundamental Vertical Accuracy (FVA) Tested 0.410 meters fundamental vertical accuracy at a 95 percent confidence level, derived according to NSSDA, in open terrain using (RMSEz) x 1.96000 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines and tested against the DEM.Woolpert20150529Lidar acquisitionDayton, OHWoolpert Geospatial ServicesLidar dataset20150106ground condition2015 NCTCOG Program Lidar This data set is the project specified acquired point cloud data.Woolpert20150529Survey Control AcquistionAustin, TexasGorrondona & Associates, IncControl dataset20150112ground condition2015 NCTCOG Program Lidar This data set is the project specified acquired ground control and QAQC control data.Woolpert20150529Lidar deliverable processingDayton, OHWoolpert Geospatial ServicesLidar dataset20150107ground condition2015 NCTCOG Program Lidar This data set is the project specified lidar deliverables.Using one Leica ALS70 (lidar) system on board a Cessna 310 aircraft, high density data, at a nominal pulse spacing (NPS) of 0.5 meters, were collected for this task order (approximately 12,800 square miles). Leica Specs- AGL = Varies - Aircraft Speed = 135 Knots, Field of View (Full) = 28 degrees, Pulse Rate = 292 kHz, Scan Rate = 49.6 Hz, with an average side lap of 30%. Multiple returns were recorded for each laser pulse along with an intensity value for each return. Twenty-one (21) missions were flown between January 6, 2015 and January 29, 2015. Five (5) Global Navigation Satellite System (GNSS) Base Stations were used in support of the lidar data acquisition. Specific information regarding latitude, longitude, and ellipsoid height to the L1 phase center is included in the lidar processing report. The geoid used to reduce satellite derived elevations to orthometric heights was GEOID12A. Data for the task order is referenced to the North American Datum 1983 (NAD83),Texas State Plane Coordinate System, North Central Zone, and expressed in U.S. Survey Feet. The vertical datum used for this survey will be North American Vertical Datum 1988 (NAVD88). Once the data acquisition and GPS processing phases are complete, the lidar data was processed immediately to verify the coverage had no voids. The GPS and IMU data was post processed using differential and Kalman filter algorithms to derive a best estimate of trajectory. The quality of the solution was verified to be consistent with the accuracy requirements of the project. The SBET was used to reduce the lidar slant range measurements to a raw reflective surface for each flight line. The coverage was classified to extract a bare earth digital elevation model (DEM) and separate last returns. The ALS70 calibration and system performance is verified on a periodic basis using Woolpert's calibration range. The calibration range consists of a large building and runway. The edges of the building and control points along the runway have been located using conventional survey methods. Inertial measurement unit (IMU) misalignment angles and horizontal accuracy are calculated by comparing the position of the building edges between opposing flight lines. The scanner scale factor and vertical accuracy is calculated through comparison of lidar data against control points along the runway. Field calibration is performed on all flight lines to refine the IMU misalignment angles. IMU misalignment angles are calculated from the relative displacement of features within the overlap region of adjacent (and opposing) flight lines. The raw lidar data is reduced using the refined misalignment angles.2015 NCTCOG Program Lidar Acquisition201501061200Woolpert, Inc.Geospatial Servicesmailing and physical address
4454 Idea Center Blvd.
DaytonOH45430USA(937) 461-5660(937) 461-07438:00 a.m. to 5:00 p.m. Eastern TimeGround control and QAQC control point survey for the 2015 NCTCOG Program was performed by Gorrondona & Associates surveyors, to support the 2015 NCTCOG Program 0.5m NPS Lidar project. All surveys were performed in such a way as to provide a reliable assessment of the LiDAR surface model. These points are carefully planned and selected within and equally distributed over the LiDAR project area. They are located in open terrain, where there is a high probability that the sensor will have detected the ground surface, without influence from the surrounding vegetation. The checkpoint accuracy shall satisfy a Local Network accuracy of 5-centimeters at the 95% confidence level.
All horizontal GPS control used for this project was based on the Texas State Plane Coordinate System, North Central Zone, NAD-83, expressed in US surveyfeet. The vertical control shall be based on the North American Vertical Datum of 1988 (NAVD 88).2015 NCTCOG Program Lidar ground control and QAQC control Acquisition201501131200Gorrondona & Associates, Inc.Geospatial Servicesmailing and physical address
4201 West Parmer Lane B-100
AustinTX78727USA(512) 719-9933(512) 719-99448:00 a.m. to 5:00 p.m. Eastern TimeThe individual flight lines were inspected to ensure the systematic and residual errors have been identified and removed. Then, the flight lines were compared to adjacent flight lines for any mismatches to obtain a homogenous coverage throughout the project area. The point cloud underwent a classification process to determine bare-earth points and non-ground points utilizing "first and only" as well as "last of many" lidar returns. This process determined Default (Class 1), Ground (Class 2), Low Vegetation (Class 3), Medium Vegetation (Class 4), High Vegetation (Class 5), Building (Class 6), Noise (Class 7), Water (Class 9), Overlap Default (Class 17) and Overlap Ground (Class 18). The bare-earth (Class 2 - Ground) lidar points underwent a manual QA/QC step to verify the quality of the DEM as well as a peer-based QC review. This included a review of the DEM surface to remove artifacts and ensure topographic quality. Classification of water (class 9) was completed via the use of the hydrologic breaklines collected for the hydro-flattening phase. The overlap classes were determined by first identifying the overlapping areas and reclassifying the LAS data by offset from a corridor. This allows the returns located on the edge of the swath to be removed from the bare earth coverage in an effort to produce a more uniform data density. The returns determined to be overlap are then further classified to produce overlap default (class 17) and overlap ground (class 18). The surveyed ground control points are used to make vertical adjustments to the data set and to perform the accuracy checks and statistical analysis of the lidar dataset. Supervisory QC monitoring of work in progress and completed editing ensured consistency of classification character and adherence to project requirements across the entire project area. The resulting deliverables for this task order consist of classified LAS file in LAS 1.2 format, Raw Swath LAS files in LAS 1.2 format, two (2) feet pixel size DEM files in ERDAS IMG format, two (2) feet pixel raster DSMs in ERDAS IMG Format, two (2) feet pixel size 8-bit Intensity files in GeoTIFF format, classified XYZ and Hydrologic Breakline data in ESRI shape file format.2015 NCTCOG Program Lidar Deliverable Processing20150107 1200Woolpert, Inc.Geospatial Servicesmailing and physical address
4454 Idea Center Blvd.
DaytonOH45430USA(937) 461-5660(937) 461-07438:00 a.m. to 5:00 p.m. Eastern TimePointNAD 1983 StatePlane Texas North Central FIPS 4202 Feet32.1333333333333333.96666666666667-98.531.666666666666671968500.06561666.666666666coordinate pair0.0000000278391087960017130.000000027839108796001713foot_usD North American 1983GRS 19806378137.0298.257222101North American Vertical Datum of 1988(GEOID09)0.000100metersExplicit elevation coordinate included with horizontal coordinatesNorth Central Texas Council of Governmentsmailing and physical address
616 Six Flags Dr.
ArlingtonTX76011USA(817) 695-9156Unknown8:00 a.m. to 5:00 p.m. Central TimeDownloadable DataWoolpert prepared the original data as set forth in the Scope of Services, in accordance with reasonable care and due diligence as set forth in this Agreement, however, due to the easily alterable nature of electronic media, files, documents, and other deliverables, Woolpert, Inc. makes no warranties, either expressed or implied, with respect to the accuracy, completeness, merchantability, or fitness for any particular purpose, including, but not limited to, use of any/all data as described within this metadata file, by any user of this data. Any use will be at the end-user’s sole risk.unknown20150528Woolpertmailing and physical address
4454 Idea Center Blvd.
DaytonOH45430USA(937) 461-5660(937) 461-0743 8:00 a.m. to 5:00 p.m. Eastern TimeFGDC Content Standards for Digital Geospatial MetadataFGDC-STD-001-1998local timeUnclassifiedUnclassifiedUnclassified