Data Management Plan (Deprecated)

Mississippi Coastal QL2 Lidar with 3DEP Extension Lidar 0.7m NPS Lidar Data Acquisition and Processing Production Task USGS Contract No.

G10PC00057

Task Order No. G15PD00091

Woolpert Order No. 75157

CONTRACTOR: Woolpert, Inc.

This task is for a high resolution data set of lidar covering approximately 5981 square miles. The lidar data was acquired and processed in compliance to U.S. Geological Survey National Geospatial Program Lidar Base Specification version 1.2. The lidar data was 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 0.7 meters. The final products include classified LAS, one (1) meter pixel raster DEMs of the bare-earth surface in ERDAS IMG Format, and 8-bit intensity images. Gridded products conform to a 1500 m x 1500 m tiling scheme. Each LAS file contains lidar point information, which has been calibrated, controlled, and classified. Additional deliverables include hydrologic breakline data, control data, flight line vectors and tile index provided as ESRI shapefile, lidar processing and survey reports in PDF format, FGDC metadata files for each data deliverable in .xml format, and LAS swath data. Ground conditions: Water at normal levels; no unusual inundation; no snow; leaf off.

In addition to the lidar point data, bare earth Digital Elevation Models (DEMs), at a 1 m grid spacing, created from the lidar point data are also available. These data are available for download here: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=6307 Breaklines created from the lidar area also available for download in either gdb or gpkg format at: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/6306/breaklines The DEM and breakline products have not been reviewed by the NOAA Office for Coastal Management (OCM) and any conclusions drawn from the analysis of this information are not the responsibility of NOAA, OCM or its partners.

Original contact information:

Contact Org: Woolpert

Phone: (937) 461-5660

Process Steps:

• 2015-01-28 00:00:00 - Lidar Acquisition Using two Leica ALS70 (lidar) systems on board a Woolpert aircraft, high density data, at a nominal pulse spacing (NPS) of 0.7 meters, were collected for this task order (approximately 5981 square miles). Leica Specs- AGL = 1,981 meters - Aircraft Speed = 150 Knots, Field of View (Full) = 40 degrees, Pulse Rate = 272 kHz, Scan Rate = 41.0 Hz, with an average side lap of 20%. Multiple returns were recorded for each laser pulse along with an intensity value for each return. Thirty-one (31) missions were flown between January 28, 2015 and April 01, 2015. Six (6) 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. Data for the task order is referenced to the UTM Zone 15N, North American Datum of 1983 (2011), and NAVD88, in meters. The geoid used to reduce satellite derived elevations to orthometric heights was GEOID12B. 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
• 2015-02-17 00:00:00 - Lidar Ground Control and QAQC control Acquisition The field crew utilized Real-Time Kinematic (RTK) GPS surveying throughout most of the ground control data collection process. Using RTK GPS techniques, observations were performed on a total of 89 LiDAR control points and 470 ground control quality check points. The survey was conducted using a 1-second epoch rate, in a fixed solution RTK mode, with each observation lasting between 60 to 180 seconds. Each station was occupied twice to insure the necessary horizontal and vertical accuracies were being met for this photogrammetric project.
• 2015-01-28 00:00:00 - Lidar Deliverable Processing The 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 homogeneous 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 Noise (Class 7), Water (Class 9), Ignored Ground (Class 10), Bridge Decks (Class 17) and High Noise (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) and ignored ground (class 10) 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 including overlap default, ground, water, and ignored ground are then applied an overlap flag and reclassified to their respective standard classification value. 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 1.4 format, Raw Swath LAS files in LAS 1.4 format, 1 meter pixel size DEM files in ERDAS IMG format, 1 meter pixel size 8-bit Intensity files in GeoTIFF format, and Hydrologic Breakline data in ESRI shape file format.
• 2017-05-24 00:00:00 - The NOAA Office for Coastal Management (OCM) received 2945 files in las 1.4 format. The files contained lidar intensity and elevation measurements for the 3DEP Co-Op project area. The data were in UTM 15 and UTM 16 (NAD83 2011) coordinates and in NAVD88 elevations in meters. OCM performed the following processing on the data for Digital Coast storage and provisioning purposes: 1. The LAStools software scripts lasinfo and lasvalidate were run on the las files to check for errors. 2. Internal OCM scripts were run to convert the files from UTM Zone 15 and 16 coordinates to geographic coordinates and to convert from NAVD88 elevations to ellipsoid elevations using Geoid12B. 3. Internal OCM scripts were run on the las files to assign the geokeys, to sort the data by gps time and zip the data to database and to http.

This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=6306;