Data Management Plan

This report contains a comprehensive outline of the Mississippi QL2 and Tupelo QL3 Lidar Processing task order for the United States Geological Survey (USGS). This task is issued under USGS Contract No. G10PC00057, Task Order No. G14PD01046. This task order requires lidar data to be acquired over approximately 4385 square miles. The lidar was collected and processed to meet a maximum Nominal Post Spacing (NPS) of 0.7 meter. The NPS assessment is made against single swath, first return data located within the geometrically usable center portion (typically ~90%) of each swath.

Process Steps:

• USGS Contract No. G10PC00057. Task Order No. G12PD000125. Woolpert Order No. 073054
• 2015-01-31 00:00:00 - USGS Contract No. G10PC00057, Task Order No. G14PD01046
• 2012-01-01 00:00:00 - 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.
• 2015-02-03 00:00:00 - 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.
• 2015-12-01 00:00:00 - When the sensor calibration, data acquisition, and GPS processing phases were complete, the formal data reduction processes by Woolpert lidar specialists included: - Processed individual flight lines to derive a raw "Point Cloud" LAS file. Matched overlapping flight lines, generated statistics for evaluation comparisons, and made the necessary adjustments to remove any residual systematic error. - Calibrated LAS files were imported into the task order tiles and initially filtered to create a ground and non-ground class. Then additional classes were filtered as necessary to meet client specified classes. - Once all project data was imported and classified, survey ground control data was imported and calculated for an accuracy assessment. As a QC measure, Woolpert has developed a routine to generate accuracy statistical reports by comparisons against the TIN and the DEM using surveyed ground control of higher accuracy. The lidar is adjusted accordingly to meet or exceed the vertical accuracy requirements. - The lidar tiles were reviewed using a series of proprietary QA/QC procedures to ensure it fulfills the task order requirements. A portion of this requires a manual step to ensure anomalies have been removed from the ground class. - The lidar LAS files are classified into the Default (Class 1), Ground (Class 2), Low Noise (Class 7), Water (Class 9), Ignored Ground (Class 10), Overlap Default (Class 17) and Overlap Ground (Class 18) classifications. - FGDC Compliant metadata was developed for the task order in .xml format for the final data products. - The horizontal datum used for the task order was referenced to UTM16N North American Datum of 1983 (2011) and UTM15N North American Datum of 1983 (2011). The vertical datum used for the task order was referenced to NAVD 1988, meters, GEOID12A. Coordinate positions were specified in units of meters.
• 2016-09-20 00:00:00 - The NOAA Office for Coastal Management (coast) received the LAS files in from MARIS (Mississippi Automated Resource Information System) via an FTP site. The data was received in UTM zones 15 and 16 horizontal coordinates in meters with vertical coordinates referenced to NAVD88 in meters. The Digital Coast performed the following processing for data storage and Digital Coast provisioning purposes: 1. The LAS files had all overlap and duplicate tiles removed. This was due to the separation of tiles into counties which created a number of duplicate tiles altogether then converted to LAZ format. 2. UTM 15 LAZ tiles were transformed to UTM 16 coordinates in order to remove overlap between the UTM zones. 3. The vertical coordinates were reprojected to ellipsoidal heights using Geoid12a and horizontal coordinates were reprojected to geographic decimal degrees.

This data can be obtained on-line at the following URL:

https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=4907;