Data Management Plan

These files contain rasterized bare earth bathymetric and topographic lidar elevations generated from data collected by the SHOALS-1000T and RIEGL VQ-480 sensor, respectively. These sensors were flown concurrently with a digital camera and hyperspectral imager on a single remote sensing platform for use in coastal mapping and charting activities. The 3-D position data are used to generate a series of gridded file products, with each covering approximately 5 kilometers of shoreline. These bare earth Digital Elevation Models (DEMs)are at a 1 meter grid spacing. In addition to the bare earth DEMs, the topobathy lidar point data are also available. These data are available for download here: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=4912 DEMs that were created from all classes of points (1, 2, 29) at a 1 meter grid size are available by request via email at: coastal.info@noaa.gov.

Original contact information:

Contact Org: JALBTCX

Title: Data Production Manager

Phone: 228-252-1121

Email: JALBTCX@usace.army.mil

Process Steps:

• 2014-09-08 00:00:00 - The topographic lidar data were collected using the RIEGL VQ-480 lidar system, operated by Fugro Pelagos through contract. The system collects topographic lidar data at maximum pulse rate of 200 kHz in a near-infrared wavelength producing point cloud density between 2.5-2.8 pts/sq m. Aircraft position, velocity and acceleration information are collected a Applanix POS AV 510 sensor. All logged raw data were transferred to the office and processed in RIEGL RiPROCESS software v1.6.1. Aircraft position data are processed using Applanix POSPac MMS v6.2.2 software and the results combined with the lidar data to produce 3-D positions for each lidar shot. 3D point clouds are inspected in RiProcess software and scan adjustments performed after careful scrutiny. The 200% redundant coverage achieved with the VQ-480 flight plan helped in the data validation efforts by removing scan lines that presented excessive mismatch and misalignments. Upon processing and export to LAS format, QA/QC is performed with QPS Fledermaus v7.3.3 software. These bathymetric lidar data were collected using the SHOALS-1000T bathymetric lidar system. It is owned by Fugro Pelagos Inc. and operated through contract. The system collects bathymetric lidar data at 2.5 kHz and RGB imagery at 1 Hz, producing point clouds with an approximate spot spacing of 4.0-5.0 m x 2.5 m. Aircraft position, velocity and acceleration information are collected through a POS AV 510 sensor. All logged raw data streams are transferred to the office for downloading and processing in SHOALS GCS v 6.32 software. Aircraft position data are processed using Applanix POSPac MMS v 6.2.2 software and the results combined with the sensor data to produce 3-D positions for each lidar shot on the NAD83(2011) reference datum. Upon inspection and QA/QC in the software package Fledermaus v7.3.3, anomalous data are flagged as invalid; a percentage of data are also re-processed after further refinement of parameters to account for system-related biases. The data files also contain topographic coverage of adjacent terrain (land elevations). Upon inspection at JALBTCX, utilizing the QA/QC software packages Fledermaus and PFM_ABE, any additional anomalous data are flagged as invalid. PFM_ABE software then exports all bathymetric lidar data as a series of unclassified LAS files.
• 2016-02-02 00:00:00 - LAS files are imported into GeoCue V2014.1.21.4, which is a geospatial workflow production and management software tool employed by JALBTCX to perform and monitor production of data products. Upon import into GeoCue, A customized classification macro, built upon the TerraScan V13 module within Microstation V8i, classifies valid topobathy data as ground points (2), unclassified points (1), and bathymetric points (29). Upon completion the macro, the classification results undergo quality control and any misclassified points are manually edited. In areas of dense vegetation the bare earth ground points might be incorrectly classified due to the inability of the laser to penetrate the canopy and reach the bare ground. In these areas, JALBTCX defaults to the algorithm's "ground" surface instead of manually reclassifying those points. They are partitioned into a series of 5km or quarter quad delivery boxes, one Classified LAS file per box. The format of the file is LAS version 1.2. Data are classified as 1 (valid non-ground topographic data), 2 (valid ground topographic data), and 29 (valid bathymetric data). The National Geodetic Survey's (NGS) GEOID12B model is used to transform the vertical positions from ellipsoid to orthometric heights referenced to the North American Vertical Datum of 1988 (NAVD88).
• 2016-03-10 00:00:00 - Data classified as ground points (2) and bathymetric points (29) in the las files are converted to a grid by generating a triangulated irregular network (TIN) and then extracting the grid node elevations from the TIN surface. The origin point of the grid is located at a horizontal position whose value is evenly divisible by the 1m grid resolution such that rasters from subsequent surveys have common cell boundaries. JALBTCX uses Quick Terrain Modeler V8 to perform this operation utilizing the following parameters; "Legacy Triangulation", "Max Sample Excursion - 50", "Max Triangle Side - 100", "Radius - none", "Tolerance - 1", and "Tiling Settings Snap to Grid (Expand)." The grid is exported from Quick Terrain Modeler as an ESRI ASCII Z grid file. Utilizing an in-house python script within ESRI ArcMap V10.2, the ASCII Z grid file is converted to a tiff-format raster file whose projection is defined as "The North American Datum of 1983 (2011)." The raster is then multiplied against a corresponding 1m Grid mask raster, a mask image produced from JALBTCX's 1m Grid, in ESRI's Raster Calculator to remove interpolated areas where data does not exist.
• 2016-11-22 00:00:00 - The NOAA Office for Coastal Management (OCM) received data in tif format from JALBTCX. The bare earth raster files were at a 1 m grid spacing. The data were in geographic coordinates and NAVD88 elevations in meters. OCM copied the raster files to database and ftp for Digital Coast storage and provisioning purposes.

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

https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=5189

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