2014 Lidar: St. Charles Parish, LA

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This graphic shows the lidar footprint for the 2014 St. Charles Parish, LA project.

Date that the source FGDC record was last modified.

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.

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Airborne Lidar and processing to seamless tiles | Source Geospatial Form: vector digital data | Type of Source Media: digital data files

All products were reviewed and approved by ASPRS Certified Photogrammetrist, Ken Comeaux.

DATA ACQUISITION: - Ground Control Survey: All lidar control and check points were collected by Precision Aerial Reconnaissance field crews by means of Real time VRS with a Trimble R10 receiver with internal antennas and using a TSC3 data collector. Trimble Business Center (TBC) software was used to process collected field data against a network of established NGS control. Each control or check point was occupied for a duration of at least 3 minutes. LiDAR check points were collected in the following ground classification categories: Bare Ground, Marsh, Tall Grass and Urban. In addition, a sampling of vertical LiDAR control points was collected in areas of Bare Ground. The LiDAR check and control points were also collected using VRS-RTK techniques. - LiDAR Acquisition: The LiDAR data was collected using a Leica ALS70CM sensor between 15-Feb-2014 and 30-Mar-2014 at an altitude of 4,500 feet AMT with a planned average point density of 9.1 points per square meter to support the generation of 2' contours meeting FEMA specifications for Aerial Mapping and Surveying to Support 2-foot contours. The LiDAR collection was supported by ground base stations.

LIDAR PROCESSING: - LiDAR Calibration: Initial processing of the GPS and IMU data was performed using Leica IPAS TC. The SOL was generated and Leica ALS Post Processor software was used to generate georeferenced laser returns which were then processed in strip form allowing for the QC of the overlap between strips (lines). The data from each line were combined and automated classification routines run to determine the initial surface model. This initial surface model was then verified to the LiDAR test points. - LiDAR Classification: The calibrated LiDAR data was run through automated classification routines and then manually checked. The data was classified into the following classes: Unclassified (1), Ground (2), Medium Vegetation (4), Low point and noise (7), Water (9) and Overlap (12).

The NOAA Office for Coastal Management (OCM) received 770 files in las 1.2 format. The files contained lidar intensity and elevation measurements for the St. Charles Parish, LA project area. The data were in LA State Plane, Zone 1702 (NAD83 2011) coordinates and in NAVD88 elevations in feet. 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 LA State Plane Zone 1702 coordinates to geographic coordinates and to convert from NAVD88 elevations in feet to ellipsoid elevations in meters, using Geoid12A.

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.