2012 Oregon Lidar Consortium (OLC) Lidar DEM: Keno (OR)

Create custom data files by choosing data area, product type, map projection, file format, datum, etc.

Simple download of data files.

Custom download facility for the point cloud data that was used to make this DEM.

Data report from the lidar vendor.

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.

Partial upload of Positional Accuracy fields only.

Partial upload to move data access links to Distribution Info.

Acquisition.

LiDAR data acquisition began May 19, 2012 and was completed August 16, 2012. The survey utilized Leica ALS50 Phase II and ALS60 laser systems mounted in a Cessna Caravan 208B and Partenavia P.38. Near nadir scan angles were used to increase penetration of vegetation to ground surfaces. Ground level GPS and aircraft IMU were collected during the flight.

Processing.

1. Flight lines and data were reviewed to ensure complete coverage of the study area and positional accuracy of the laser points.

2. Laser point return coordinates were computed using ALS Post Processor software and IPAS Pro GPS/INS software, based on independent data from the LiDAR system, IMU, and aircraft.

3. The raw LiDAR file was assembled into flight lines per return with each point having an associated x, y, and z coordinate.

4. Visual inspection of swath to swath laser point consistencies within the study area were used to perform manual refinements of system alignment.

5. Custom algorithms were designed to evaluate points between adjacent flight lines. Automated system alignment was computed based upon randomly selected swath to swath accuracy measurements that consider elevation, slope, and intensities. Specifically, refinement in the combination of system pitch, roll and yaw offset parameters optimize internal consistency.

6. Noise (e.g., pits and birds) was filtered using ALS postprocessing software, based on known elevation ranges and included the removal of any cycle slips.

7. Using TerraScan and Microstation, ground classifications utilized custom settings appropriate to the study area.

8. The corrected and filtered return points were compared to the RTK ground survey points collected to verify the vertical and horizontal accuracies.

9. Points were output as laser points, TINed and GRIDed surfaces.

The NOAA Office for Coastal Management (OCM) received the files in the proprietary ESRI grid format from the Oregon Lidar Consortium. The data were in Oregon Lambert (NAD83 HARN), International Feet coordinates and NAVD88 (Geoid03) vertical feet. OCM performed the following processing to the data to make it available in the Digital Coast:

1. The files were converted from ESRI Grid format to floating point GeoTiff format

2. The vertical units of the data were converted from International feet to meters using gdal_translate from GDAL version 2.1.1..

Files were converted to cloud optimized geotiff format to support streaming and the vertical units were reverted to feet to match the horizontal units.