Data Management Plan

Watershed Sciences, Inc. (WS) collected Light Detection and Ranging (LiDAR) data for the Department of Geology and Mineral Industries (DOGAMI) and the Oregon Department of Forestry (ODF). The Areas of Interest (AOIs) cover portions of eight counties in northwest Oregon. The extent of requested LiDAR area totals ~1,549,015 acres; the extent of the LiDAR area delivered covers ~1,586,385 acres. The dataset encompasses portions of the following counties in northwest Oregon: Tillamook, Columbia, Multnomah, Washington, Marion, Yamhill, Hood River, and Clackamas.

The bare earth digital elevation models (DEM) represent the earth's surface with all vegetation and human-made structures removed. The bare earth DEMs were derived from LiDAR data using TIN processing of the ground point returns. The DEM grid cell size is 3 international feet. The elevation units are in U.S. survey feet. Some elevation values have been interpolated across areas in the ground model where there is no elevation data (e.g. over water, over dense vegetation).

The NOAA Office for Coastal Management (OCM) received 101 ADF DEM files from the Oregon Lidar Consortium. These files were processed to the Data Access Viewer (DAV) and https. In addition to bare earth digital elevation models, the lidar point data are available for download at the link in the Related Items section of this metadata record. Please note that these products have not been reviewed by OCM, and any conclusions drawn from the analysis of this information are not the responsibility of NOAA or OCM.

Process Steps:

• Acquisition. The LiDAR data was collected between March 15, 2007 and April 11, 2009. The survey used a Leica ALS50 Pase II laser system mounted in a Cessna Caravan 208, and an Optech 3100 laser system mounted in a Cessna Caravan 208. 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, IPAS Pro GPS/INS software, REALM survey suite, and PosPac 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 and REALM software tools, 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.
• 2009-06-16 00:00:00 - The NOAA Office for Coastal Management (OCM) received 101 ADF DEM files from the Oregon Lidar Comission. These files were converted to GeoTIFF format and EPSG codes assigned using gdaltranslate and internal scripts. The data was then processed to the Data Access Viewer (DAV) and https.

Data is available online for custom downloads