Data Management Plan

Sonoma County Vegetation Mapping and LiDAR Consortium retained WSI to provide lidar and Orthophoto data and derived products in Sonoma County, CA. A classified LAS format point cloud was collected and developed. Products, such as bare earth DEMs, were derived from the lidar, but are not covered here. The original specified coordinate system for this dataset is California State Plane Zone II (FIPS 0402), NAD83 (2011), with units in US Survey Feet for horizontal, and vertical units are NAVD88 (12A) US Survey Feet. It was converted to geographic coordinates and ellipsoid heights for customized distribution through the Digital Coast. The dataset encompasses Sonoma County. The Bare earth DEMs are also available. These products have not been reviewed by the NOAA Office for Coastal Management (OCM) and any conclusions drawn from the analysis of this information are not the responsibility of NOAA, OCM or its partners. The data are available upon request via email at: coastal.info@noaa.gov.

Process Steps:

• 2014-01-24 00:00:00 - Acquisition. Lidar data acquisition was started September 28, 2013 and was completed on November 26, 2013. The survey is utilizing a Leica ALS50 or ALS70 laser system mounted in a Piper Navajo PA-31-325 or Cessna Caravan 208B. 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.
• 2014-01-24 00:00:00 - Lidar Data Processing. Flight lines and data were reviewed to ensure complete coverage of the study area and positional accuracy of the laser points. 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. The raw lidar file was assembled into flight lines per return with each point having an associated x, y, and z coordinate. Visual inspection of swath to swath laser point consistencies within the study area were used to perform manual refinements of system alignment. 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. Noise (e.g., pits and birds) was filtered using ALS post-processing software, based on known elevation ranges and included the removal of any cycle slips. Using TerraScan and MicroStation, ground classifications utilized custom settings appropriate to the study area. The corrected and filtered return points were compared to the RTK ground survey points collected to verify the vertical and horizontal accuracies.
• 2014-05-13 00:00:00 - The lidar files were received by the NOAA Office for Coastal Management for incorporation into the NOAA Digital Coast from the Sonoma County Agricultural Preservation and Open Space District. The data consisted of 11035 lidar files in LAZ format. The data were in NAD 1983 (2011) State Plane California FIPS 0402 coordinates horizontally and NAVD88 (GEOID12a) feet vertically. The classifications of the data were: 1 (Unclassified), 2 (Ground), 5 (vegetation), 6 (building), 7 (Noise), and 9 (Water). For Digital Coast data storage and provisioning purposes, the NOAA Office of Coastal Management performed the following processing: 1) The data were reviewed for any elevation outliers; 2) The data were converted from State Plane coordinates to geographic coordinates; 3) The data were converted from NAVD88 elevations to ellipsoid elevations using Geoid12a; 4) File names were changed to incorporate the date of the first point in the file and the area designation. 5) 5 replacement files were processed on 4/18/2016. (Citation: Processed lidar point clouds)