Data Management Plan

Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data for the Lewis County survey area

for the Puget Sound LiDAR Consortium. This data set covers approximately 547 square miles. Delivery 1 of the survey

area was collected on July 18th, 19th and 20th of 2009.

The LiDAR survey utilized both a Leica ALS60 and a Leica ALS50-II sensor in a Cessna Caravan 208B. All areas were

surveyed with an opposing flight line side-lap of 50% (=100% overlap) to reduce laser shadowing and increase

surface laser painting. The Leica laser systems allow up to four range measurements (returns) per pulse,

and all discernible laser returns were processed for the output dataset.

This LiDAR survey achieved a nominal point spacing of 8.82 points per square meter.

Original contact information:

Contact Org: Puget Sound LiDAR Consortium / Puget Sound Regional Council

Phone: 206-464-5325

Process Steps:

• 2009-12-10 00:00:00 - 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 the IPAS survey suite and ALS Post Processing 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 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 broken into processing bins and output areas and output as laser points, TINed and GRIDed surfaces. Bare earth DEMs meet PSLC specification.
• 2013-08-01 00:00:00 - The NOAA Office for Coastal Management (OCM) downloaded topographic files in .LAZ format from PSLC's website. The files contained LiDAR elevation and intensity measurements. The data were received in Washington State Plane South Zone 4602, NAD83 coordinates and were vertically referenced to NAVD88 using the Geoid03 model. The vertical units of the data were feet. OCM performed the following processing for data storage and Digital Coast provisioning purposes: 1. ASCII xyz files were parsed to LAS files. 2. The topographic LAS files were converted from orthometric (NAVD88) heights to ellipsoidal heights using Geoid03. 3. The topographic LAS files were converted from a Projected Coordinate System (WA SP South) to a Geographic Coordinate system (NAD83). 4. The topographic LAS files' vertical units were converted from feet to meters. 5. The topographic LAS files' were converted from NAVD88 (orthometric) heights to GRS80 (ellipsoid) heights using Geoid03. 6. The topographic LAS files were geotagged and header information was updated.

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

https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=2520

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