Data Management Plan (Deprecated)

The dataset encompasses portions of Wenas Valley in Kitittas and Yakima Counties, Washington.

The bare earth digital elevation models (DEMs) 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. Some elevation values

have been interpolated across areas in the ground model where there is no elevation

data (e.g. over dense vegetation).

The DEM grid cell size is 3-ft. The projection is NAD83 (HARN) Washington State Plane,

South. The elevation units are in U.S. Survey Feet.

Watershed Sciences, Inc. collected the LiDAR and created this data set for the Puget

Sound LiDAR Consortium.

Watershed Sciences, Inc. (WS) initially collected 37,969 acres of Light Detection

and Ranging (LiDAR) data of the Wenas Valley area of interest (AOI) in Kittitas and Yakima

Counties, WA on October 28th, 2009. This data was delivered on November 21st, 2009.

After the AOI was clear of snow, the remaining 110,255 acres were collected on March

22nd and from June 12th to June 16th, 2010. The total deliverable area including a

100 m buffer is 148,224 acres.

Process Steps:

• Acquisition. The LiDAR data was collected on October 28th, 2009, March 22, 2010 and June 12th-16th, 2010. The survey used both the Leica ALS50 Pase II and ALS 60 laser systems 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.
• 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, and Waypoint GPS, 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
• 2013-11-18 00:00:00 - The NOAA Office for Coastal Management (OCM) downloaded topographic files in text format from PSLC's website. The files contained lidar easting, northing, elevation, intensity, return number, class, scan angle and GPS time measurements. The data were received in Washington State Plane South Zone 4601, 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. The All-Return ASCII txt files were parsed to LAS files. 2. The All-Return ASCII files were converted from txt format to las format using LASTools' txt2las tool and reclassified to fit the OCM class list, N=1 (unclassified), G=2 (ground). 3. The las files were converted from orthometric (NAVD88) heights to ellipsoidal heights using Geoid03. 4. The las files' vertical units were converted from feet to meters, removing bad elevations. 5. The las files were converted from a Projected Coordinate System (WA SP South) to a Geographic Coordinate system (NAD83) 6. The las files' horizontal units were converted from feet to decimal degrees and converted to laz format.

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

https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=2588

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