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2012 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Chehalis River Watershed Area, Washington

browse graphicThis kmz file shows the extent of coverage for the 2012 PSLC Chehalis River Watershed lidar data set.
Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data for the Chehalis River Watershed study area on January 28th, February 2nd-7th, March 4th-9th, March 21st-23rd, and April 7th, 2012. Acquisition days were not consecutive due to weather. Data was collected for the Puget Sound LiDAR Consortium in partnership with the Federal Emergency Management Agency Region X (FEMA), Washington Department of Natural Resources, and Lewis County. The requested area of 224,713 acres for the Chehalis River Watershed was expanded to include a 100m buffer to ensure complete coverage and adequate point densities around survey area boundaries resulting in a total of 234,556 acres of delivered LiDAR data. The LiDAR survey utilized an Optech Orion-C and a Leica ALS60 sensor in a Cessna Caravan 208B. Please see "Project Report" below for specific information regarding the airborne survey and ground survey. This Lidar survey acheived a nominal point spacing of 10.94 points per square meter.

Cite this dataset when used as a source.

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    Distribution Formats
    • LAZ
    Distributor DOC/NOAA/NOS/CSC > Coastal Services Center, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Point of Contact Diana Martinez
    Puget Sound Lidar Consortium (PSLC)
    206-971-3052
    dmartinez@psrc.org
    Associated Resources
    • Lidar Dataset Supplemental Information
    Originator
    • DOC/NOAA/NOS/CSC > Coastal Services Center, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Originator
    • Diana Martinez
      Puget Sound Lidar Consortium (PSLC)
    Originator
    • DHS/FEMA > Federal Emergency Management Agency, U.S. Department of Homeland Security
    Originator
    • Washington Department of Natural Resources
    Originator
    • Lewis County, WA
    Publisher
    • DOC/NOAA/NOS/CSC > Coastal Services Center, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Date(s)
    • publication: 2013-06-01
    Data Presentation Form: Digital image
    Dataset Progress Status Complete
    Data Update Frequency: As needed
    Purpose: The LAS files can be used to create DEMs and also to extract topographic data in software that does not support raster data. Other surface features can also be extracted with custom applications. LiDAR data has a wide range of uses such as earthquake hazard studies, hydrologic modeling, forestry, coastal engineering, roadway and pipeline engineering, flood plain mapping, wetland studies, geologic studies and a variety of analytical and cartographic projects.
    Use Limitations
    • These data depict the elevations at the time of the survey and are only accurate for that time. Users should be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations. Any conclusions drawn from analysis of this information are not the responsibility of NOAA or any of its partners. These data are NOT to be used for navigational purposes.
    Time Period: 2012-01-28  to  2012-04-07
    Spatial Reference System: urn:ogc:def:crs:EPSG::4269 Ellipsoid in Meters
    Spatial Bounding Box Coordinates:
    N: 47.058480
    S: 46.386544
    E: -122.749918
    W: -123.619278
    Spatial Coverage Map:
    Themes
    • Topography/Bathymetry
    • Elevation
    • Model
    • LiDAR
    • LAZ
    • Remote Sensing
    Places
    • US
    • Washington
    • Grays Harbor County
    • Lewis County
    • Chehalis River Watershed
    Use Constraints No constraint information available
    Fees Fee information not available.
    Lineage Statement Lineage statement not available.
    Processor
    • DOC/NOAA/NOS/CSC > Coastal Services Center, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
    Processing Steps
    • 1. Resolved kinematic corrections for aircraft position data using kinematic aircraft GPS and static ground GPS data. Software: Waypoint GPS v.8.10, Trimble Business Center v.2.6 2. Developed a smoothed best estimate of trajectory (SBET) file that blends post-processed aircraft position with attitude data. Sensor head position and attitude were calculated throughout the survey. The SBET data were used extensively for laser point processing. Software: IPAS TC v.3.1 3. Calculated laser point position by associating SBET position to each laser point return time, scan angle, intensity, etc. Created raw laser point cloud data for the entire survey in *.las (ASPRS v. 1.2) format. Data were then converted to orthometric elevations (NAVD88) by applying a Geoid03 correction. Software: ALS Post Processing Software v.2.74 4. Imported raw laser points into manageable blocks (less than 500 MB) to perform manual relative accuracy calibration and filter for pits/birds. Ground points were then classified for individual flight lines (to be used for relative accuracy testing and calibration). Software: TerraScan v.12.004 5. Using ground classified points per each flight line, the relative accuracy was tested. Automated line-to-line calibrations were then performed for system attitude parameters (pitch, roll, heading), mirror flex (scale) and GPS/IMU drift. Calibrations were performed on ground classified points from paired flight lines. Every flight line was used for relative accuracy calibration. Software: TerraMatch v.12.001 6. Resulting data were classified as ground and non-ground points. Statistical absolute accuracy was assessed via direct comparisons of ground classified points to ground RTK survey data. Software: TerraScan v.12.004, TerraModeler v.12.002 7. Final version of data was checked for duplicate points using TerraScan software. No duplicate points were found. Software: TerraScan v.12.004, TerraModeler v.12.002 8. Bare Earth models were created as a triangulated surface and exported as ArcInfo ASCII grids at a 3?foot pixel resolution. Highest Hit models were created for any class at 3-foot grid spacing and exported as ArcInfo ASCII grids. Hydroflattened Bare Earth models were created as a triangulated surface with breaklines enforced and exported as ArcInfo ASCII grids at a 3?foot pixel resolution. Software: TerraScan v.12.004, ArcMap v. 10.0, TerraModeler v.12.002
    • The NOAA Coastal Services Center (CSC) 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. CSC performed the following processing for data storage and Digital Coast provisioning purposes: 1. The topographic laz files were converted from orthometric (NAVD88) heights to ellipsoidal heights using Geoid03. 2. The topographic laz files were converted from a Projected Coordinate System (WA SP South) to a Geographic Coordinate system (NAD83). 3. The topographic laz files' vertical units were converted from feet to meters. 4. The topographic laz files' horizontal units were converted from feet to decimal degrees.
    • The NOAA National Geophysical Data Center (NGDC) received lidar data files via ftp transfer from the NOAA Coastal Services Center. The data are currently being served via NOAA CSC Digital Coast at http://www.csc.noaa.gov/digitalcoast/. The data can be used to re-populate the system. The data are archived in LAS or LAZ format. The LAS format is an industry standard for LiDAR data developed by the American Society of Photogrammetry and Remote Sensing (ASPRS); LAZ is a loseless compressed version of LAS developed by Martin Isenburg (http://www.laszip.org/). The data are exclusively in geographic coordinates (either NAD83 or ITRF94). The data are referenced vertically to the ellipsoid (either GRS80 or ITRF94), allowing for the ability to apply the most up to date geoid model when transforming to orthometric heights.

    Metadata Last Modified: 2013-06-28

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