2012 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Upper Naches River, Washington

Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data of the Upper Naches River Valley and Nile Slide area of interest on

September 30th, 2011-October 1st, 2011 and April 5th, 2012 for the Puget Sound LiDAR Consortium. The valley bottom was reflown in 2012 during "leaf-off"

conditions, to ensure a more detailed bare earth model, and matched with the upslope data from 2011 to provide a seamless dataset. The requested area was

expanded to include a 100m buffer to ensure complete coverage and adequate point densities around survey area boundaries. The total acreage of this

delivery is 23,771 acres of LiDAR data.

The LiDAR survey utilized 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 11.60 points per square meter.

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.

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A footprint of this data set may be viewed in Google Earth at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/2511/supplemental/wa2012_pslc_uppernaches_footprint.KMZ

A Lidar Report from the vendor for this data set may be viewed here:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/2511/supplemental/wa2012_pslc_uppernaches_lidarreport.pdf

LiDAR points in LAZ format

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Any conclusions drawn from the analysis of this information are not the responsibility

of Watershed Sciences Inc., PSLC, NOAA, the Office for Coastal Management or its partners.

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

https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=2511

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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and some parts of this data may no longer represent actual surface conditions.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. These data

depict the heights at the time of the survey and are only accurate for that time.

Elevations are recorded in floating-point meters and the vertical datum is ellipsoidal (GEOID03). There are no other attribute tables.

Not applicable for pure elevation data: every XY error has an associated Z error.

See the "Project Report" above for a detailed accuracy report.; Quantitative Value: 0.0236 meters, Test that produced the value:

Root mean square Z error in open, near-horizontal areas, as specified by contract. Units in meters. Accuracy may be significantly less in steep

areas and under heavy forest canopy.

Elevation data has been collected for all areas inside project boundaries. The data set was flown with a 60% sidelap between flightlines and a 100

meter buffer to ensure all areas are properly sampled.

Puget Sound Lidar Consortium evaluates logical consistency of high-resolution lidar elevation data with three tests: examination of file names,

file formats, and mean and extreme values within each file; internal consistency of measured Z values in areas where survey swaths overlap;

and visual inspection of shaded-relief images calculated from bare-earth models.

File names, formats, and values: All file naming convention and file formats are checked for consistency.

Visual inspection of bare earth surfaces were examined to find any obvious data errors such as blunders, border artifacts, gaps between data quads,

no-data gaps between flight lines, hillscarps, land shifting due to GPS time errors, etc.