2012 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Hoh River Watershed, Washington
This kmz file shows the extent of coverage for the 2012 PSLC Hoh River Watershed lidar
Watershed Sciences, Inc. (WSI) collected Light Detection and Ranging (LiDAR) data
on the Hoh River watershed survey area for the Puget Sound LiDAR Consortium and the
Hoh Tribe Department of Natural Resources. This data set covers approximately 181
square miles. Due to spring snow on the ground WSI was unable to acquire data for
the complete survey during the initial flights in April and will return to finish
acquisition at a later date. Delivery 1 of the survey area was collected on April
14th, 15th, 17th, 19th, 20th and 21st. 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 =60% (=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 acheived a nominal point spacing of 8.4
points per square meter.
Cite this dataset when used as a source.
|Search and Download
|| Distributor information not available
| Point of Contact
Puget Sound Lidar Consortium (PSLC)
Lidar Dataset Supplemental Information
- Diana Martinez
Puget Sound Lidar Consortium (PSLC)
- Hoh Tribe Department of Natural Resources
|Data Presentation Form:
|| Digital image
|Dataset Progress Status
|Data Update Frequency:
|| As needed
||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.
||2012-04-14 to 2012-04-21
|Spatial Reference System:
|Spatial Bounding Box Coordinates:
|Spatial Coverage Map:
- Remote Sensing
- Jefferson County
- Hoh River
| Use Constraints
|| No constraint information available
|| Fee information not available.
|| Lineage statement not available.
| 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
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, Corpscon 6 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.
Position and attitude data were imported. 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. 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.
Software: TerraScan v.12.004, ArcMap v.10.0, TerraModeler v.12.002 8. Intensity images
were created as Geo TIFFs and mosaicked to the final delineation. 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 las files were converted from
orthometric (NAVD88) heights to ellipsoidal heights using Geoid03. 2. The topographic
las files were converted from a Projected Coordinate System (WA SP South) to a Geographic
Coordinate system (NAD83). 3. The topographic las files' vertical units were converted
from feet to meters. 4. The topographic las 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
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
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
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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