2013 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: Tulalip Partnership
This kmz file shows the extent of coverage for the 2013 PSLC Tulialip Partnership
lidar data set.
In October 2012, WSI (Watershed Sciences, Inc.) was contracted by the Puget Sound
LiDAR Consortium (PSLC)to collect Light Detection and Ranging (LiDAR) data on a 5-year
cycle for sites in Washington. The Tulalipsite in northwestern Washington is one of
these sites. Unclassified (1), Ground (2) and Snow (14).
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)
|Data Presentation Form:
|| Digital image
|Dataset Progress Status
|Data Update Frequency:
|| As needed
||Provide high resolution terrain elevation and land cover elevation data. Data were
collected to aidin assessing stream and forest habitat.
||2013-07-03 2013-07-06 2013-07-12 2013-07-19 2013-07-23 to 2013-07-04 2013-07-09 2013-07-16 2013-07-21 2013-07-31
|Spatial Reference System:
|Spatial Bounding Box Coordinates:
|Spatial Coverage Map:
- Remote Sensing
- Snohomish County
- Skagit County
| Use Constraints
|| No constraint information available
|| Fee information not available.
|| Lineage statement not available.
| Processing Steps
- Planning.In preparation for data collection, WSI reviewed the project area using Google
Earth,and flightlines were developed using a combination of specialized software.
Carefulplanning by acquisition staff entailed adapting the pulse rate, flight altitude,
scanangle, and ground speed to ensure complete coverage of the study area at thetarget
point density of 11.43 points per square meter (ground points only were calculated
at0.83 points per square meter). Efforts are taken to optimize flight paths by minimizingflight
times while meeting all accuracy specifications.Factors such as satellite constellation
availability and weather windows mustbe considered during the planning stage. Any
weather hazards or conditions affectingthe flight were continuously monitored due
to their potential impact on the dailysuccess of airborne and ground operations. In
addition, a variety of logisticalconsiderations required review including private
property access, potential airspace restrictions, and availability of company resources
(both staff andequipment).Special care was taken to acquire the tidal flats at low
- LiDAR Processing Steps:1. Resolve kinematic corrections for aircraft position data
using kinematic aircraft GPSand static ground GPS data.Software - Waypoint GPS v.8.3
Trimble Business Center v.3.00 Geographic Calculator 20132. Develop a smoothed best
estimate of trajectory (SBET) file that blends post-processedaircraft position with
attitude data. Sensor head position and attitude are calculatedthroughout the survey.
The SBET data are used extensively for laser point processing.Software - IPAS TC v.3.13.
Calculate laser point position by associating SBET position to each laser point returntime,
scan angle, intensity, etc. Create raw laser point cloud data for the entire surveyin
*.las (ASPRS v. 1.2) format. Data are converted to orthometric elevations (NAVD88)
byapplying a Geoid12 correction.Software - ALS Post Processing Software v.2.744. Import
raw laser points into manageable blocks (less than 500 MB) to perform manualrelative
accuracy calibration and filter erroneous points. Ground points are thenclassified
for individual flight lines (to be used for relative accuracy testingand calibration).Software
- TerraScan v.13.0085. Using ground classified points per each flight line, the relative
accuracy is tested.Automated line-to-line calibrations are then performed for system
attitude parameters(pitch, roll, heading), mirror flex (scale) and GPS/IMU drift.Calibrations
are calculated on ground classified points from paired flight lines andresults are
applied to all points in a flight line. Every flight line is used forrelative accuracy
calibration.Software - TerraMatch v.13.0026. Classify resulting data to ground and
other client designated ASPRSclassifications (Table 7). Assess statistical absolute
accuracy via direct comparisonsof ground classified points to ground RTK survey data.Software
- TerraScan v.13.008 TerraModeler v.13.0027. Generate bare earth models as triangulated
surfaces. Highest hit models were createdas a surface expression of all classified
points (excluding the noise and withheldclasses). All surface models were exported
as ESRI grids at a 3-foot pixel resolution.Software - TerraScan v.13.008 ArcMap v.
10.1 TerraModeler v.13.002
- The NOAA Coastal Services Center (CSC) downloaded topographic files in LAZ format
from PSLC's website.The files contained lidar easting, northing, elevation, intensity,
return number, class, scan angleand GPS time measurements. Entiat data were received
in Washington State Plane North, 4601 (feet) andreferenced to NAVD88 (feet).CSC performed
the following processing for data storage and Digital Coast provisioning purposes:1.
The All-Return LAZ files were cleared of variable lengths records.2. The All-Return
LAZ files were converted from a Projected Coordinate System (State Plane 4601)to a
Geographic Coordinate system (NAD83).3. The All-Return LAZ files were converted from
NAVD88 to ellipsoidal heights using Geoid03.
- 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: 2014-01-27
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