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GI010
LiDAR data (August 2008) for the Andrews Experimental Forest and Willamette National Forest study areas
Thomas
A.
Spies
USDA Forest Service;Pacific NW Research Station;3200 SW Jefferson Way
Corvallis
OR
97331
USA
(541) 750-7354
tom.spies@oregonstate.edu
thomas.spies@usda.gov
https://www.fs.fed.us/research/people/profile.php?alias=tspies
Theresa
J.
Valentine
USDA Forest Service;Pacific NW Research Station;3200 SW Jefferson Way
Corvallis
OR
97331
USA
(541) 750-7333
theresa.valentine56@gmail.com
Theresa
J.
Valentine
USDA Forest Service;Pacific NW Research Station;3200 SW Jefferson Way
Corvallis
OR
97331
USA
(541) 750-7333
theresa.valentine56@gmail.com
Abstractor
Thomas
A.
Spies
USDA Forest Service;Pacific NW Research Station;3200 SW Jefferson Way
Corvallis
OR
97331
USA
(541) 750-7354
tom.spies@oregonstate.edu
thomas.spies@usda.gov
https://www.fs.fed.us/research/people/profile.php?alias=tspies
Principal Investigator
Thomas
A.
Spies
USDA Forest Service;Pacific NW Research Station;3200 SW Jefferson Way
Corvallis
OR
97331
USA
(541) 750-7354
tom.spies@oregonstate.edu
thomas.spies@usda.gov
https://www.fs.fed.us/research/people/profile.php?alias=tspies
Creator
2016-08-03
Watershed Sciences, Inc. collected Light Detection and Ranging (LiDAR) data from HJ Andrews and the Willamette National Forest (WNF) on August 10-11, 2008. Total area of the study are is 17,705 acres. The total area of delivered LiDAR including 100 m buffer is 19,493 acres. This data set includes the base products delivered by Watershed Sciences, and derived products (hill shades, slope and aspect grids, and contours). The base products include the point cloud data (LAS format), and the derived bare-earth and highest-hits digital elevation models (DEM). The DEMs are at 1 meter cell size resolution. The bare-earth DEM is a representation of the topography of the area, with all the vegetation removed. The highest-hit DEM is a representation of the first object the LiDAR system struck during data capture. This includes the bare-earth topography with vegetation and structures. The vegetation DEM is the result of subtracting the bare-earth DEM from the highest-hit DEM. The elevations are the heights of the vegetation. The final products are in ESRI GRID digital format, with a 1 meter cell size resolution. Each cell in the GRID has a value that represents the modeled elevation (either total elevation or vegetation height) at that location. The resulting DEM's were used to create slope, aspect, hill shade, and contour data for the area.
stand structure
geology
geomorphology
spatial properties
geographic information systems
disturbance
landscape change
organic matter
LTER controlled vocabulary
disturbance
organic matter
LTER core research areas
Data were provided by the HJ Andrews Experimental Forest research program, funded by the National Science Foundation’s Long-Term Ecological Research Program (DEB 08-23380), US Forest Service Pacific Northwest Research Station, and Oregon State University.
LiDAR data was flown and processed by:
Watershed Sciences
257B SW Madison Street
Corvallis, OR 97333
215 SE 9th Ave, Suite 106
Portland, Oregon 97214
www.watershedsciences.comRelated FilesTitle: LIDAR REMOTE SENSING DATA COLLECTION: HJ Andrews & Willamette National Forest November 14th 2008Description: documentation of LiDAR collection by Watershed Sciences.URL: https://andrewsforest.oregonstate.edu/data/aerial/hj_andrews_report.pdf
Data Use Agreement:
The re-use of scientific data has the potential to greatly increase communication, collaboration and synthesis within and among disciplines, and thus is fostered, supported and encouraged. This Data Set is released under the Creative Commons license CC BY "Attribution" (see: https://creativecommons.org/licenses/by/4.0/). Creative Commons license CC BY - Attribution is a license that allows others to distribute, remix, tweak, and build upon your work (even commercially), as long as you are credited for the original creation. This license accommodates maximum dissemination and use of licensed materials.
It is considered professional conduct and an ethical obligation to acknowledge the work of other scientists. The Data User is asked to provide attribution of the original work if this data package is shared in whole or by individual parts or used in the derivation of other products. A recommended citation is provided for each Data Set in the Andrews LTER data catalog (see: http://andlter.forestry.oregonstate.edu/data/catalog/datacatalog.aspx). A generic citation is also provided for this Data Set on the website https://portal.edirepository.org in the summary metadata page. Data Users are thus strongly encouraged to consider consultation, collaboration and/or co-authorship with the Data Set Creator.
While substantial efforts are made to ensure the accuracy of data and associated documentation, complete accuracy of data sets cannot be guaranteed and all data are made available "as is." The Data User should be aware, however, that data are updated periodically and it is the responsibility of the Data User to check for new versions of the data. The data authors and the repository where these data were obtained shall not be liable for damages resulting from any use or misinterpretation of the data.
General acknowledgement: Data were provided by the HJ Andrews Experimental Forest research program, funded by the National Science Foundation's Long-Term Ecological Research Program (DEB 2025755), US Forest Service Pacific Northwest Research Station, and Oregon State University. Raster data files are available on-line. Raw data clouds are available by contacting Theresa Valentine. The size of the data clouds are large, so you will have to provide a portable disk drive. You will be asked to provide a short proposal of your intended use, to help coordinate efforts.
https://andlter.forestry.oregonstate.edu/data/abstract.aspx?dbcode=GI010
Andrews Experimental Forest and adjacent Blue River Watershed units within the Willamette National Forest, western Cascades, Oregon, USA.
-122.27746000
-122.09958000
44.28296100
44.19679700
2008-08-10
2008-08-11
The data was collected to provide a highly accurate and comprehensive base layer of elevation data and vegetation cover for the Andrews Experimental Forest, and several timber units in the adjacent area of the Willamette National Forest.The purpose of the data is to provide users with a very accurate view of the topography and vegetation of the study area. The data are suitable for creating visualizations, deriving watershed boundaries, creating stream networks, identifying structures such as roads and water features, vegetation modeling and calculating biomass, and for identifying landslides and geological features.
An update history is logged and maintained with each new
version of every dataset.
asNeeded
Study code and preliminary metadata established
Version1
2011-05-24
completed metadata for this study and made data available on-line in the new format, in it's new format.
Version2
2013-08-13
updated eml files for entities and fixed to the new data locations.
Version3
2013-10-25
added Tom Spies as originator
Version4
2013-10-31
updated groups
Version5
2013-10-31
new version needed for PASTA update.
Version6
2013-11-04
Added text file for point cloud data (entity 4) that describes how to obtain the data. Changed entity overview text.
Version7
2016-08-03
Information Manager
Andrews Forest LTER Program
US Forest Service Pacific Northwest Research Station
3200 SW Jefferson Way
Corvallis
OR
97331
hjaweb@fsl.orst.edu
http://andrewsforest.oregonstate.edu/
Theresa
J.
Valentine
USDA Forest Service;Pacific NW Research Station;3200 SW Jefferson Way
Corvallis
OR
97331
USA
(541) 750-7333
theresa.valentine56@gmail.com
Andrews Forest LTER Site
Forest Ecosystems and Society Department in Forestry
Oregon State University
201K Richardson Hall
Corvallis
OR
97331-5752
(541) 737-8480
lterweb@fsl.orst.edu
http://andrewsforest.oregonstate.edu/
Field Methods - GI010
2.1 Airborne Survey – Instrumentation and Methods
The LiDAR survey uses a Leica ALS50 Phase II laser system. For the HJ Andrews and Willamette NF study areas, the sensor scan angle was ±14o from nadir1 with a pulse rate designed to yield an average native density (number of pulses emitted by the laser system) of (Nadir refers to the perpendicular vector to the ground directly below the aircraft. Nadir is commonly used to measure the angle from the vector and is referred to a “degrees from nadir”.) 8 points per square meter over terrestrial surfaces. All study areas were surveyed with an opposing flight line side-lap of =50% (=100% overlap) to reduce laser shadowing and increase surface laser painting. The Leica ALS50 Phase II system allows up to four range measurements (returns) per pulse, and all discernable laser returns were processed for the output dataset.
It is not uncommon for some types of surfaces (e.g. dense vegetation or water) to return fewer pulses than the laser originally emitted. These discrepancies between ‘native’ and ‘delivered’ density will vary depending on terrain, land cover and the prevalence of water bodies.
To accurately solve for laser point position (geographic coordinates x, y, z), the positional coordinates of the airborne sensor and the attitude of the aircraft were recorded continuously throughout the LiDAR data collection mission. Aircraft position was measured twice per second (2 Hz) by an onboard differential GPS unit. Aircraft attitude was measured 200 times
per second (200 Hz) as pitch, roll and yaw (heading) from an onboard inertial measurement unit (IMU). To allow for post-processing correction and calibration, aircraft/sensor position and attitude data are indexed by GPS time.
Field Methods - GI010 (1)
2.2.1 Survey Control
Simultaneous with the airborne data collection mission, we conducted multiple static (1 Hz recording frequency) ground surveys over monuments with known coordinates (Table 1). Indexed by time, these GPS data are used to correct the continuous onboard measurements of aircraft position recorded throughout the mission. Multiple sessions were processed over the same monument to confirm antenna height measurements and reported position accuracy.
After the airborne survey, these static GPS data were then processed using triangulation with Continuously Operating Reference Stations (CORS) stations, and checked against the Online Positioning User Service (OPUS2) to quantify daily variance. Controls were located within 13 nautical miles of the mission area(s).
Processing Procedures - GI010
Applications and Work Flow Overview
Resolve kinematic corrections for aircraft position data using kinematic aircraft GPS and static ground GPS data.
Develop a smoothed best estimate of trajectory (SBET) file that blends post-processed aircraft position with attitude data (sensor heading, position, and attitude are calculated throughout the survey).
Calculate laser point position by associating SBET position to each laser point return time, scan angle, intensity, etc. Create raw laser point cloud data for the entire survey in *.las (ASPRS v1.1) format.
Import raw laser points into subset bins (less than 500 MB, to accommodate file size constraints in processing software). Perform manual relative accuracy calibration and filter for pits/birds. Classify ground points for individual flight lines (to be used for relative accuracy testing and calibration).
Test relative accuracy using ground classified points per each flight line. Perform automated line-to-line calibrations for system attitude parameters (pitch, roll, heading), mirror flex (scale) and GPS/IMU drift. Perform calibrations on ground classified points from paired flight lines. Every flight line is used for relative accuracy calibration.
Import position and attitude data. Classify ground and non-ground points. Assess statistical absolute accuracy via direct comparisons of ground classified points to ground RTK survey data. Convert data to orthometric elevations (NAVD88) by applying a Geoid03 correction. Create ground model as a triangulated surface and export as ArcInfo ASCII grids at the specified pixel resolution.
Software: Waypoint GPS v.7.60, IPAS v.1.4, ALS Post Processing Software, TerraScan v.7.012, TerraMatch v.7.004, TerraScan v.7.012, ArcMap v9.2
Processing Procedures - GI010 (1)
Aircraft Kinematic GPS and IMU Data
LiDAR survey datasets were referenced to the 1 Hz static ground GPS data collected over presurveyed monuments with known coordinates. While surveying, the aircraft collected 2 Hz kinematic GPS data, and the onboard inertial measurement unit (IMU) collected 200 Hz aircraft attitude data. Realm Survey Suite was used to process the kinematic corrections for the aircraft. The static and kinematic GPS data were then post-processed after the survey to obtain an accurate GPS solution and aircraft positions. POSPAC was used to develop a trajectory file that includes corrected aircraft position and attitude information. The trajectory data for the entire flight survey session were incorporated into a final smoothed best estimated trajectory (SBET) file that contains accurate and continuous aircraft positions and attitudes.
Processing Procedures - GI010 (2)
Laser Point Processing
Laser point coordinates were computed using the REALM software based on independent data from the LiDAR system (pulse time, scan angle), and aircraft trajectory data (SBET). Laser point returns (first through fourth) were assigned an associated (x, y, z) coordinate along with unique intensity values (0-255). The data were output into large LAS v. 1.1 files; each point maintains the corresponding scan angle, return number (echo), intensity, and x, y, z (easting, northing, and elevation) information.
Laser point data were imported into processing bins in TerraScan, and manual calibration was performed to assess the system offsets for pitch, roll, heading and scale (mirror flex). Using a geometric relationship developed by Watershed Sciences, each of these offsets was resolved
and corrected if necessary. LiDAR points were then filtered for noise, pits (artificial low points) and birds (true birds as well as erroneously high points) by screening for absolute elevation limits, isolated points and height above ground. Each bin was then manually inspected for remaining pits and birds and spurious points were removed. In a bin containing approximately 7.5-9.0 million points, an average of 50-100 points are typically found to be artificially low or high. Common sources of non-terrestrial returns are clouds, birds, vapor, haze, decks, brush piles, etc. Internal calibration was refined using TerraMatch. Points from overlapping lines were tested for internal consistency and final adjustments were made for system misalignments (i.e., pitch, roll, heading offsets and scale). Automated sensor attitude and scale corrections yielded 3-5 cm improvements in the relative accuracy. Once system misalignments were corrected, vertical GPS drift was then resolved and removed per flight line, yielding a slight improvement (less than 1 cm) in relative accuracy.
Long-Term Ecological Research
Matthew
G
Betts
Department of Forest Ecosystems and Society; 201E Richardson Hall; College of Forestry; Oregon State University
Corvallis
OR
97331
(541) 737-3841
matt.betts@oregonstate.edu
http://www.fsl.orst.edu/flel/index.htm
http://orcid.org/0000-0002-7100-2551
Principal Investigator
Michael
P.
Nelson
Department of Forest Ecosystems and Society; 201K Richarson Hall; College of Forestry; Oregon State University
Corvallis
OR
97331
541-737-9221
mpnelson@oregonstate.edu
http://www.michaelpnelson.com
http://orcid.org/0000-0001-6917-4752
Principal Investigator
Brooke
E.
Penaluna
brooke.penaluna@usda.gov
Brooke.Penaluna@oregonstate.edu
https://www.fs.fed.us/pnw/lwm/aem/people/penaluna.html
http://orcid.org/0000-0001-7215-770X
Principal Investigator
Catalina
Segura
Assistant Professor; Department of Forest Engineering, Resources, and Management; Oregon State University
Corvallis
OR
97331
541-737-6568
catalina.segura@oregonstate.edu
http://ferm.forestry.oregonstate.edu/facstaff/segura-catalina
http://orcid.org/0000-0002-0924-1172
Principal Investigator
David
Bell
david.bell@usda.gov
david.bell@oregonstate.edu
https://lemma.forestry.oregonstate.edu/about/david-bell
http://orcid.org/0000-0002-2673-5836
Principal Investigator
The H.J. Andrews Experimental Forest is a living laboratory that provides unparalleled opportunities for the study of forest and stream ecosystems in the central Cascade Range of Oregon. Since 1980, as a part of the National Science Foundation Long Term Ecological Research (NSF-LTER) program, the Andrews Experimental Forest has become a leader in the analysis of forest and stream ecosystem dynamics.
Long-term field experiments and measurement programs have focused on climate dynamics, streamflow, water quality, and vegetation succession. Currently researchers are working to develop concepts and tools needed to predict effects of natural disturbance, land use, and climate change on ecosystem structure, function, and species composition.
The Andrews Experimental Forest is administered cooperatively by the USDA Forest Service Pacific Northwest Research Station, Oregon State University and the Willamette National Forest. Funding for the research program comes from the National Science Foundation (NSF), US Forest Service Pacific Northwest Research Station, Oregon State University, and other sources.
Data were provided by the HJ Andrews Experimental Forest research program, funded by the National Science Foundation's Long-Term Ecological Research Program (DEB 2025755), US Forest Service Pacific Northwest Research Station, and Oregon State University. National Science Foundation: DEB1440409
The Andrews Forest is situated in the western Cascade Range of Oregon, and covers the entire 15,800-acre (6400-ha) drainage basin of Lookout Creek. Elevation ranges from 1350 to 5340 feet (410 to 1630 m). Broadly representative of the rugged mountainous landscape of the Pacific Northwest, the Andrews Forest contains excellent examples of the region's conifer forests and associated wildlife and stream ecosystems. These forests are among the tallest and most productive in the world, with tree heights of often greater than 250 ft (75 m). Streams are steep, cold and clean, providing habitat for numerous aquatic organisms.