Hubbard, T.D.
Koehler, R.D.
Combellick, R.A.
2011
High-resolution lidar data for Alaska infrastructure corridors
vector digital data, document
Raw Data File
RDF 2011-3
Fairbanks, AK, USA
Alaska Division of Geological & Geophysical Surveys
291 p.
http://dx.doi.org/10.14509/22722
In advance of design, permitting, and construction of a pipeline to deliver North Slope natural gas to out-of-state customers and Alaska communities, the Division of Geological & Geophysical Surveys (DGGS) has acquired lidar (Light Detection and Ranging) data along proposed pipeline routes, nearby areas of infrastructure, and regions where significant geologic hazards have been identified. Lidar data will serve multiple purposes, but have primarily been collected to (1) evaluate active faulting, slope instability, thaw settlement, erosion, and other engineering constraints along proposed pipeline routes, and (2) provide a base layer for the state-federal GIS database that will be used to evaluate permit applications and construction plans. This shapefile contains kinematicly-corrected trajectory data presented as a 1Hz sampling of the original 200 Hz Smooth-Best estimate Trajectory files (SBET).
Provide aircraft position and attitude during acquisition of lidar data.
This metadata file has been written to document and describe the SBET data generated for this project. Information about accuracy and quality of lidar data can be found in quality control reports provided by DOGAMI and delivery reports provided by Watershed Sciences, Inc. Individual reports were provided for each delivery set and have been combined by DGGS into comprehensive quality control and delivery reports. These documents are organized according to how data were delivered to DGGS. A description of information pertaining to the downloadable files can be found in the quality control and delivery reports. The DGGS metadata standard extends the FGDC standard to also include several elements that are required to facilitate our internal data management. These elements, referred to as "layers," group and describe files that have intrinsic logical or topological relationships. This dataset describes a single layer titled:
>sbet: Smoothed Best Estimate Trajectory shapefile
2010
2011
ground condition
As needed
-150.82
-141.00
70.38
61.04
ISO 19115 Topic Category
geoscientificInformation
Alaska Division of Geological & Geophysical Surveys
Alaska Pipeline
Gasline
Geomorphology
Lidar
Proposed Natural Gas Pipeline
Smoothed Best Estimate Of Trajectory (SBET)
Alaska Division of Geological & Geophysical Surveys
Alaska Highway Corridor
Alaska, State of
Trans-Alaska Pipeline
This dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys
Any hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. The user specifically agrees not to misrepresent these datasets, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.
Alaska Division of Geological & Geophysical Surveys
James Weakland
GIS Analyst
mailing and physical
3354 College Road
Fairbanks
AK
99709-3707
USA
(907)451-5029
(907)451-5020
dggsgis@alaska.gov
Data collection was supported by funding from the Department of Natural Resources (DNR), Division of Geological & Geophysical Surveys (DGGS), the Alaska Gas Pipeline Project Office, the Office of the Federal Coordinator, and the Alaska Gasline Development Corporation (AGDC). Lidar data were collected and processed by Watershed Sciences, Inc. of Corvallis, OR. Survey data were collected by McClintock Land Associates of Eagle River, AK. Lidar data and derivative products were checked for quality, completeness, and accuracy by State of Oregon Department of Geology & Mineral Industries based in Portland, OR.
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.3000
Lidar survey datasets were referenced to the 1 Hz static ground GPS data collected over pre-surveyed monuments with known coordinates. While surveying, the aircraft collected 2 Hz kinematic GPS data, and the on-board inertial measurement unit (IMU) collected 200 Hz aircraft attitude data. Waypoint GPS v.8.10 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. IPAS v.1.35 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.
Consistency refers to lidar elevation differences between overlapping flight lines. Consistency errors are created by poor lidar system calibration settings associated with sensor platform mounting. Errors in consistency manifest as vertical offsets between individual flight lines. Consistency offsets were measured using the "Find Match" tool within the TerraMatch© software toolset. This tool uses aircraft trajectory information linked to the lidar point cloud data to quantify flight line-to-flight line offsets.
Lidar data have been checked for accuracy and completeness. Please refer to the lidar delivery report and lidar QC report for details about data accuracy completeness for individual delivery sets.
The positional coordinates and attitude of the aircraft were recorded continuously throughout the lidar collection mission. Aircraft position was measured twice per second (2 Hz) by an on-board differential GPS unit during periods with PDOP less than or equal to 3 and with at least 6 satellites in view. Aircraft position was measured twice per second (200 Hz) as pitch, roll and yaw (heading) from an on-board inertial measurement unit (IMU). To allow for post-processing correction and calibration, aircraft/sensor position and attitude are indexed by GPS time. During the lidar survey, static (1 Hz recording frequency) ground surveys were conducted over the survey control monuments. All control monuments were observed for a minimum of two survey sessions lasting no fewer than 4 hours. At the beginning of every session, the tripod and antenna were reset. Indexed by time, GPS data were used to correct the continuous on-board measurements of aircraft position recorded throughout the mission. Control monuments were located within 13 nautical miles of the survey area.
The positional coordinates and attitude of the aircraft were recorded continuously throughout the lidar collection mission. Aircraft position was measured twice per second (2 Hz) by an on-board differential GPS unit during periods with PDOP less than or equal to 3 and with at least 6 satellites in view. Aircraft position was measured twice per second (200 Hz) as pitch, roll and yaw (heading) from an on-board inertial measurement unit (IMU). To allow for post-processing correction and calibration, aircraft/sensor position and attitude are indexed by GPS time. During the lidar survey, static (1 Hz recording frequency) ground surveys were conducted over the survey control monuments. All control monuments were observed for a minimum of two survey sessions lasting no fewer than 4 hours. At the beginning of every session, the tripod and antenna were reset. Indexed by time, GPS data were used to correct the continuous on-board measurements of aircraft position recorded throughout the mission. Control monuments were located within 13 nautical miles of the survey area.
Acquisition: The lidar data were collected between September and October 2010 and between May and July 2011.The survey used the Leica ALS60 system. Ground-level GPS and aircraft IMU were collected during the flight. The following settings were used: Survey altitude (AGL) = 900 meters, Mirror scan rate = 55 Hz, Pulse rate = 105 kHz, Single pulse mode, Field of view (FOV) = 28 degree (+/- 8 degrees from nadir), 60% side lap (>100% overlap), Laser swath width = 448 meters, Airspeed = 105 knots per hour, Footprint = 24 cm. On each collection date, there was no cloud cover below 5000 feet and no precipitation. Flight-line specifics are provided in the attribute tables of the SBET shapefiles. Ancillary equipment includes: Trimble R7 receivers, Trimble R8 receivers, Trimble HPB450 radios, and Trimble TSC2 controllers.
2010, 2011
All SBET shapefiles for each delivery were combined into a single shapefile containing all of the SBET data. Data were reprojected in Alaska Albers Equal Area Conic.
2012
A metadata file was created to generally describe data acquisition of lidar and also to describe the smooth best estimated trajectory (SBETS) files.
2012
point
Alaska Albers Equal Area Conic
55
65
-154
50
0
0
coordinate pair
0.000001
0.000001
meters
sbet
North American Datum of 1983
Geodetic Reference System 80
6378137
298.257222
rdf2011-3-sbet
Kinematicly-corrected trajectory data presented as a 1Hz sampling of the original 200 Hz Smooth-Best estimate Trajectory files (SBET).
this report
sbet
GPS_Time
GPS_Time (s) of data collection
Watershed Sciences, Inc.
56.50408
604792.57899
Height
Height (m) of plane during data collection: NAVD88 Geoid 09
Watershed Sciences, Inc.
18.837
5159.32
Roll
Roll (deg) of the plane during data collection
Watershed Sciences, Inc.
-41.478219
38.613914
Pitch
Pitch (deg) of the plane during data collection
Watershed Sciences, Inc.
-33.227986
22.134247
Heading
Heading (deg) of the plane during data collection
Watershed Sciences, Inc.
-179.999985
179.999816
E_vel
Easting velocity (m/s) of the plane during data collection
Watershed Sciences, Inc.
-97.92675781
94.57273102
N_vel
Northing velocity (m/s) of the plane during data collection
Watershed Sciences, Inc.
-91.3674469
111.9095993
H_vel
Height velocity (m/s) of the plane during data collection
Watershed Sciences, Inc.
-20.27645302
23.23749542
Std_E
Standard deviation around Easting (m) of the plane during data collection
Watershed Sciences, Inc.
0.003
0.036
Std_N
Standard deviation around Northing (m) of the plane during data collection
Watershed Sciences, Inc.
0.003
0.032
Std_H
Standard deviation around Height (m) of the plane during data collection
Watershed Sciences, Inc.
0.005
0.047
Std_Roll
Standard deviation around Roll (arcSec) of the plane during data collection
Watershed Sciences, Inc.
2.2
17.8
Std_Pitch
Standard deviation around Pitch (arcSec) of the plane during data collection
Watershed Sciences, Inc.
2.2
20.1
Std_Head
Standard deviation around Heading (arcSec) of the plane during data collection
Watershed Sciences, Inc.
3.5
158.8
Std_E_vel
Standard deviation around Easting velocity (m/s) of the plane during data collection
Watershed Sciences, Inc.
0.001
0.006
Std_N_vel
Standard deviation around Northing Velocity (m/s) of the plane during data collection
Watershed Sciences, Inc.
0.001
0.008
Std_H_vel
Standard deviation around Height Velocity (m/s) of the plane during data collection
Watershed Sciences, Inc.
0.001
0.006
Alaska Division of Geological & Geophysical Surveys
mailing and physical
3354 College Road
Fairbanks
AK
99709-3707
USA
(907)451-5020
(907)451-5050
dggspubs@alaska.gov
8 am to 4:30 pm, Monday through Friday, except State holidays
Please view our website (http://www.dggs.alaska.gov) for the latest information on available data. Please contact us using the e-mail address provided above when possible.
RDF 2011-3
The State of Alaska makes no express or implied warranties (including warranties of merchantability and fitness) with respect to the character, function, or capabilities of the electronic services or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity, whether from the use of the electronic services or products, any failure thereof, or otherwise, and in no event will the State of Alaska's liability to the requestor or anyone else exceed the fee paid for the electronic service or product.
Current publication is not available on paper. To purchase other printed reports and maps, contact DGGS by phone (907-451-5020), e-mail (dggspubs@alaska.gov), or fax (907-451-5050). Payment accepted: Cash, check, money order, VISA, or MasterCard.
Contact DGGS for current pricing
vector digital data
http://dx.doi.org/10.14509/22722
Free download
20120725
Metadata manager
mailing and physical
3354 College Road
Fairbanks
AK
99709-3707
USA
(907)451-5020
FGDC Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998
If the user has modified the data in any way they are obligated to describe the types of modifications they have performed in the supporting metadata file. User specifically agrees not to imply that changes they made were approved by the Alaska Department of Natural Resources or Division of Geological & Geophysical Surveys.
http://www.dggs.alaska.gov/metadata/dggs.ext
dggs metadata extensions