Short Citation:
OCM Partners, 2021: 2017 USGS 3DEP Lidar: Fairbanks, AK (QL1 & QL2), https://www.fisheries.noaa.gov/inport/item/55358.

Item Identification

Title: 2017 USGS 3DEP Lidar: Fairbanks, AK (QL1 & QL2)
Short Name: ak2017_fairbanks_m8663_metadata.xml
Status: Completed
Publication Date: 2018-04-18
Abstract:

In May 2017, Quantum Spatial (QSI) was contracted by the United States Geological Survey (USGS) to collect QL1 and QL2 Light Detection and Ranging (LiDAR) data over approximately 1.8 million acres of land for the Fairbanks 3DEP mapping site in Alaska (Task Order G17PD00606). Data were collected to aid USGS in assessing the topographic and geophysical properties of the study area to support the 3DEP mapping initiative.

Geographic Extent: The QL1 area encompasses 248,555 acres and the QL2 area encompasses 1,186,822 acres.

Dataset Description: RAW flight line swaths were processed to create 6,268 classified LAS 1.4 files delineated in 3000 x 3000 ft tiles tiles. Each LAS file contains LiDAR point information, which has been calibrated, controlled, and classified. LAS files have been edited to the extent of the buffered boundary. Additional derived products include intensity images, hydro-flattened DEMs, highest hit surface models, 2ft contours, and 3D breaklines of rivers and lakes within the study area.

Ground Conditions: Data was acquired during conditions with an absence of snow, high water, ground fog and/or clouds below the flight altitudes.

The NOAA Office for Coastal Management (OCM) downloaded 1203 laz files from ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_AK_FairbanksNSB_QL1_2017_LAS_2018/ and 6268 laz files from ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_AK_FairbanksNSB_QL2_2017_LAS_2018 and processed the data to the Data Access Viewer (DAV) and https.

Hydro and bridge breaklines are also available. These data are available for download at the link provided in the URL section of this metadata record. Please note that these products have not been reviewed by the NOAA Office for Coastal Management (OCM) and any conclusions drawn from the analysis of this information are not the responsibility of NOAA or OCM.

Purpose:

The purpose of the lidar data was to produce a high accuracy 3D dataset that meets all necessary standards laid out by the 3DEP initiative.

The raw lidar point cloud data were used to create classified lidar LAS files, intensity images, hydro-flattened DEMs, highest hit surface models, 2ft contours, and 3D breaklines of rivers and lakes within the study area.

Supplemental Information:

CONTRACTOR: Quantum Spatial, Inc.

Ground Control Points were acquired DOWL Engineering. All Lidar data acquisition, calibration, and follow-on processing were completed by the prime contractor.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "National Geospatial Program Lidar Base Specification Version 1.2",

"ldrsens" : "ALS-70",

"ldrmaxnr" : "15",

"ldrnps" : ".71",

"ldrdens" : "2",

"ldranps" : "0.71",

"ldradens" : "2",

"ldrfltht" : "1600",

"ldrfltsp" : "145",

"ldrscana" : "30",

"ldrscanr" : "50.2",

"ldrpulsr" : "175",

"ldrpulsd" : "9",

"ldrpulsw" : "2.698",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "22",

"ldrswatw" : "857",

"ldrswato" : "28",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12B"

},

"ldraccur" : {

"ldrchacc" : "0.5",

"rawnva" : "0.376 ft",

"rawnvan" : "321"

},

"lasinfo" : {

"lasver" : "1.4",

"lasprf" : "6",

"laswheld" : "Withheld points are identified using the standard LAS witheld bit.",

"lasolap" : "Swath overage points are identified using the standard LAS overlap bit.",

"lasintr" : "16",

"lasclass" : {

"clascode" : "1",

"clasitem" : "Processed, but Unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Bare earth ground"

},

"lasclass" : {

"clascode" : "3",

"clasitem" : "Low Vegetation (0.5m - 2m)"

},

"lasclass" : {

"clascode" : "4",

"clasitem" : "Medium Vegetation (2m - 6m)"

},

"lasclass" : {

"clascode" : "5",

"clasitem" : "High Vegetation (6m+)"

},

"lasclass" : {

"clascode" : "6",

"clasitem" : "Buildings (automated classification only)"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "Low Noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "10",

"clasitem" : "Ignored Ground Near Breakline"

},

"lasclass" : {

"clascode" : "17",

"clasitem" : "Bridge Decks"

}

}}

Keywords

Theme Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Science Keywords Earth Science > Land Surface > Topography > Terrain Elevation
ISO 19115 Topic Category elevation
None DEM
None digital elevation model
None Elevation data
None erosion
None LAS Point Cloud
None laser
None lidar
None model
None remote sensing
None Topography

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords Continent > North America > United States Of America > Alaska
Global Change Master Directory (GCMD) Location Keywords Vertical Location > Land Surface
None Fairbanks

Instrument Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Instrument Keywords Earth Remote Sensing Instruments > Active Remote Sensing > Profilers/Sounders > Lidar/Laser Sounders > LIDAR > Light Detection and Ranging

Platform Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Platform Keywords Aircraft > Aircraft

Physical Location

Organization: Office for Coastal Management
City: Charleston
State/Province: SC

Data Set Information

Data Set Scope Code: Data Set
Data Set Type: Elevation
Maintenance Frequency: Unknown
Data Presentation Form: Point Cloud (Digital)
Distribution Liability:

Any conclusions drawn from the analysis of this information are not the responsibility of Quantum Spatial, Inc, USGS, NOAA, the Office for Coastal Management or its partners.

Data Set Credit: Quantum Spatial, Inc. coordinated the LiDAR acquisition and processed the data., Quantum Spatial, Inc.

Support Roles

Data Steward

CC ID: 814131
Date Effective From: 2018
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Distributor

CC ID: 814132
Date Effective From: 2018
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Metadata Contact

CC ID: 814133
Date Effective From: 2018
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Point of Contact

CC ID: 814134
Date Effective From: 2018
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Extents

Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 814137
W° Bound: -148.712735
E° Bound: -145.410639
N° Bound: 65.274619
S° Bound: 64.22307

Extent Group 1 / Time Frame 1

CC ID: 814136
Time Frame Type: Range
Start: 2017-05-28
End: 2017-09-03
Description:

Collection period for the QL2 area.

Extent Group 1 / Time Frame 2

CC ID: 814163
Time Frame Type: Range
Start: 2017-06-13
End: 2017-07-01
Description:

Collection period for the QL1 area.

Access Information

Security Class: Unclassified
Data Access Procedure:

Data is available online for bulk and custom downloads.

Data Access Constraints:

None

Data Use Constraints:

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.

Distribution Information

Distribution 1

CC ID: 814138
Start Date: 2018
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8663
Distributor:
File Name: Customized Download
Description:

Create custom data files by choosing data area, product type, map projection, file format, datum, etc. A new metadata will be produced to reflect your request using this record as a base.

Compression: Zip

Distribution 2

CC ID: 814139
Start Date: 2018
End Date: Present
Download URL: https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8663
Distributor:
File Name: Bulk Download
Description:

Bulk download of data files in LAZ format, geographic coordinates, orthometric heights. Note that the vertical datum (hence elevations) of the files here are different than described in this document.

File Type: LAZ

URLs

URL 1

CC ID: 814126
URL: https://coast.noaa.gov/
Name: NOAA's Office for Coastal Management (OCM) website
URL Type:
Online Resource
File Resource Format: HTML
Description:

Information on the NOAA Office for Coastal Management (OCM)

URL 2

CC ID: 814127
URL: https://coast.noaa.gov/dataviewer/
Name: NOAA's Office for Coastal Management (OCM) Data Access Viewer (DAV)
URL Type:
Online Resource
File Resource Format: HTML
Description:

The Data Access Viewer (DAV) allows a user to search for and download elevation, imagery, and land cover data for the coastal U.S. and its territories. The data, hosted by the NOAA Office for Coastal Management, can be customized and requested for free download through a checkout interface. An email provides a link to the customized data, while the original data set is available through a link within the viewer.

URL 3

CC ID: 814128
URL: https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8663/supplemental/ak2017_fairbanks_m8663.kmz
Name: Browse graphic
URL Type:
Browse Graphic
File Resource Format: KML
Description:

This graphic displays the footprint for this lidar data set.

URL 4

CC ID: 814129
URL: https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8663/supplemental/Fairbanks_3DEP_LiDAR_Technical_Data_Report.pdf
Name: Dataset report
URL Type:
Online Resource
File Resource Format: PDF
Description:

Link to data set report.

URL 5

CC ID: 815631
URL: https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8663/breaklines/
URL Type:
Online Resource
Description:

Link to the data set breaklines.

Technical Environment

Description:

LASTools, TerraPOS, Cloudpro 1.2.4, Microstation Version 8i, TerraScan Version 17, TerraModeler Version 17, ESRI ArcGIS 10.3, Windows 7 Operating System

Data Quality

Vertical Positional Accuracy:

The specifications require that raw Non-vegetated Vertical Accuracy (NVA) be computed from the both the raw lidar point cloud swath files and the derived DEMs. Additionally, Vegetated Vertical Accuracy (VVA) is also to be computed from the derived DEMS. The NVA check points were collected by DOWL Engineering and distributed throughout the project as feasible. These check points were not used in the calibration or post processing of the lidar point cloud data. The VVA was collected by DOWL Engineering and tested with independent check points located in vegetated terrain, also witheld from the calibration and post processing of the lidar point cloud data and distributed throughout the project area as feasible. Specifications for this project require that the NVA be 19.6 cm (Swath, DEM) meters or better AccuracyZ at 95% confidence level and that the VVA be 29.4 cm (DEM) or better AccuracyZ at the 95th percentile. The following accuracy assessment reflects the combined accuracy results of QL1 and QL2 data.

0.115 m (0.376 ft) AccuracyZ at the 95 percent Confidence Interval for RAW LAS NVA.

DEM NVA: 0.094 m (0.309 ft) AccuracyZ at the 95 percent Confidence Interval.

DEM VVA: 0.209 m (0.687 ft) AccuracyZ at the 95th percentile.

NVA was tested using 321 surveyed check points. Elevations interpolated from the unclassified lidar surface were compared to the elevation values of the surveyed NVA check points. The RMSE was computed to be 0.058 m (0.192 ft) resulting in an AccuracyZ at the 95% confidence level of 0.115 m (0.376 ft).

The NVA check points were also compared to the elevations of the derived bare earth DEMs. The RMSE was computed to be 0.048 m (0.158 ft) resulting in an AccuracyZ of 0.094 m (0.309 ft) at the 95% confidence level. NVA AccuracyZ has been tested and meets the required 19.6 cm at 95% confidence level using (RMSEz * 1.9600) for both the raw lidar point cloud and derived DEMs, as defined by the National Standards for Spatial Data Accuracy (NSSDA) and herein reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines.

Elevations of the 219 VVA check points were compared to the elevations of the derived bare earth DEMs. The RMSE was computed to be 0.113 m (0.371 ft) and resulted in an AccuracyZ of 0.209 m (0.687 ft) at the 95th percentile. AccuracyZ has been tested on the derived bare earth DEMs and meets the required 29.4 cm (DEM) VVA using the 95th percentile of the absolute value of all vertical errors in all combined vegetation classes as defined by the National Standards for Spatial Data Accuracy (NSSDA); and herein reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines.

Completeness Report:

LAS files include all data points collected. No points have been removed or excluded. Shaded relief images have been visually inspected for data errors such as pits, border artifacts, and shifting. LiDAR flight lines have been examined to ensure consistent elevation values across overlapping flight lines. The raw point cloud is of good quality and data passes Vertical Accuracy specifications.

Conceptual Consistency:

Classified LAS files were tested by QSI for both vertical and horizontal accuracy. All data is seamless from one tile to the next, no gaps or no data areas.

Lineage

Sources

Base Station Control

CC ID: 814118
Contact Role Type: Originator
Contact Type: Organization
Contact Name: Quantum Spatial
Publish Date: 2018-04-18
Extent Type: Discrete
Extent Start Date/Time: 2018-04-18
Source Contribution:

This data source was used (along with the airborne GPS/IMU data) to georeference the LiDAR point cloud data.

Ground Control Quality Check Points

CC ID: 814121
Contact Role Type: Originator
Contact Type: Organization
Contact Name: Quantum Spatial
Publish Date: 2018-04-18
Extent Type: Discrete
Extent Start Date/Time: 2018-04-18
Source Contribution:

This data source was used to assess the accuracy of LiDAR point cloud data.

LiDAR RAW Data

CC ID: 814122
Contact Role Type: Originator
Contact Type: Organization
Contact Name: Quantum Spatial
Publish Date: 2018-04-18
Extent Type: Range
Extent Start Date/Time: 2017-05-28
Extent End Date/Time: 2017-09-03
Source Contribution:

This data source was used to populate the LiDAR point cloud data.

Smooth Best Estimate Trajectories

CC ID: 814119
Contact Role Type: Originator
Contact Type: Organization
Contact Name: Quantum Spatial
Publish Date: 2018-04-18
Extent Type: Discrete
Extent Start Date/Time: 2018-04-18
Source Contribution:

This data source was used (along with base station control data) to georeference the LiDAR point cloud data.

Supplemental Ground Control Points

CC ID: 814120
Contact Role Type: Originator
Contact Type: Organization
Contact Name: Quantum Spatial
Publish Date: 2018-04-18
Extent Type: Discrete
Extent Start Date/Time: 2018-04-18
Source Contribution:

This data source was used to refine airborne GPS positional accuracy during the calibration process.

Process Steps

Process Step 1

CC ID: 814123
Description:

LiDAR Pre-Processing:

1. Review flight lines and data to ensure complete coverage of the study area and positional accuracy of the laser points.

2. Resolve kinematic corrections for aircraft position data using kinematic aircraft GPS and static ground GPS data.

3. Develop a smoothed best estimate of trajectory (SBET) file that blends post-processed aircraft position with sensor head position and attitude recorded throughout the survey.

4. 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 format. Convert data to orthometric elevations by applying a geoid12b correction.

5. Import raw laser points into manageable blocks (less than 500 MB) to perform manual relative accuracy calibration and filter erroneous points. Classify ground points for individual flight lines.

6. Using ground classified points per each flight line, test the relative accuracy. Perform automated line-to-line calibrations for system attitude parameters (pitch, roll, heading), mirror flex (scale) and GPS/IMU drift. Calculate calibrations on ground classified points from paired flight lines and apply results to all points in a flight line. Use every flight line for relative accuracy calibration.

7. Adjust the point cloud by comparing ground classified points to supplemental ground control points.

Process Date/Time: 2018-04-16 00:00:00

Process Step 2

CC ID: 814124
Description:

LiDAR Post-Processing:

1. Classify data to ground and other client designated classifications using proprietary classification algorithms.

2. Manually QC data classification

3. After completion of classification and final QC approval, calculate NVA and VVA, and density information for the project using ground control quality check points.

Process Date/Time: 2018-04-16 00:00:00

Process Step 3

CC ID: 814164
Description:

The NOAA Office for Coastal Management (OCM) downloaded 1203 laz files from ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_AK_FairbanksNSB_QL1_2017_LAS_2018/ and 6268 laz files from ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_AK_FairbanksNSB_QL2_2017_LAS_2018. The data were in Alaska State Plane, Zone 3 NAD83 2011, US survey feet, coordinates and NAVD88 (Geoid12B) elevations in feet. The data were classified as: 1 - Unclassified, 2 - Ground, 3 - Low vegetation (0.5 - 2 m), 4 - Medium vegetation (2 - 6 m), 5 - High vegetation (greater than 6 m), 6 - Buildings, 7 - Low Noise, 9 - Water, 10 - Ignored Ground, 17 - Bridge Decks. OCM processed all classifications of points to the Digital Coast Data Access Viewer (DAV). Classes available on the DAV are: 1, 2, 3, 4, 5, 6, 7, 9, 10, 17.

OCM performed the following processing on the data for Digital Coast storage and provisioning purposes:

1. The LAStools software script lasinfo was run on the laz files to check for errors.

2. An internal OCM script was run to check the number of points by classification and by flight ID, and the gps and intensity ranges.

3. Internal OCM scripts were run on the laz files to convert from orthometric (NAVD88) elevations to ellipsoid elevations using the Geoid 12B model, to convert from elevations in feet to meters, to convert from Alaska State Plane, Zone 3 coordinates in US survey feet to geographic coordinates, to assign the geokeys, to sort the data by gps time and zip the data to database and to http.

Process Date/Time: 2019-01-24 00:00:00
Process Contact: Office for Coastal Management (OCM)

Catalog Details

Catalog Item ID: 55358
Metadata Record Created By: Rebecca Mataosky
Metadata Record Created: 2019-01-17 11:09+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2019-07-02 15:17+0000
Metadata Record Published: 2019-01-25
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Next Review Date: 2020-01-26