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Short Citation:
OCM Partners, 2023: 2018 WA DNR Lidar DEM: Green River Watershed, WA, https://www.fisheries.noaa.gov/inport/item/67440.

Item Identification

Title: 2018 WA DNR Lidar DEM: Green River Watershed, WA
Status: Completed
Creation Date: 2019
Abstract:

No metadata record was provided with the data. This record is populated with information from the Quantum Spatial, Inc. technical report downloaded from the Washington Dept. of Natural Resources Washington Lidar Portal. The technical report is available for download from the link provided in the URL section of this metadata record.

In September 2017, Quantum Spatial (QSI) was contracted by Washington State Department of Natural Resources (WADNR) to collect Light Detection and Ranging (LiDAR) data and digital imagery in the winter of 2017 and summer of 2018, respectively, for the Green River Watershed site in Washington. This contract also incorporates LiDAR data collection and processing over additional sites, including the Green River Corridor, Tacoma Water Service Area, and a selected portion of the Green River Watershed which will be used for Forestry Analytics. Unfavorable weather conditions delayed the acquisition of LiDAR data for the Green River Watershed to the winter of 2018. This data report and delivery encompasses only the Green River Watershed LiDAR delivery. Data were collected to aid WADNR in assessing the topographic and geophysical properties of the study area.

In addition to these bare earth Digital Elevation Model (DEM) data, the lidar point data that these DEM data were created from are also available. These data are available for download at the link provided in the URL section of this metadata record.

Purpose:

Data were collected to aid WADNR in assessing the topographic and geophysical properties of the study area.

Keywords

Theme Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION > DIGITAL ELEVATION/TERRAIN MODEL (DEM)
ISO 19115 Topic Category
elevation

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA
Global Change Master Directory (GCMD) Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > WASHINGTON
Global Change Master Directory (GCMD) Location Keywords
VERTICAL LOCATION > LAND SURFACE

Instrument Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Instrument Keywords
LIDAR > Light Detection and Ranging

Platform Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Platform Keywords
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: None Planned
Data Presentation Form: Model (digital)
Distribution Liability:

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

Data Set Credit: Quantum Spatial, Inc., Washington Dept. of Natural Resources

Support Roles

Data Steward

CC ID: 1176546
Date Effective From: 2022
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: 1176545
Date Effective From: 2022
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: 1176547
Date Effective From: 2022
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: 1176548
Date Effective From: 2022
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: 1176571
W° Bound: -121.861506
E° Bound: -121.296427
N° Bound: 47.358623
S° Bound: 47.116988

Extent Group 1 / Time Frame 1

CC ID: 1176568
Time Frame Type: Discrete
Start: 2018-11-08

Extent Group 1 / Time Frame 2

CC ID: 1176569
Time Frame Type: Range
Start: 2018-11-11
End: 2018-11-12

Extent Group 1 / Time Frame 3

CC ID: 1176570
Time Frame Type: Discrete
Start: 2017-12-10

Spatial Information

Spatial Representation

Representations Used

Grid: Yes

Reference Systems

Reference System 1

CC ID: 1176573

Coordinate Reference System

CRS Type: Projected
EPSG Code: EPSG:2927
EPSG Name: NAD83(HARN) / Washington South (ftUS)
See Full Coordinate Reference System Information

Reference System 2

CC ID: 1176574

Coordinate Reference System

CRS Type: Vertical
EPSG Code: EPSG:6360
EPSG Name: NAVD88 height (ftUS)
See Full Coordinate Reference System Information

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: 1176550
Start Date: 2021-07-15
End Date: Present
Download URL: https://chs.coast.noaa.gov/htdata/raster5/elevation/WA_Green_Rvr_DEM_2018_9541
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2022 - Present)
File Name: Bulk Download
Description:

Bulk download of data files in GeoTiff format, WA State Plane South NAD83(HARN) US survey feet coordinates and orthometric heights in feet.

File Type: GeoTIFF

Distribution 2

CC ID: 1176549
Start Date: 2021-07-15
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=9541/details/9541
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2022 - Present)
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. Change to an orthometric vertical datum is one of the many options.

File Type: Zip
Compression: Zip

URLs

URL 1

CC ID: 1176551
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 2

CC ID: 1176552
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9536/supplemental/wa2018_green_rvr_m9536.kmz
Name: Browse graphic
URL Type:
Browse Graphic
File Resource Format: KML
Description:

This graphic displays the footprint for this lidar data set.

URL 3

CC ID: 1176553
URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=9536/details/9536
Name: Custom Point Download
URL Type:
Online Resource
File Resource Format: Zip
Description:

Link to custom download, from the Data Access Viewer (DAV), the lidar point data from which these raster Digital Elevation Model (DEM) data were created.

URL 4

CC ID: 1176556
URL: https://lidarportal.dnr.wa.gov/download?ids=1251
Name: Lidar Report
URL Type:
Online Resource
File Resource Format: pdf
Description:

Link to the Quantum Spatial, Inc. Technical Lidar Report from the Washington Lidar Portal.

Data Quality

Vertical Positional Accuracy:

Absolute accuracy was assessed using Non-Vegetated Vertical Accuracy (NVA) reporting designed to meet guidelines presented in the FGDC National Standard for Spatial Data Accuracy2. NVA compares known ground check point data that were withheld from the calibration and post-processing of the LiDAR point cloud to the triangulated surface generated by the unclassified LiDAR point cloud as well as the derived gridded bare earth DEM. NVA is a measure of the accuracy of LiDAR point data in open areas where the LiDAR system has a high probability of measuring the ground surface and is evaluated at the 95% confidence interval (1.96 * RMSE).

The mean and standard deviation (sigma) of divergence of the ground surface model from quality assurance point coordinates are also considered during accuracy assessment. These statistics assume the error for x, y and z is normally distributed, and therefore the skew and kurtosis of distributions are also considered when evaluating error statistics. For the Green River Watershed survey, eight ground check points were withheld from the calibration and post processing of the LiDAR point cloud, with resulting non-vegetated vertical accuracy of 0.313 feet (0.095 meters) at 95% confidence or 4.9 cm RMSE as compared to unclassified LAS, and 0.178 feet (0.054 meters) as compared to the bare earth DEM, with 95% confidence.

Quality Control Procedures Employed:

QSI has high standards and adheres to best practices in all efforts. In the laboratory, quality checks are built in throughout processing steps, and automated methodology allows for rapid data processing. QSI's innovation and adaptive culture rises to technical challenges and the needs of clients like Washington DNR. Reporting and communication to our clients are prioritized through regular updates and meetings.

Data Management

Have Resources for Management of these Data Been Identified?: Yes
Approximate Percentage of Budget for these Data Devoted to Data Management: Unknown
Do these Data Comply with the Data Access Directive?: Yes
Actual or Planned Long-Term Data Archive Location: NCEI-CO
How Will the Data Be Protected from Accidental or Malicious Modification or Deletion Prior to Receipt by the Archive?:

Data is backed up to tape and to cloud storage.

Lineage

Lineage Statement:

The NOAA Office for Coastal Management (OCM) downloaded the GeoTiff files from the Washington Lidar Portal.

Sources

Washington Dept of Natural Resources

CC ID: 1176561
Contact Role Type: Originator
Contact Type: Organization
Contact Name: Washington Dept of Natural Resources
Citation URL: https://lidarportal.dnr.wa.gov/
Citation URL Name: Washington Lidar Portal

Process Steps

Process Step 1

CC ID: 1176562
Description:

Planning:

In preparation for data collection, QSI reviewed the project area and developed a specialized flight plan to ensure complete coverage of the Green River Watershed LiDAR study area at the target point density greater than or equal to 8.0 points/m2 (0.74 points/ft2). Acquisition parameters including orientation relative to terrain, flight altitude, pulse rate, scan angle, and ground speed were adapted to optimize flight paths and flight times while meeting all contract specifications.

Factors such as satellite constellation availability and weather windows must be considered during the planning stage. Any weather hazards or conditions affecting the flights were continuously monitored due to their potential impact on the daily success of airborne and ground operations. In addition, logistical considerations including private property access and potential air space restrictions were reviewed.

Process Step 2

CC ID: 1176563
Description:

Ground Survey Points

Ground control surveys, including base stations and ground survey points (GSPs) were conducted to support the airborne acquisition. Ground control data were used to geospatially correct the aircraft positional coordinate data and to perform quality assurance checks on final LiDAR data.

Base Stations

A combination of Washington State Reference Network (WSRN) Real-Time Network (RTN) base stations and a QSI-established monument were utilized for the Green River Watershed LiDAR project. Base stations were used to correct the flightline positional coordinate data, while QSI's monument was used to support collection of ground survey points using real time kinematic (RTK) and fast static (FS) survey techniques. QSI utilized seven existing base stations and established one new monument for the Green River Watershed LiDAR project. New monumentation was set using a 6-inch PK nail with a reference washer. QSI's professional land surveyor, Evon Silvia (WAPLS#53957) oversaw and certified the establishment of all monuments.

QSI utilized static Global Navigation Satellite System (GNSS) data collected at 1 Hz recording frequency for each base station. During post-processing, the static GNSS data were triangulated with nearby Continuously Operating Reference Stations (CORS) using the Online Positioning User Service (OPUS1) for precise positioning. Multiple independent sessions over the same monument were processed to confirm antenna height measurements and to refine position accuracy.

Ground survey points were collected using real time kinematic (RTK) and fast-static (FS) survey techniques. For RTK surveys, a roving receiver receives corrections from a nearby base station or Real-Time Network (RTN) via radio or cellular network, enabling rapid collection of points with relative errors less than 1.5 cm horizontal and 2.0 cm vertical. FS surveys compute these corrections during post-processing to achieve comparable accuracy. RTK surveys record data while stationary for at least five seconds, calculating the position using at least three one-second epochs. FS surveys record observations for up to fifteen minutes on each GSP in order to support longer baselines. All GSP measurements were made during periods with a Position Dilution of Precision (PDOP) of less than or equal to 3.0 with at least six satellites in view of the stationary and roving receivers.

GSPs were collected in areas where good satellite visibility was achieved on paved roads and other hard surfaces such as gravel or packed dirt roads. GSP measurements were not taken on highly reflective surfaces such as center line stripes or lane markings on roads due to the increased noise seen in the laser returns over these surfaces. GSPs were collected within as many flightlines as possible; however, the distribution of GSPs depended on ground access constraints and monument locations and may not be equitably distributed throughout the study area.

Process Step 3

CC ID: 1176564
Description:

Airborne Survey

The 2018 LiDAR survey was accomplished using a Riegl VQ-1560i sensor system mounted in a Cessna Caravan. Additionally, a portion of the Green River Watershed LiDAR dataset was collected with a Leica ALS80 sensor system on December 10th, 2017. Settings were used to yield an average pulse density of greater than or equal to 8 pulses/m2 over the Green River Watershed project area. The Riegl laser system records unlimited range measurements (returns) per pulse; however, it is not uncommon for some types of surfaces (e.g., dense vegetation or water) to return fewer pulses to the LiDAR sensor than the laser originally emitted. The discrepancy between first return and overall delivered density will vary depending on terrain, land cover, and the prevalence of water bodies. All discernible laser returns were processed for the output dataset.

All areas were surveyed with an opposing flight line side-lap of greater than or equal to 50% (greater than or equal to 100% overlap) in order to reduce laser shadowing and increase surface laser painting. To accurately solve for laser point position (geographic coordinates x, y and z), the positional coordinates of the airborne sensor and the attitude of the aircraft were recorded continuously throughout the LiDAR data collection mission. Position of the aircraft was measured twice per second (2 Hz) by an onboard differential GPS unit, and 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 and sensor position and attitude data are indexed by GPS time.

Process Step 4

CC ID: 1176565
Description:

Upon completion of data acquisition, QSI processing staff initiated a suite of automated and manual techniques to process the data into the requested deliverables. Processing tasks included GPS control computations, smoothed best estimate trajectory (SBET) calculations, kinematic corrections, calculation of laser point position, sensor and data calibration for optimal relative and absolute accuracy, and LiDAR point classification. Processing methodologies were tailored for the landscape.

Lidar Processing Steps

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 sensor head position and attitude recorded throughout the survey. Software used - Waypoint Inertial Explorer v.8.7

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 v. 1.4) format. Convert data to orthometric elevations by applying a geoid correction. Software used - Waypoint Inertial Explorer v.8.7 Leica CloudPro v. 1.2.4

Import raw laser points into manageable blocks to perform manual relative accuracy calibration and filter erroneous points. Classify ground points for individual flight lines. Software used - TerraScan v.18

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. Software used - TerraMatch v.18

Classify resulting data to ground and other client designated ASPRS classifications. Assess statistical absolute accuracy via direct comparisons of ground classified points to ground control survey data. Software used - TerraScan v.18, TerraModeler v.18

Generate bare earth models as triangulated surfaces. Generate highest hit models as a surface expression of all classified points. Export all surface models as ESRI GRIDs at the required pixel resolution. Software used - TerraScan v.18, TerraModeler v.18, ArcMap v. 10.3.1

Generate stream network and required hydro enforcement lines from LiDAR bare earth models. Software used - ArcHydro 2.0

Process Step 5

CC ID: 1176566
Description:

The NOAA Office for Coastal Management (OCM) downloaded 15 raster DEM files in GeoTiff format from the Washington Lidar Portal. The data were in Washington State Plane South NAD83(HARN), US survey feet coordinates and NAVD88 (Geoid12B) elevations in feet. The bare earth raster files were at a 3 feet grid spacing. No metadata record was provided with the data. This record is populated with information from the Quantum Geospatial, Inc. technical report downloaded from the Washington Dept. of Natural Resources Washington Lidar Portal.

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

1. Used internal an script to assign the EPSG codes (Horizontal EPSG: 2927 and Vertical EPSG: 6360) to the GeoTiff formatted files.

2. Copied the files to https.

Process Date/Time: 2022-06-20 00:00:00
Process Contact: Office for Coastal Management (OCM)

Related Items

Item Type Relationship Type Title
Data Set (DS) Cross Reference 2018 WA DNR Lidar: Green River Watershed, WA

Catalog Details

Catalog Item ID: 67440
GUID: gov.noaa.nmfs.inport:67440
Metadata Record Created By: Rebecca Mataosky
Metadata Record Created: 2022-06-20 18:48+0000
Metadata Record Last Modified By: Rebecca Mataosky
Metadata Record Last Modified: 2022-10-05 13:54+0000
Metadata Record Published: 2022-06-20
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2022-06-20
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2023-06-20