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Short Citation:
OCM Partners, 2023: 2012 OLC Bathymetric Lidar DEM: Sandy River (OR), https://www.fisheries.noaa.gov/inport/item/56855.

Item Identification

Title: 2012 OLC Bathymetric Lidar DEM: Sandy River (OR)
Short Name: or2012 sandy river bathy dem m8696
Status: Completed
Creation Date: 2012
Publication Date: 2012
Abstract:

Airborne topobathymetric lidar point cloud collected for the Sandy River, Oregon in 2012.

The Sandy River flows through areas of steep terrain and dense tree canopy and is home to Chinook and Coho salmon and Steelhead trout. The Sandy River is further distinguished by the 2007 removal of the Marmot Dam (river mile 30) and has been the focus of ongoing monitoring to understand the impacts of dam removal on downstream morphology and fish habitat. The nature of the river makes it challenging for traditional transect or boat-based bathymetric surveys.

Purpose:

The data were collected to map channel and floodplain morphology and to evaluate the effectiveness of new topo-bathymetric LiDAR technology in a Pacific Northwest riverine environment. The project was conducted through the Oregon LiDAR Consortium (OLC) with contributions from DOGAMI, the Federal Emergency Management Agency (FEMA), and the Bureau of Land Management (BLM).

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 > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > SEAFLOOR TOPOGRAPHY
ISO 19115 Topic Category
elevation
UNCONTROLLED
None Oregon

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
VERTICAL LOCATION > LAND SURFACE

Instrument Keywords

Thesaurus Keyword
UNCONTROLLED
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

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: As Needed
Data Presentation Form: Model (digital)
Entity Attribute Overview:

Point cloud with points classified as unclassified (1) or ground (2)

Data Set Credit: Oregon Lidar Consortium; Watershed Sciences, Inc; DOGAMI; FEMA; BLM

Support Roles

Data Steward

CC ID: 860211
Date Effective From: 2019-03-22
Date Effective To:
Contact (Organization): Office for Coastal Management (OCM)
Address: 2234 South Hobson Avenue
Charleston, SC 29405-2413
URL: https://www.coast.noaa.gov/

Distributor

CC ID: 860210
Date Effective From: 2019-03-21
Date Effective To:
Contact (Organization): Office for Coastal Management (OCM)
Address: 2234 South Hobson Avenue
Charleston, SC 29405-2413
URL: https://www.coast.noaa.gov/

Metadata Contact

CC ID: 860212
Date Effective From: 2019-03-22
Date Effective To:
Contact (Organization): Office for Coastal Management (OCM)
Address: 2234 South Hobson Avenue
Charleston, SC 29405-2413
URL: https://www.coast.noaa.gov/

Extents

Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1152625
W° Bound: -122.410523
E° Bound: -121.934087
N° Bound: 45.57894
S° Bound: 45.336942
Description

Area includes the Sandy River and a buffer of land around it.

Extent Group 1 / Vertical Extent 1

CC ID: 1152626
CRS Type: Vertical
EPSG Code: EPSG:5703
EPSG Name: NAVD88 height
See Full Coordinate Reference System Information
Vertical Minimum: 0.0
Vertical Maximum: 860.0

Extent Group 1 / Time Frame 1

CC ID: 1152624
Time Frame Type: Discrete
Start: 2012-09-22

Spatial Information

Reference Systems

Reference System 1

CC ID: 1152622

Coordinate Reference System

CRS Type: Projected
EPSG Code: EPSG:3717
EPSG Name: NAD83(NSRS2007) / UTM zone 10N
See Full Coordinate Reference System Information

Access Information

Security Class: Unclassified
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: 860213
Start Date: 2019-03-21
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8696
Distributor: Office for Coastal Management (OCM) (2019-03-21 - Present)
Description:

Application to 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.

File Type: Multiple formats
Compression: Zip

Distribution 2

CC ID: 860214
Start Date: 2019-03-21
End Date: Present
Download URL: https://coast.noaa.gov/htdata/raster2/elevation/OLC_sandy_river_dem_2012_8696
Distributor: Office for Coastal Management (OCM) (2019-03-21 - Present)
Description:

Bulk download of data files in GeoTiff format,

File Type: GeoTIFF

URLs

URL 1

CC ID: 860215
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/8694/supplemental/Sandy_River_LiDAR_final.pdf
Name: Data set report
URL Type:
Online Resource
File Resource Format: pdf
Description:

Report by WSI that formed the basis for this metadata. Contains additional information.

URL 2

CC ID: 860216
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/8694/supplemental/2012_sandy_river_m8694.kmz
Name: Data set extent
URL Type:
Browse Graphic
File Resource Format: kmz
Description:

graphic showing the extent of the data set.

Data Quality

Vertical Positional Accuracy:

Bare earth topography: 0.060 meters at 95% confidence

High confidence bathymetry areas: 0.347 meters at 95% confidence

Low confidence bathymetry areas: 0.779 meters at 95% confidence

Low confidence areas have a low point density. See report for details.

Lineage

Lineage Statement:

Lidar was flown from two instruments over the Sandy River in Oregon. Data were processed to point clouds and classified as ground or unclassified.

Sources

DEM files

CC ID: 1152615
Contact Role Type: Originator
Contact Type: Organization
Contact Name: Watershed Sciences Inc

Process Steps

Process Step 1

CC ID: 1152616
Description:

Planning:

The airborne survey was designed to collect a point density of 4-5 pulses/m2 for the topo-bathymetric LiDAR. The flight was planned with a scan angle of ±20o and 50% side-lap. The 50% side-lap was used to ensure uniform coverage and to minimize laser shadowing due to vegetation and terrain. The flights were conducted in the late fall during base flow conditions to maximize water clarity and ensure shallow depths (Figure 2).

The flight lines were developed using ALTM-NAV Planner (v.3.0) software and Leica Mission Pro Flight Planning and Evaluation (FPES) software. Efforts were taken to optimize flight paths by minimizing flight times while meeting all accuracy specifications. The WSI acquisition staff considered all factors such as air space restrictions, private property access, and GPS quality in the planning of this mission.

Process Date/Time: 2012-01-01 00:00:00

Process Step 2

CC ID: 1152617
Description:

Lidar Survey:

Two lidar instruments were flown. A Riegel VQ-820-Q for bathymetric collection and a Lieca ALS60 for topographic collection.

The Riegl VQ-820-G uses a green-wavelength (μ = 532 nm) laser that, in addition to collecting vegetation and topography data, is able to penetrate the water surface with the 532-nm wavelength which provides for minimal spectral absorption. The sensor also collects both discrete returns (similar to the NIR data) and full-waveform data (every other pulse) for more rigorous feature extraction and evaluation of point returns. The recorded waveform enables range measurements for all discernible targets for a given pulse. The typical number of returns digitized from a single pulse ranged from 1 to 7 for the Sandy River project area.

The Leica ALS60 uses a NIR wavelength (μ =1,064nm) laser that has been proven to provide high value terrestrial topography data. The NIR wavelengths do not penetrate the water column and thus provide water surface returns for received pulses off of water surface. The Leica system collects 8-bit intensity information and does not store waveform information.

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. 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.

Process Date/Time: 2012-01-01 00:00:00

Process Step 3

CC ID: 1152618
Description:

Lidar Processing:

Prior to the mission, a boresight calibration flight was conducted in Corvallis, OR and processed by WSI to ensure accurate initial sensor alignment. An individual mission calibration was also performed on the Sandy River data set using Riegl’s RiProcess software. RiProcess was then used by WSI to further refine line-to-line calibration of the topo-bathymetric LiDAR dataset to match collected hard surface RTK control points.

Upon completion of calibration, Dewberry processed the LiDAR returns with a combination of manual and automated techniques using both the Riegl software and in-house proprietary software to differentiate the bathymetric and terrestrial data. WSI processed NIR LiDAR and the orthorectified digital imagery, which were also used to facilitate the processing of the bathymetric returns. Once bathymetric points were differentiated, they were spatially corrected for refraction through the water column based on the angle of incidence of the laser. Dewberry refracted water column points and classified the resulting point cloud. The resulting data was sent back to WSI for further review and product creation. Figure 4 shows the various datasets used in the bathymetric analysis while Table 7 summarizes the steps used to process the bathymetric LiDAR data.

Process Date/Time: 2012-01-01 00:00:00

Process Step 4

CC ID: 1152619
Description:

Point Classification:

As with standard NIR LiDAR data, bathymetric (green) LiDAR returns are classified into categories according to whether the points are considered above ground, ground, or water. Additional LiDAR classifications were created for bathymetric processing by adding categories for channel bottom, water surface, and water column points.

Process Date/Time: 2012-01-01 00:00:00

Process Step 5

CC ID: 1152620
Description:

Full Waveform Processing:

Initial echo analysis is accomplished with Riegl’s online waveform processing. In online waveform processing, discrete returns are digitized from the echo signal based on the amplitude and pulse deviation of returning energy. To facilitate discrimination of ground points versus water column points and bathymetry points, the Riegl VQ-820-G uses the online waveform processing system that generates a discrete point cloud dataset at time of capture (“online”) from the full waveform signal. The system also records geo-referenced waveforms for a subsample of the data (configured for every other pulse). The waveforms are used in determining accurate bathymetry in shallow submerged environments. The separation of the water surface and bottom return in shallow depths requires further analysis and customized methods to ‘decompose’ or ‘deconvolve’ the waveform.

Furthermore, certain parameters such as attenuation coefficients need to be set when processing data in various depth ranges and water column parameters. Information derived from the waveforms is used to set these parameters. The determination of the bottom return also needs to be corrected for the change in speed of light through the water column and the refraction of light at the air/water interface. The processed waveforms are used to validate the online digitization of the initial point cloud data.

Process Date/Time: 2012-01-01 00:00:00

Process Step 6

CC ID: 1152621
Description:

The NOAA Office for Coastal Management received the lidar data from the Oregon Lidar Consortium. There were two sets of DEMs, one labeled as bare earth and one labeled as topobathy. They cover the same area, but the topobathy set appears to have more noise and/or variance. Only the bare earth DEMs were kept.

The data report indicates that the data were collected and delivered in NAD83(CORS96) UTM Zone 10. The GeoTiff files indicated NAD83(HARN) UTM Zone 10. The data report is believed to be correct. The data were likely coded with HARN because there was no EPSG code for CORS96 UTM Zone 10 to use for the encoding. Note that the metadata system housing this metadata does not have either the HARN or CORS96 UTM Zone 10 codes, so the closest option (NSRS2007) was used in the metadata.

Metadata was not delivered with the data. This metadata was created from the WSI report.

Process Date/Time: 2019-03-22 00:00:00
Process Contact: Office for Coastal Management (OCM)
Source: DEM files

Related Items

Item Type Relationship Type Title
Data Set (DS) Cross Reference 2012 OLC Bathymetric Lidar: Sandy River (OR)

Point cloud used to create this data.

Catalog Details

Catalog Item ID: 56855
GUID: gov.noaa.nmfs.inport:56855
Metadata Record Created By: Kirk Waters
Metadata Record Created: 2019-07-10 06:47+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2022-08-09 17:11+0000
Metadata Record Published: 2022-03-16
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2022-03-16
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2023-03-16