Topography data from the Elwha River delta, Washington, August 2022

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Metadata:

Identification_Information
Data_Quality_Information
Spatial_Data_Organization_Information
Spatial_Reference_Information
Entity_and_Attribute_Information
Distribution_Information
Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: Andrew W. Stevens
Originator: Guy R. Gelfenbaum
Originator: Jonathan A. Warrick
Originator: Ian M. Miller
Originator: Heather M. Weiner
Publication_Date: 20230522
Title:

Topography data from the Elwha River delta, Washington, August 2022

Geospatial_Data_Presentation_Form: comma-delimited text
Series_Information:

Series_Name: data release
Issue_Identification: DOI:10.5066/P9N7N9P0

Publication_Information:

Publication_Place:

Pacific Coastal and Marine Science Center, Santa Cruz, California

Publisher: U.S. Geological Survey

Online_Linkage: https://doi.org/10.5066/P9N7N9P0
Online_Linkage:

https://www.sciencebase.gov/catalog/file/get/6171e1bad34ea36449a86d6b

Larger_Work_Citation:

Citation_Information:

Originator: Andrew W. Stevens
Originator: Guy R. Gelfenbaum
Originator: Jonathan A. Warrick
Originator: Ian M. Miller
Originator: Heather M. Weiner
Publication_Date: 2023
Title:

Bathymetry, topography, and sediment grain-size data from the Elwha River delta, Washington, August 2022

Series_Information:

Series_Name: data release
Issue_Identification: DOI:10.5066/P9N7N9P0

Publication_Information:

Publication_Place: Pacific Coastal and Marine Science Center, Santa Cruz, CA
Publisher: U.S. Geological Survey

Other_Citation_Details:

Stevens, A.W., Gelfenbaum, G.R., Warrick, J.A., Miller, I.M., and Weiner, H.M., 2023, Bathymetry, topography, and sediment grain-size data from the Elwha River delta, Washington, August 2022: U.S. Geological Survey data release, https://doi.org/10.5066/P9N7N9P0.

Online_Linkage: https://doi.org/10.5066/P9N7N9P0

Description:

Abstract:

This part of the data release presents topography data from the Elwha River delta collected in August 2022. Topography data were collected on foot with global navigation satellite system (GNSS) receivers mounted on backpacks.

Purpose:

Data were obtained to assess the coastal geomorphic response following the removal of two dams on the Elwha River. These data are intended for science researchers, students, policy makers, and the general public. These data can be used with geographic information systems or other software to identify topographic and shallow-water bathymetric features.

Supplemental_Information:

Additional information about the field activities from which these data were derived is available online at:
https://cmgds.marine.usgs.gov/fan_info.php?fan=2022-638-FA
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20220809
Ending_Date: 20220811

Currentness_Reference: Ground condition at time data were collected

Status:

Progress: Complete
Maintenance_and_Update_Frequency: None planned

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -123.5879121
East_Bounding_Coordinate: -123.4720889
North_Bounding_Coordinate: 48.1513719
South_Bounding_Coordinate: 48.1317098

Keywords:

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: elevation

Theme:

Theme_Keyword_Thesaurus: Data Categories for Marine Planning
Theme_Keyword: Bathymetry and Elevation

Theme:

Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: topography
Theme_Keyword: GPS measurement

Theme:

Theme_Keyword_Thesaurus: Marine Realms Information Bank (MRIB) keywords
Theme_Keyword: Global Positioning System (GPS) observations

Theme:

Theme_Keyword_Thesaurus: None
Theme_Keyword: U.S. Geological Survey
Theme_Keyword: USGS
Theme_Keyword: Coastal and Marine Hazards and Resources Program
Theme_Keyword: CMHRP
Theme_Keyword: Pacific Coastal and Marine Science Center
Theme_Keyword: PCMSC

Theme:

Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword: USGS:6418cb68d34eb496d1d1d715

Place:

Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)
Place_Keyword: Clallam County
Place_Keyword: Olympic Peninsula
Place_Keyword: Strait of Juan de Fuca
Place_Keyword: Elwha River

Access_Constraints: None
Use_Constraints:

USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data. This information is not intended for navigation purposes.

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

U.S. Geological Survey, Pacific Coastal and Marine Science Center

Contact_Person: PCMSC Science Data Coordinator

Contact_Address:

Address_Type: mailing and physical
Address: 2885 Mission Street
City: Santa Cruz
State_or_Province: CA
Postal_Code: 95060

Contact_Voice_Telephone: 831-427-4747
Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov

Native_Data_Set_Environment: MATLAB Version: 9.8.0.1396136 (R2020a)

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report: No formal attribute accuracy tests were conducted.

Logical_Consistency_Report: No formal logical accuracy tests were conducted.
Completeness_Report:

Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

A series of benchmarks with known coordinates were established adjacent to the study area to provide geodetic control for the bathymetric and topographic surveys. The positions of the benchmarks were derived from a minimum of two static GNSS occupations. The equipment for the static occupations consisted of a dual frequency GNSS receiver, a fixed-height tripod, and antenna. The static observations were recorded internally in the receiver and the raw observations were processed using the National Geodetic Survey (NGS) Online Positioning User Service (OPUS, https://www.ngs.noaa.gov/OPUS/). Estimated uncertainties in the horizontal position of the individual GNSS occupations were provided by OPUS and ranged between 0.006 m and 0.06 m with an average horizontal uncertainty of 0.02 m. The processed positions from each occupation were averaged to obtain the final reported position of the benchmark. All final positions of the GNSS backpacks were determined using differential corrections from the base station receivers. Manufacturer reported accuracy for the differentially corrected horizontal positions for the rover receivers used in the survey is 0.8 cm + 0.5 ppm. Baselines from the GNSS base station were typically less than 5 km, suggesting a horizontal accuracy of backpack positions to be 0.825 cm relative to the base station. The combined horizontal uncertainty from the base station coordinate solutions and rover trajectories is therefore approximately 3 cm. Uncertainty in the horizontal positions associated with variable posture during data collection of the surveyors is unknown.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

The vertical uncertainty of topographic measurements is estimated by combining the uncertainty in the base station coordinate and remote GNSS positions collected in kinematic mode. Uncertainties in the elevation of the base station were provided by NGS OPUS and ranged between 0.02 m and 0.04 m, with an average vertical uncertainty of 0.03 m. Manufacturer reported vertical accuracy in the rover positions is 1.5 cm + 1 ppm for differential corrected kinematic data for the rover receivers used in the surveys. Baseline lengths were typically less than 5 km, suggesting the vertical accuracy of backpack positions to be 2 cm relative to the base station coordinates. Combining the uncertainty in the elevation of the base station coordinates and rover positions yields a total uncertainty in the backpack GNSS positions of approximately 5 cm. Uncertainty in the vertical positions associated with variable posture of the surveyors during data collection is unknown.

Lineage:

Process_Step:

Process_Description:

Topographic data were collected between August 9 and August 11, 2022, on foot with GNSS equipment mounted on backpacks operating primarily in real-time kinematic (RTK) mode. GNSS backpacks were equipped with a dual-frequency GNSS receivers and handheld data collectors. Differential corrections were transmitted at 1-Hz intervals by a VHF radio to the backpack GNSS receivers from a GNSS base station placed on a benchmark with known horizontal and vertical coordinates relative to the North American Datum of 1983 (CORS96 realization) and North American Vertical Datum of 1988. Prior to data collection, vertical distances between the GNSS antenna and the ground were measured using a tape measure for each topographic surveyor. Hand-held data collectors were used to log raw data and display navigational information allowing surveyors to navigate along predefined survey lines spaced at 25- to 50-m intervals along the delta. Profiles were surveyed from the landward edge of the primary dune over the beach foreshore, to wading depth on the same series of transects as the nearshore bathymetry platforms. Additional topography data between transects were collected to better characterize morphologic variability within the study area.

Process_Date: 20220811

Process_Step:

Process_Description:

Raw topography data were reviewed in Trimble Business Center (TBC) to ensure measured antenna offsets were applied properly in the field. Differential post-processing was performed on points collected in autonomous mode where VHF communication with the base station failed. Orthometric elevations relative to the NAVD88 vertical datum were computed assuming a static geoid value of -20.11 m which is based on the NGS Geoid09 offset at the location of the GNSS base stations. The final point data are projected in cartesian coordinates using the Washington State Plane North, meters coordinate system.

Process_Date: 20220919

Process_Step:

Process_Description:

All available topographic data from the survey were compiled into a comma-delimited text file for distribution

Process_Date: 20230317

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Point
Point_and_Vector_Object_Information:

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: Point
Point_and_Vector_Object_Count: 211811

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Geographic:

Latitude_Resolution: 0.0000001
Longitude_Resolution: 0.0000001
Geographic_Coordinate_Units: Decimal degrees

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: GRS_1980
Semi-major_Axis: 6378137.0
Denominator_of_Flattening_Ratio: 298.257222101

Vertical_Coordinate_System_Definition:

Altitude_System_Definition:

Altitude_Datum_Name: North American Vertical Datum of 1988
Altitude_Resolution: 0.01
Altitude_Distance_Units: meters
Altitude_Encoding_Method:

Explicit elevation coordinate included with horizontal coordinates

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: Attribute Table
Entity_Type_Definition:

Table containing attribute information associated with the dataset

Entity_Type_Definition_Source: Producer defined

Attribute:

Attribute_Label: datetime_utc
Attribute_Definition:

The date and time of data collection in Coordinated Universal Time (UTC).