Evaluation of a single-beam sonar system to map seagrass at two sites in northern Puget Sound

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Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: Stevens, A.W., Lacy, J.R., Finlayson, D.P., and Gelfenbaum, G.
Publication_Date: 2008
Title:
Evaluation of a single-beam sonar system to map seagrass at two sites in northern Puget Sound
Geospatial_Data_Presentation_Form: tabular digital data
Larger_Work_Citation:
Citation_Information:
Originator: Stevens, A.W., Lacy, J.R., Finlayson, D.P., and Gelfenbaum, G.
Publication_Date: 2008
Title:
Evaluation of a single-beam sonar system to map seagrass at two sites in northern Puget Sound
Series_Information:
Series_Name: Scientific Investigations Report
Issue_Identification: 2008-5009
Publication_Information:
Publication_Place: Menlo Park, CA
Publisher: U.S. Geological Survey, Coastal and Marine Geology Program
Online_Linkage: <http://pubs.usgs.gov/sir/2008/5009/>
Description:
Abstract:
Nearshore bathymetry and seagrass cover at two sites in northern Puget Sound were mapped with single-beam sonar and an underwater video. Acoustic data were compared against underwater video data collected simultaneously to better understand the accuracy, limitations and benefits of mapping seagrass acoustically in Puget Sound.
Purpose:
The goal of the project was two-fold: 1) To quantify eelgrass (Z. marina) habitat at two sites, Possession Point and Browns Bay, in northern Puget Sound and 2) Evaluate the benefits and limitations of using acoustics, specifically single-beam sonar, to map seagrass in Puget Sound.
Supplemental_Information:
To map seagrass at two sites in northern Puget Sound, a dual-frequency Biosonics sonar operating at 200 and 430 kHz was used to map seafloor depth, morphology and vegetation. An underwater video camera was deployed to ground-truth acoustic data. Fifty one sediment samples were collected to quantify sediment grain size distributions across Possession Point. Sediment samples were analyzed for grain size at the Western Coastal and Marine Geology Team sediment laboratory in Menlo Park, CA.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20070130
Ending_Date: 20070202
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -123.17290
East_Bounding_Coordinate: -123.13793
North_Bounding_Coordinate: 48.60642
South_Bounding_Coordinate: 48.58775
Keywords:
Theme:
Theme_Keyword_Thesaurus: General
Theme_Keyword: U.S. Geological Survey
Theme_Keyword: USGS
Theme_Keyword: Coastal and Marine Geology Program
Theme_Keyword: CMGP
Theme_Keyword: bathymetry
Theme_Keyword: seagrass
Theme_Keyword: sediment
Theme_Keyword: oceans and estuaries
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: geoscientificinformation
Theme_Keyword: location
Theme_Keyword: oceans
Theme_Keyword: inlandWaters
Theme_Keyword: elevation
Theme:
Theme_Keyword_Thesaurus: Global Change Master Directory (GCMD)
Theme_Keyword: Earth Science > Oceans > Bathymetry/Seafloor Topography
Theme_Keyword: Earth Science > Oceans > Coastal Processes
Theme_Keyword: Earth Science > Oceans > Marine Sediments
Theme_Keyword: Instruments > Grab Samplers
Place:
Place_Keyword_Thesaurus: General
Place_Keyword: WA
Place_Keyword: USA
Place:
Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)
Place_Keyword: Possession Point
Place_Keyword: Browns Bay
Place_Keyword: Puget Sound
Place_Keyword: Washington
Access_Constraints: None
Use_Constraints:
Public domain data from the U.S. government is freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS) as the source of this information.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Andrew Stevens
Contact_Organization: U.S. Geological Survey, Coastal and Marine Geology
Contact_Position: Oceanographer
Contact_Address:
Address_Type: mailing and physical address
Address: 345 Middlefield R. MS999
City: Menlo Park
State_or_Province: CA
Postal_Code: 94025-3561
Country: USA
Contact_Voice_Telephone: (650) 329-5243
Contact_Facsimile_Telephone: (650) 329-5190
Contact_Electronic_Mail_Address: astevens@usgs.gov
Browse_Graphic:
Browse_Graphic_File_Name:
<http://walrus.wr.usgs.gov/infobank/b/b207ps/html/b-2-07-ps.meta.html>
Browse_Graphic_File_Description: Index map of field activity B-2-07-PS.
Browse_Graphic_File_Type: GIF
Cross_Reference:
Citation_Information:
Originator: U.S. Geological Survey, Coastal and Marine Geology Program
Publication_Date: 2007
Title: InfoBank
Online_Linkage:
<http://walrus.wr.usgs.gov/infobank/b/b207ps/html/b-2-07-ps.meta.html>


Data_Quality_Information:
Logical_Consistency_Report:
A) Bathymetric mapping

Completeness_Report:
A) Bathymetric mapping

Sixty (60) kilometers of acoustic bathymetry/substrate data were collected with a dual-frequency (200 and 430 kHz) Biosonics system along 163 transects in Possession Point between 1/30/07 and 2/1/07. Eighteen(18) kilometers of acoustic bathymetry/substrate data were collected with the same system along 65 transects in Browns Bay on 2/2/2007. The Biosonics sonar generates a 6-degree cone of sound, which translates into a footprint on the seafloor ranging 0.55 to 55 m^2 area for the water depths surveyed (2 - 20 m). Ship speed generally ranged 4.0-4.5 kts and data were merged with GPS positions at 1 Hz. Track lines were spaced 25 - 50 m apart.

B) Sediment Samples for Grain Size Analyses

Sediment samples were collected using a van veen grab sampler or taken directly during low-tide surveys.

In the field, a sub-sample of the uppermost 1-3 cm of each grab was collected and placed into storage bags, labeled, and logged.

Samples were disaggregated and sieved through 2000 and 62 micron screens to separate gravel, sands and mud after the organic component was removed by treatment with hydrogen peroxide. Sediment grain size of sands was determined using the settling methods and principles of Stokes Law on the USGS 3-m long settling tubes. The fine fraction (silts and clays) were analyzed on a Coulter 230 Laser Particle Analyzer. Three samples had less than 3% intermediate fraction and were analyzed on the Coulter. Single sample runs were made on the tubes, while results from the laser particle analyzer are averages of triplicates with standard deviations around the mean ranging 18 to 24 microns due to instrument errors.

Lineage:
Process_Step:
Process_Description:
A) Bathymetric mapping

The combined bathymetric data were merged to create a digital elevation model representing the surface topography of Possession Point and Browns Bay. This surface is referenced to the NAD83 datum in the WA State Plane North, meters projection with a horizontal accuracy of 2.3 cm. Elevations are referenced to NAVD88 with an estimated vertical accuracy ranging 2.6-9.8 cm. This includes error from the RTK-DGPS and Biosonics sonar, and errors introduced in data processing.

Process_Date: 2007
Process_Step:
Process_Description:
B) Sediment Samples for Grain Size Analyses

Results from the tubes and laser particle analyzer were merged using standard USGS methods found in the USGS particle analysis program pcSedSize.

Process_Date: 2007


Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Point


Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Geographic:
Latitude_Resolution: 0.00001
Longitude_Resolution: 0.00001
Geographic_Coordinate_Units: Decimal degrees
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257222
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:
Altitude_Datum_Name: North American Vertical Datum of 1988
Altitude_Resolution: 0.1
Altitude_Distance_Units: meters
Altitude_Encoding_Method:
Explicit elevation coordinate included with horizontal coordinates
Depth_System_Definition:
Depth_Datum_Name: local surface
Depth_Resolution: 0.1
Depth_Distance_Units: meters
Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates


Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: line[number].xyz
Entity_Type_Definition: digital surface elevation data
Entity_Type_Definition_Source: USGS
Attribute:
Attribute_Label: X
Attribute_Definition: Location X-coordinate of the data point.
Attribute_Definition_Source: USGS
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 486997.617
Range_Domain_Maximum: 489962.263
Attribute_Units_of_Measure: meters
Attribute_Measurement_Resolution: 0.001
Attribute:
Attribute_Label: Y
Attribute_Definition: Location Y-coordinate of the data point.
Attribute_Definition_Source: USGS
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 5381456.319
Range_Domain_Maximum: 5383932.558
Attribute_Units_of_Measure: meters
Attribute_Measurement_Resolution: 0.001
Attribute:
Attribute_Label: Z
Attribute_Definition: Location Z-coordinate of the data point.
Attribute_Definition_Source: USGS
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -10.00
Range_Domain_Maximum: 0.00
Attribute_Units_of_Measure: meters
Attribute_Measurement_Resolution: 0.01
Detailed_Description:
Entity_Type:
Entity_Type_Label: sediment grain size data
Entity_Type_Definition: surface elevation data
Entity_Type_Definition_Source: USGS
Attribute:
Attribute_Label: Lon
Attribute_Definition: Location X-coordinate of the data point.
Attribute_Definition_Source: USGS
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -123.58611
Range_Domain_Maximum: -123.13611
Attribute_Units_of_Measure: decimal degrees
Attribute_Measurement_Resolution: 0.00001
Attribute:
Attribute_Label: Lat
Attribute_Definition: Location Y-coordinate of the data point.
Attribute_Definition_Source: USGS
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 48.58611
Range_Domain_Maximum: 48.60833
Attribute_Units_of_Measure: decimal degrees
Attribute_Measurement_Resolution: 0.00001
Attribute:
Attribute_Label: Depth_m
Attribute_Definition: Location Z-coordinate of the data point.
Attribute_Definition_Source: USGS
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.00
Range_Domain_Maximum: 10.00
Attribute_Units_of_Measure: meters
Attribute_Measurement_Resolution: 0.01
Overview_Description:
Entity_and_Attribute_Overview:
Sample of digital surface elevation data XYZ ASCII file, bathy/line95.xyz:
X             Y              Z
487989.879521 5381998.198351 -3.31
487990.116289 5381998.892258 -3.34
487989.943243 5382001.029467 -3.40

Sample of sediment sampling log:
Station Local_Time       UTC           Lon             Lat           Depth_m    Comment
1    6/1/07 20:44    6/2/07    3:44    -123.1430877    48.60642247    2.286     -
2    6/1/07 20:35    6/2/07    3:35    -123.1416559    48.60596625    2.1336    18.6 C
3    6/1/07 20:28    6/2/07    3:28    -123.1396819    48.60476647    2.4384    22.4 C
Entity_and_Attribute_Detail_Citation: none


Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey, Coastal and Marine Geology
Contact_Person: Andrew Stevens
Contact_Position: Oceanographer
Contact_Address:
Address_Type: mailing and physical address
Address: 345 Middlefield Rd. MS999
City: Menlo Park
State_or_Province: CA
Postal_Code: 94025-3561
Country: USA
Contact_Voice_Telephone: (650) 329-5243
Contact_Facsimile_Telephone: (650) 329-5190
Contact_Electronic_Mail_Address: astevens@usgs.gov
Distribution_Liability:
Although this data set has been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials.

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.


Metadata_Reference_Information:
Metadata_Date: 20080212
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey, Coastal and Marine Geology
Contact_Person: Andrew Stevens
Contact_Position: Oceanographer
Contact_Address:
Address_Type: mailing and physical address
Address: 345 Middlefield Rd. MS999
City: Menlo Park
State_or_Province: CA
Postal_Code: 94025-3561
Country: USA
Contact_Voice_Telephone: (650) 329-5243
Contact_Facsimile_Telephone: (650) 329-5190
Contact_Electronic_Mail_Address: astevens@usgs.gov
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998

Generated by mp version 2.8.11 on Tue Feb 12 13:38:16 2008