Acoustic backscatter data collected in 2008 offshore Tijuana River Estuary, California, during USGS Field Activity S-5-08-SC

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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: Peter Dartnell
Originator: David P. Finlayson
Originator: Jonathan A. Warrick
Publication_Date: 2020
Title:

Acoustic backscatter data collected in 2008 offshore Tijuana River Estuary, California, during USGS Field Activity S-5-08-SC

Geospatial_Data_Presentation_Form: GeoTIFF
Series_Information:

Series_Name: data release
Issue_Identification: DOI:10.5066/P9Y8CDFI

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/P9Y8CDFI
Online_Linkage:

https://cmgds.marine.usgs.gov/data-releases/datarelease/10.5066-P9Y8CDFI/dataset/16/

Larger_Work_Citation:

Citation_Information:

Originator: Peter Dartnell
Originator: David P. Finlayson
Originator: Jonathan A. Warrick
Publication_Date: 2020
Title:

Bathymetry and acoustic backscatter data collected in 2008 offshore Tijuana River Estuary, California during USGS Field Activity S-5-08-SC

Series_Information:

Series_Name: data release
Issue_Identification: DOI:10.5066/P9Y8CDFI

Publication_Information:

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

Online_Linkage: https://doi.org/10.5066/P9Y8CDFI

Description:

Abstract:

These metadata describe acoustic backscatter data collected during a 2008 SWATHPlus-M survey offshore Tijuana River Estuary, California. Data were collected and processed by the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC) with fieldwork activity number S-5-08-SC. The acoustic backscatter data are provided as a GeoTIFF image.

Purpose:

Coastal mapping was conducted as part of the Tijuana Estuary Fine Sediment Fate and Transport Demonstration Project, which was developed by a number of State of California, Federal, and private industry partners to provide information about the directions, rates, and processes of fine sediment transport at nearshore settings of California. The primary goal of the Demonstration Project was the monitoring of the transport, fate, and impacts of fine sediment from beach sediment nourishments in 2008 and 2009 near the Tijuana River Estuary, Imperial Beach, California. To achieve this goal, the USGS monitored the water, beach, and seafloor properties near the project site. The coastal mapping described in this report provided important baseline bathymetric and seafloor substrate information for the Demonstration Project and was used to develop sampling programs for the Demonstration Project. 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 bathymetric features. These data are not intended to be used for navigation.

Supplemental_Information:

Additional information about the field activity from which these data were derived is available online at:
https://cmgds.marine.usgs.gov/fan_info.php?fan=S508SC
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in Esri format, this metadata file may include some Esri-specific terminology.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20080428
Ending_Date: 20080507

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: -123.181
East_Bounding_Coordinate: -123.126
North_Bounding_Coordinate: 32.595
South_Bounding_Coordinate: 32.534

Keywords:

Theme:

Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword: USGS:8574973d-b856-421e-8d78-988a62374037

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: geoscientificInformation
Theme_Keyword: elevation

Theme:

Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: bathymetry
Theme_Keyword: bathymetry measurement
Theme_Keyword: sea-floor characteristics
Theme_Keyword: geospatial datasets
Theme_Keyword: marine geophysics
Theme_Keyword: sonar methods

Theme:

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

Theme:

Theme_Keyword_Thesaurus: Marine Realms Information Bank (MRIB) keywords
Theme_Keyword: field observation

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

Place:

Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)
Place_Keyword: Pacific Ocean
Place_Keyword: State of California
Place_Keyword: Imperial Beach
Place_Keyword: Tijuana River National Estuarine Research Reserve

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 originators 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

Browse_Graphic:

Browse_Graphic_File_Name:

https://cmgds.marine.usgs.gov/data-releases/media/2020/10.5066-P9Y8CDFI/94117628a7a545618485bfed82da9621/Tijuana_backscatter_QV.jpg

Browse_Graphic_File_Description: Quick view image of the Tijuana River Delta backscatter data.
Browse_Graphic_File_Type: JPEG

Native_Data_Set_Environment:

Caris HIPS and SIPS (version 7.1.1 Service Pack 3) and ArcMap (ver. 10.3.1) on a Windows 7 computer.

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:

The SWATHPlus-M sonar system (234 kHz) depth accuracy reduces with horizontal range. The system has an estimated vertical depth uncertainty ranging from about 0.05 m to 0.30 m over a horizontal range of 0 to 90 m (https://www.iter-systems.com/wp-content/uploads/2020/03/ETD_2002_Bathyswath-2_Tech-info_EN.pdf). Accuracies of final products may be lower due to total propagated uncertainties of the mapping systems, which include sonar system, position and motion compensation system, and navigation, as well as data processing that includes sounding cleaning, gridding, and datum transformations.

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:

Uncertainty in the horizontal position of each sounding is a function of the total uncertainty propagated through each of the following component instruments: 1) base station GPS, 2) vessel GPS, 3) intertial motion unit (IMU), 4) water sound velocity model, and 5) beam spreading in the water column. Assuming no systematic errors in the measurement instruments themselves, beam spreading is the dominate source of positional uncertainty. The 1-degree sonar beam of the SWATHplus-M results in horizontal uncertainty ranging from 0.10 m at 10 m slant range, to about 0.45 m at 50 m slant range.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report: Not applicable to backscatter data.

Lineage:

Process_Step:

Process_Description:

Sonar Data Collection - The bathymetric surveys were conducted using a 234.5 kHz SEA (Systems Engineering & Assessment Ltd) SWATHplus-M phase-differencing sidescan sonar. The sonar was pole-mounted on the 34-foot USGS mapping vessel R/V Parke Snavely, and affixed to a hull brace. Real-time kinematic (RTK) GPS position data were passed through a CodaOctopus F180 intertial measurement unit (IMU) to the sonar hardware and data collection software. Sonar heads, GPS antennae, and the IMU were surveyed in place to a common reference frame with a Geodimeter 640 Total Station. The R/V Snavely was outfitted with three networked workstations and a navigation computer for use by the captain and survey crew for data collection and initial processing.

Process_Date: 20080429

Process_Step:

Process_Description:

Geodetic Control - Geodetic control for the survey was established using a shore based Global Positioning System (GPS) base station broadcasting Real Time Kinematic (RTK) corrections to the survey vessel via UHF radio link. The base station was located at atop the Tijuana River National Estuarine Reserve Visitor Center. The base station was programmed using the NAD83 (CORS96) reference frame with an Epoch of 2002.0000. Average Opus Solution coordinates for the station are:


Reference Frame: NAD83 (CORS96)
Epoch: 2002.0000
Latitude: N 32D 34' 29.10834"
Longitude: W 117D 7' 36.23523"
Ellipsoid Height: -25.765 m
Orthometric Height: 9.583 m (Geoid09)
UTM Zone 11 Northing: 3604152.632 m
UTM Zone 11 Easting: 488104.754 m

Reference Frame: WGS84 (G1150)
Epoch: 2008.3246
Latitude: N 32D 34' 29.12697"
Longitude: W 117D 7' 36.29008"
Ellipsoid Height: -26.526 m

Process_Date: 20080429

Process_Step:

Process_Description:

Vessel Position and Attitude - The R/V Snavely was equipped with a CodaOctopus F180 attitude and positioning system for the duration of the survey. The F180receives real-time kinematic (RTK) corrections directly. The RTK GPS data (2 cm error ellipse) are combined with the inertial motion measurements directly within the F180 hardware so that high-precision position and attitude corrections are fed in real-time to the sonar acquisition equipment. The NAD83 (CORS96) Epoch 2002.0000 3-dimensional reference frame was used for all data acquisition.

Process_Date: 20080429

Process_Step:

Process_Description:

Sound Velocity Measurements - Sound velocity measurements were collected continuously with an Applied Micro Systems Micro SV deployed on the transducer frame for real-time sound velocity adjustments at the transducer-water interface. The Micro SV is accurate to +/- 0.03 m/s. In addition, sound velocity profiles (SVP) were collected with an Applied Micro Systems, SvPlus 3472. This instrument provides time-of-flight sound-velocity measurements by using invar rods with a sound-velocity accuracy of about 0.06 m/s, pressure measured by a semiconductor bridge strain gauge to an accuracy of 0.15 percent (Full Scale) and temperature measured by thermistor to an accuracy of 0.05 degrees Celsius (Applied Microsystems Ltd., 2005).

Process_Date: 20080429

Process_Step:

Process_Description:

Sonar Sounding Processing - GPS data and measurements of vessel motion were combined in the F180 hardware to produce a high-precision vessel attitude packet. This packet was transmitted to the Swath Processor acquisition software in real time and combined with instantaneous sound velocity measurements at the transducer head before each ping. As many as 20 pings per second were transmitted with each ping consisting of 2,048 samples per side (port and starboard). The returned samples were projected to the seafloor using a ray-tracing algorithm working with the previously measured sound-velocity profiles in SEA Swath Processor (version 3.07.12.0). A series of statistical filters were applied to the raw samples that isolated the seafloor returns from other spurious targets in the water column. Finally, the processed data is stored line-by-line in both raw (.sxr) and processed (.sxp) trackline files. Processed (.sxp) files were further processed with SXPEGN (build 151) by David Finlayson (USGS) to remove erroneous data from the files and produce valid gain-normalized amplitude data for processing backscatter data.

Process_Date: 20111207

Process_Step:

Process_Description:

Backscatter Image Production - The raw 16-bit backscatter recorded simultaneously with the bathymetry by the SWATHplus was georeferenced and gain-normalized by the program SXPEGN, software written by the USGS to enhance the backscatter of the SWATHplus system. The program normalizes for time-varying signal loss and beam directivity differences. The resulting normalized amplitude values are re-scaled to 16-bit, exported as point files and gridded into GeoJPEGS using GRID Processor, software supplied by SEA. Normalized acoustic backscatter shows the relative strength of the acoustic signal returned from the seafloor. The normalization process compensates for acoustic signal strength differences due to time varying gain (TVG), spreading and many static sonar artifacts (those that repeat from ping-to-ping). The values are comparable across the entire dataset regardless of water depth or distance and angle from the transducer. Low normalized acoustic backscatter values indicate relatively low acoustic target signal strength; High normalized acoustic backscatter values indicate relatively high acoustic target signal strength.

Process_Date: 20111207

Process_Step:

Process_Description:

Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed.

Process_Date: 20201019
Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross

Contact_Position: Marine Geologist
Contact_Address:

Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598

Contact_Voice_Telephone: 508-548-8700 x2251
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov

Process_Step:

Process_Description:

Corrected working URL links to cmgds data repository to the actual published links

Process_Date: 20210317
Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: U.S. Geological Survey
Contact_Person: Susan A. Cochran

Contact_Position: Geologist
Contact_Address:

Address_Type: Mailing and Physical
Address: 2885 Mission Street
City: Santa Cruz
State_or_Province: CA
Postal_Code: 95060

Contact_Voice_Telephone: 831-460-7545
Contact_Electronic_Mail_Address: scochran@usgs.gov

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:

Raster_Object_Type: Grid Cell
Row_Count: 6833
Column_Count: 5172

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Grid_Coordinate_System:

Grid_Coordinate_System_Name: Universal Transverse Mercator
Universal_Transverse_Mercator:

UTM_Zone_Number: 11
Transverse_Mercator:

Scale_Factor_at_Central_Meridian: 0.9996
Longitude_of_Central_Meridian: -117
Latitude_of_Projection_Origin: 0.0
False_Easting: 500000
False_Northing: 0.0

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: row and column
Coordinate_Representation:

Abscissa_Resolution: 1.0
Ordinate_Resolution: 1.0

Planar_Distance_Units: meters

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983 (CORS96)
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137
Denominator_of_Flattening_Ratio: 298.257

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: Normalized Acoustic Backscatter Amplitude
Entity_Type_Definition:

The raw 16-bit backscatter recorded simultaneously with the bathymetry by the SWATHplus was georeferenced and gain-normalized by the program SXPEGN, software written by the USGS to enhance the backscatter of the SWATHplus system. The program normalizes for time-varying signal loss and beam directivity differences. The resulting normalized amplitude values are re-scaled to 16-bit, exported as point files and gridded into GeoJPEGS using GRID Processor, software supplied by SEA. Normalized acoustic backscatter shows the relative strength of the acoustic signal returned from the seafloor. Normalization process compensates for acoustic signal strength differences due to time varying gain (TVG), spreading and many static sonar artifacts (those that repeat from ping-to-ping). The values are comparable across the entire dataset regardless of water depth or distance and angle from the transducer. Low normalized acoustic backscatter values indicate relatively low acoustic target signal strength; High normalized acoustic backscatter values indicate relatively high acoustic target signal strength.

Entity_Type_Definition_Source: Producer defined

Overview_Description:

Entity_and_Attribute_Overview:

The complete 2008 1-m resolution grid "S-5-08-SC_backscatter_nad83_utm11_1m.tif" was originally archived as a TIFF image with the following attributes.

Cell size = 1.0
Number of rows = 6833
Number of columns = 5172

Data type = floating point

Boundary
Xmin = 483039
Xmax = 488211
Ymin = 3599596
Ymax = 3606429

Statistics
Minimum value = 0
Maximum value = 65535
Mean = 32848
Standard deviation = 17300

Coordinate system description
Projection  UTM
Zone  11
Datum  NAD83
Units  meter

Entity_and_Attribute_Detail_Citation: U.S. Geological Survey

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

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

Contact_Address:

Address_Type: Mailing and Physical
Address: 2885 Mission Street
City: Santa Cruz
State_or_Province: CA
Postal_Code: 95060

Contact_Voice_Telephone: 1-888-427-4747
Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov

Resource_Description:

These data are available in GeoTIFF format, including a tif world file (.tfw) and CSDGM FGDC-compliant metadata.

Distribution_Liability:

Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: GeoTIFF
Format_Version_Number: ArcMap (version 10.3.1)
Format_Information_Content:

Downloadable zip file contains the TIFF (.tif) version of the backscatter data and a projection file (.tfw).

File_Decompression_Technique: WinZip
Transfer_Size: 47.2

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name:

https://cmgds.marine.usgs.gov/data-releases/media/2020/10.5066-P9Y8CDFI/38d99e2a24514f778b40d04aa415207b/S-5-08-SC_backscatter_nad83_utm11_1m.zip

Network_Resource_Name:

https://cmgds.marine.usgs.gov/data-releases/datarelease/10.5066-P9Y8CDFI/dataset/16/

Network_Resource_Name: https://doi.org/10.5066/P9Y8CDFI

Access_Instructions:

Data can be downloaded using the Network_Resource_Name links. The first link is a direct link to download the zipped file of backscatter data image. The second link points to a landing page with the backscatter data image, metadata, and a browse image. The third link points to the landing page for the entire data release, including links to pages of the various data files.

Fees: None.

Technical_Prerequisites:

The downloadable data file has been compressed with the "zip" command and can be unzipped with Winzip (or other tool) on Windows systems. To utilize these data, the user must have software capable of uncompressing the WinZip file and importing and viewing a GeoTIFF file.

Metadata_Reference_Information:

Metadata_Date: 20210317
Metadata_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

Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998

This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/DataReleases/CMGDS_DR_tool/DR_P9Y8CDFI/S-5-08-SC_backscatter_nad83_utm11_1m_metadata.html>