Nearshore Bathymetry in the CRLC, Grayland subcell - summer 1998

Citation:

Citation Information:

Originator: U.S. Geological Survey, Coastal and Marine Geology Program
Publication Date: Unpublished Material
Publication Time: Unknown
Title: Nearshore Bathymetry in the CRLC, Grayland subcell - summer 1998
Online Linkage: http://www.ecy.wa.gov/programs/sea/swces/index.htm

Description:

Abstract:
The sub-aerial, or visible beach comprises only a portion of the active coastal zone. Variability in sub-aqueous morphology can influence the amount of energy from waves that is available to impact the shoreline and cause beach change. It has historically been very difficult and expensive to collect data in this highly dynamic region and only a few coastlines in the world have sufficient nearshore data to quantify this variability. The Coastal Profiling System (CPS) is a hydrographic surveying system mounted on a Personal Watercraft (PWC) originally designed by Oregon State University (Beach et al., 1996; Côté, 1999; MacMahan, 2001) to collect data in energetic nearshore environments. A pilot effort was initiated in 1998 to test whether or not the CPS could be used in the Columbia River littoral cell in the Pacific Northwest USA to collect regional nearshore bathymetric data.
Purpose:
Nearshore bathymetry data is being collected as a component of the beach morphology monitoring program of the Southwest Washington Coastal Erosion Study. The primary goals of the monitoring program are to 1) quantify the short-medium term (event-seasonal-interannual) beach change rates and morphologic variability along the Columbia River littoral cell, 2) collect beach state parameter (grain size, beach slope, dune/sandbar height/position) data to enhance the conceptual understanding of the CRLC functioning and refine predictions of future coastal change, 3) compare and contrast the scales of environmental forcing and beach change with other coastlines of the world, and 4) provide relevant beach change data in an appropriate format to coastal decision-makers.
Supplemental Information:
A description of the methodology used to collect this data is available in the USGS Open File Report: Beach Monitoring in the Columbia River Littoral Cell: 1997 - 2002.

The following is a list of publications cited in this report:

Beach, R.A.; Holman, R.A.; and Stanley, J., 1996. Measuring nearshore bathymetry on high energy beaches.
American Geophysical Union Fall Meeting, 1996, F286.

Birkemeier, W. A., and Mason, C., 1984. The CRAB: A Unique nearshore Surveying Vehicle. Journal of
Surveying Engineering, 110(1), 1-7.

Cote, J.M., 1999. The measurement of nearshore bathymetry on Intermediate and dissipative beaches.
Unpublished Masters Thesis, Oregon State University, Corvallis, Oregon, 102 pp.

Daniels, R.C., P. Ruggiero, and L.E. Weber, 1999. Washington coastal geodetic control network: report and
station index, Washington Department of Ecology, Coastal Monitoring & Analysis Program, Publication
#99-103, 268 p.

MacMahan, J., 2001. Hydrographic surveying from a personal watercraft. Journal of Surveying Engineering,
127(1), 12-24.

Gelfenbaum, G., Sherwood, C.R., Kerr, L.A., and Kurrus, K., 2000. Grays Harbor wave refraction experiment
1999: Data report, US Geological Survey Open File Report, OF 00-44, 132 pp.

Trimble Navigation Limited, 1998. 4700 Receiver Operation Manual. Version 1.0, Part Number 36238-00,
Revision B.

UNESCO, 1982. Algorithms for computation of fundamental properties of seawater. 44, Unesco/SCOR/ICES/IAPSO Joint Panel.

Time Period of Content:

Time Period Information:

Range of Dates/Times:

Beginning Date: 7/15/1998
Beginning Time: Unknown
Ending Date: 7/16/1998
Ending Time: Unknown

Currentness Reference: ground condition

Status:

Progress: Complete
Maintenance and Update Frequency: None planned

Spatial Domain:

Bounding Coordinates:

West Bounding Coordinate: -124.2787
East Bounding Coordinate: -123.6226
North Bounding Coordinate: 47.3214
South Bounding Coordinate: 45.8547

Keywords:

Theme:

Theme Keyword Thesaurus: nearshore bathymetry
Theme Keyword: cross-shore transect
Theme Keyword: Global Positioning System
Theme Keyword: seasonal variability
Theme Keyword: beach profile
Theme Keyword: sandbars
Theme Keyword: sediment transport
Theme Keyword: beach monitoring
Theme Keyword: beaches
Theme Keyword: beach morphology
Theme Keyword: beach survey
Theme Keyword: hydrographic surveying
Theme Keyword: topographic surveying

Place:

Place Keyword Thesaurus: CMAP Region
Place Keyword: Astoria
Place Keyword: Clatsop Plains
Place Keyword: Clatsop Spit
Place Keyword: Columbia River Littoral Cell
Place Keyword: Copalis Beach
Place Keyword: Fort Canby
Place Keyword: Gearheart
Place Keyword: Grayland Plains
Place Keyword: Klipsan
Place Keyword: Leadbetter Point
Place Keyword: Long Beach
Place Keyword: Moclips
Place Keyword: North Beach
Place Keyword: North Cove
Place Keyword: Ocean City
Place Keyword: Ocean Park
Place Keyword: Ocean Shores
Place Keyword: Oregon
Place Keyword: Pacific Beach
Place Keyword: Point Grenville
Place Keyword: Seaside
Place Keyword: Seaview
Place Keyword: Tillamook Head
Place Keyword: Washington
Place Keyword: Westport

Access Constraints: None
Use Constraints:
Users must assume liability to determine the appropiate use of these data. This data set is not to be used for legal purposes. The Coastal and Marine Geology Program, US Geological Survey should be acknowledged as the data source in products derived from these data. Please contact the USGS for more detailed information if required.
Point of Contact:

Contact Information:

Contact Person Primary:

Contact Person: Peter Ruggiero
Contact Organization: United States Geological Survey

Contact Position: Coastal Engineer
Contact Address:

Address Type: mailing and physical address
Address:
Coastal and Marine Geology Program, MS-999, 345 Middlefield Road

City: Menlo Park
State or Province: CA
Postal Code: 94025
Country: USA

Contact Voice Telephone: 650-329-5433
Contact Facsimile Telephone: 650-329-5190
Contact Electronic Mail Address: pruggiero@usgs.gov
Hours of Service: Monday-Friday, 8:00 AM to 5:00 PM PST/PDT

Data Set Credit:
These data were collected as part of the Southwest Washington Coastal Erosion Study which is jointly funded by the Washington State Department of Ecology (Coastal Monitoring & Analysis Program) and the US Geological Survey (Coastal and Marine Geology Program).
Native Data Set Environment: ASCII text file, Windows NT 4.0 OS.

Logical Consistency Report: The fidelity of the data is ensured via the use of survey grade GPS recievers and geodetic control monuments within the Washington Coastal Geodetic Control Network (Daniels et al., 1999).
Completeness Report: The data is visually inspected for gross inacuracies using a variety of software packages including MS Excel and Matlab (Mathworks Inc.).
Positional Accuracy:

Horizontal Positional Accuracy:

Horizontal Positional Accuracy Report:
The survey-grade GPS equipment used in the monitoring program (Trimble 4000 series receivers) have manufacturer reported Root Mean Square (RMS) accuracies of approximately ±3-cm + 2ppm of baseline length (typically 10 km or less) in the horizontal while operating in Real Time Kinematic surveying mode (Trimble Navigation Limited, 1998). These reported accuracies are, however, additionally subject to multi-path, satellite obstructions, poor satellite geometry, and atmospheric conditions. A calibration was performed to constrain the horizontal and vertical coordinates to the Washington Coastal Geodetic Control Network (Daniels et al., 1999). The horizontal resolution of the calibration was typically better than 0.05 meters. While the horizontal uncertainty of individual data points is approximately 0.05 m, the CPSI operators could at times be up to approximately 100 m off of a true shore perpendicular transect due to the methodology of sighting range poles on the beach.
Quantitative Horizontal Positional Accuracy Assessment:

Horizontal Positional Accuracy Value: 0.05
Horizontal Positional Accuracy Explanation:
The survey-grade GPS equipment used in the monitoring program (Trimble 4000 series receivers) have manufacturer reported RMS accuracies of approximately ±3-cm + 2ppm of baseline length (typically 10 km or less) in the horizontal while operating in Real Time Kinematic surveying mode (Trimble Navigation Limited, 1998).
Vertical Positional Accuracy:

Vertical Positional Accuracy Report:
The survey-grade GPS equipment used in the monitoring program (Trimble 4000 series receivers) have manufacturer reported RMS accuracies of approximately ±5-cm + 2ppm of baseline length (typically 10 km or less) in the vertical while operating in Real Time Kinematic surveying mode (Trimble Navigation Limited, 1998). These reported accuracies are, however, additionally subject to multi-path, satellite obstructions, poor satellite geometry, and atmospheric conditions that can combine to cause a vertical GPS drift that can be as much as 10-cm.

Following the initial field trials the primary test of the CPSI took place in October 1997 at the SandyDuck 97 field experiment at the USACE Field Research Facility (FRF) in Duck, North Carolina where the bathymetric data collected by the CPS were compared against the data collected by the CRAB (Birkemeir et al., 1984). Error analyses from these tests indicate that the system typically maintains sub-decimeter vertical accuracy (Cote, 1999).

While repeatability tests and merges with topographic data suggest sub-decimeter vertical accuracy (MacMahan, 2001), variability in seawater temperature (not usually measured) can affect depth estimates by as much as 20 cm in 12 m of water. However, water temperatures typically fluctuate only a few degrees within the CRLC.

A calibration was performed to constrain the horizontal and vertical coordinates to the Washington Coastal Geodetic Control Network (Daniels et al., 1999). The vertical resolution of the calibration was typically better than 0.10 meters.

The final vertical data was extracted from uniform 2-dimensional grids and therefore a conservative estimate of the total vertical uncertainty is 0.20 meters.

Quantitative Vertical Positional Accuracy Assessment:

Vertical Positional Accuracy Value: 0.2
Vertical Positional Accuracy Explanation:
The survey-grade GPS equipment used in the monitoring program (Trimble 4000 series receivers) have manufacturer reported RMS accuracies of approximately ±5-cm + 2ppm of baseline length (typically 10 km or less) in the vertical while operating in Real Time Kinematic surveying mode (Trimble Navigation Limited, 1998).
Lineage:

Process Step:

Process Description:
A Real Time Kinematic Differential Global Positioning System (RTK DGPS) base station was setup on a control monument within the Washington Coastal Geodetic Control Network (Daniels et al., 1999). An RTK DGPS base station consists of a Trimble 4400 receiver, a Trimble non-micro centered T1/T2 GPS antenna with a ground plane, a Pacific Crest UHF radio modem, radio antenna, two tripods, and various cables. The GPS antenna was mounted onto a tripod that was leveled over the monument. Once leveled the tripod was secured with sand bags and the antenna was connected to the GPS receiver via a data cable. The radio modem and antenna are attached to the second tripod and connected to the GPS receiver via a data cable. After all connections were made, the Trimble 4400 receiver was started using a TDC1 handheld data logger and the radio modem was turned on.
Process Step:

Process Description:
The CPSI was configured on a Yamaha Waverunner III 2 cycle, 62 horsepower PWC that is 3 m long and 1.1 m wide. A Meridata MD 100 fan beam echo sounder was used with the transducer (12.5 ° beam width) mounted in the hull at the stern of the PWC. The MD 100 operates at 200 kHz, samples at 1 Hz, and is capable of measuring in water depths ranging from 1 - 180 m, with a resolution of approximately 0.1 m. The CPSI incorporates a Trimble (4000 series) RTK-DGPS reciever operating at 5 Hz and a T1/T2 non-microcented GPS antenna mounted approximately in the center line of the boat, directly over the echo sounder transducer, on an A-frame at the stern of the PWC. A daylight-readable Liquid Crystal Display (LCD) provides the PWC operator with GPS status, speed of vessel, and depth information. Data from the CPSI were collected in an onboard computer system and stored on a 32 MB PCMCIA card.
Process Step:

Process Description:
Prior to launching the CPSI, discrepancies between local control and GPS-derived coordinates were reduced by conducting a field calibration (also referred to as horizontal and vertical adjustments). This calibration was accomplished by obtaining between two and three calibration points at markers of known elevation and horizontal position in the vicinity of the survey area. Calibration points are measured by initializing the CPSI system, centering the GPS antenna over a known marker at a set height and recording data for several minutes. If precisions are satisfactory, the calibration points are used to perform a least squared fit spatial correction on all survey points collected to constrain the horizontal and vertical coordinates to the Washington Coastal Geodetic Control Network (Daniels et al., 1999).
Process Step:

Process Description:
The CPSI was completely initialized on land and then recorded data continuously until the PWC was retrieved from the water and powered down. While data was collected continuously, the CPSI operator only concentrated on maintaining data quality while moving along cross-shore transects, beginning in deep water, approximately 10-12 m NAVD88, and ending within the surf zone. Three range poles were used on the beach to align the individual shore perpendicular transects. This cross-shore (onshore) only operation of the CPSI minimized the affect of roll and pitch on depth estimates. The alongshore spacing between cross-shore profiles was typically around 200 m. However, due to the methodology of sighting range poles on the beach the CPSI operators could at times be up to approximately 100 m off of a true shore perpendicular transect . The CPS surveys were conducted near high tide to maximize the landward limit of the profile measurements.
Process Step:

Process Description:
As often as possible the nearshore bathymetry data were combined with topographic surveys, extending the cross-shore profiles onto the sub-aerial beach and landward to the dune fields. Topographic cross-shore beach profiles were extracted from topographic beach surface maps collected with an RTK DGPS reciever and antenna mounted to a six-wheel drive amphibious all-terrain vehicle called the CLAMMER (CoastaL All-terrain Morphology Monitoring and Erosion Research vehicle). In most cases, topographic beach surface maps were collected at low tide within approximately 24 hours of the bathymetry measurements. The topographic beach profiles were extracted from a uniform 2-dimensional gridded topographic surface such that alongshore grid positions agreed with the alongshore positions of the bathymetry profiles. The CLAMMER collects dense three-dimensional topographic surface data. Each of these surface maps is approximately 4-km in alongshore length and extend from the base of the dune to the low tide water line in the cross-shore.
Process Step:

Process Description:
The GPS and echo sounder were sampled at different rates and recorded separately. However the need to estimate the tidal elevation of the water surface is eliminated by the co-collection of depth data and an accurate GPS vertical position. The GPS data, sampled at 5 Hz, was recorded in the WGS84 datum. The program Corpscon (US Army Corps of Engineers) was used to convert to the Washington State Plane, South Region (4602), NAD83 horizontal datum and the NAVD88 land-based vertical datum. A cubic spline interpolation using a piece-wise polynomial fit obtains the GPS coordinates for the echo sounder depth at a specified location and time. The elevation of both data streams are then subtracted to obtain the depth of the seafloor in NAVD88
Process Step:

Process Description:
Although the CPSI collected data continuously, bathymetric profiles were only derived from measurements taken while driving onshore in order to minimize the influence of waves on the measurements. Individual data points below the echo sounders blanking interval (0.0 - 0.6 m) and points 1.75 m above a linear regression through the data were removed as outliers. A second pass through the data removed points 0.5 m vertically different from nearest neighbor data points. These two steps typically reduce data density by approximately 15%.
Process Step:

Process Description:
A smoothing operation was performed using a ten point median filter on the vertical coordinate in the onshore direction to reduce high frequency fluctuations from the nearshore bathymetry data. Varying window sizes were used to obtain a smooth profile while maintaining the integrity of the actual data points.
Process Step:

Process Description:
The final data processing step used on the 1998 data set is an elevation correction resulting from differences between the actual speed of sound in water (see Enviro_cond_98.xls) and the preset speed of sound that was typically set equal to 1450 m/sec. The speed of sound calibration uses the UNESCO (1982) algorithm (2) for the computation of the speed of sound in seawater. Data from each day of collection in 1998 that have been processed in the above manner and stored as ASCII Easting, Northing, Elevation triplets are considered the ‘raw’ data files.
Process Step:

Process Description:
Profiles in the subsequent years of this surveying campaign were collected along preset track lines. In order to compare the 1998 data to these subsequent profiles a further processing step is necessary. Both the bathymetry data and the topography data were mapped onto a uniform 2-dimensional gridded surface from which beach profiles falling along the subsequent track lines are extracted. These individual profiles stored as ASCII Easting, Northing, Elevation triplets are considered the 'final' output for the 1998 data set.
Process Contact:

Contact Information:

Contact Person Primary:

Contact Person: Peter Ruggiero
Contact Organization: United States Geological Survey

Contact Position: Coastal Engineer
Contact Address:

Address Type: mailing and physical address
Address:
Coastal and Marine Geology Program, MS-999, 345 Middlefield Road

City: Menlo Park
State or Province: CA
Postal Code: 94025
Country: USA

Contact Voice Telephone: 650-329-5433
Contact Facsimile Telephone: 650-329-5190
Contact Electronic Mail Address: pruggiero@usgs.gov
Hours of Service: Monday-Friday, 8:00 AM to 5:00 PM PST/PDT

Cloud Cover: Unknown

Direct Spatial Reference Method: Point
Point and Vector Object Information:

SDTS Terms Description:

SDTS Point and Vector Object Type: Point

Horizontal Coordinate System Definition:

Planar:

Grid Coordinate System:

Grid Coordinate System Name: State Plane Coordinate System 1983
State Plane Coordinate System:

SPCS Zone Identifier: Washington, South
Lambert Conformal Conic:

Standard Parallel: 45.833333
Standard Parallel: 47.333333
Longitude of Central Meridian: -120.5
Latitude of Projection Origin: 45.333333
False Easting: 500000
False Northing: 0

Planar Coordinate Information:

Planar Coordinate Encoding Method: Coordinate Pair
Planar Distance Units: meters

Geodetic Model:

Horizontal Datum Name: North American Datum of 1983
Ellipsoid Name: Geodetic Reference System 80
Semi-major Axis: 6378137
Denominator of Flattening Ratio: 298.257

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

Detailed Description:

Entity Type:

Entity Type Label: lb98_line033_b.xyz
Entity Type Definition: ASCII text file

Attribute:

Attribute Label: Easting
Attribute Definition: Easting coordinate position.
Attribute Definition Source: US Geological Survey, Coastal and Marine Geology Program
Attribute Value Accuracy Information:

Attribute Value Accuracy: 0.05

Attribute Measurement Frequency: Irregular

Attribute:

Attribute Label: Elevation
Attribute Definition: Elevation measurement of the data point.
Attribute Definition Source: US Geological Survey, Coastal and Marine Geology Program
Attribute Value Accuracy Information:

Attribute Value Accuracy: 0.2

Attribute Measurement Frequency: Irregular

Attribute:

Attribute Label: Northing
Attribute Definition: Value of the Northing coordinate
Attribute Definition Source: US Geological Survey, Coastal and Marine Geology Program
Attribute Value Accuracy Information:

Attribute Value Accuracy: 0.05

Attribute Measurement Frequency: Irregular

Detailed Description:

Entity Type:

Entity Type Label: lb98_line034_b.xyz
Entity Type Definition: ASCII text file

Detailed Description:

Entity Type:

Entity Type Label: lb98_line035_b.xyz
Entity Type Definition: ASCII text file

Detailed Description:

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Entity Type Label: lb98_line036_b.xyz
Entity Type Definition: ASCII text file

Detailed Description:

Entity Type:

Entity Type Label: lb98_line037_b.xyz
Entity Type Definition: ASCII text file

Detailed Description:

Entity Type:

Entity Type Label: lb98_line038_b.xyz
Entity Type Definition: ASCII text file

Detailed Description:

Entity Type:

Entity Type Label: lb98_line039_b.xyz
Entity Type Definition: ASCII text file

Detailed Description:

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Entity Type Label: lb98_line040_b.xyz
Entity Type Definition: ASCII text file

Detailed Description:

Entity Type:

Entity Type Label: lb98_line041_b.xyz
Entity Type Definition: ASCII text file

Detailed Description:

Entity Type:

Entity Type Label: lb98_line042_b.xyz
Entity Type Definition: ASCII text file

Overview Description:

Entity and Attribute Overview: ASCII text file that includes: Easting, Northing, Elevation.

Distributor:

Contact Information:

Contact Person Primary:

Contact Person: Peter Ruggiero
Contact Organization: United States Geological Survey

Contact Position: Coastal Engineer
Contact Address:

Address Type: mailing and physical address
Address:
Coastal and Marine Geology Program, MS-999, 345 Middlefield Road

City: Menlo Park
State or Province: CA
Postal Code: 94025
Country: USA

Contact Voice Telephone: 650-329-5433
Contact Facsimile Telephone: 650-329-5190
Contact Electronic Mail Address: pruggiero@usgs.gov
Hours of Service: Monday-Friday, 8:00 AM to 5:00 PM PST/PDT

Distribution Liability:
Users must assume liability to determine the appropiate use of these data. This data set is not to be used for legal purposes. The Coastal and Marine Geology Program, US Geological Survey should be acknowledged as the data source in products derived from these data. Please contact the US Geological Survey for more detailed information if required.
Standard Order Process:

Standard Order Process:

Fees: May involve cost recovery for production of CD-ROM. Please contact Peter Ruggiero for additional information and report availability.
Ordering Instructions: Contact Peter Ruggiero at the US Geological Survey.

Custom Order Process:
Please contact Peter Ruggiero at the US Geological Survey for ordering information, or view the Southwest Washington Coastal Erosion Study Internet site at http://www.ecy.wa.gov/programs/sea/swces/index.htm for data download information.
Available Time Period:

Time Period Information:

Single Date/Time:

Calendar Date: 5/9/2003
Time of Day: Unknown

Metadata Date: 5/9/2003
Metadata Review Date: 5/9/2003
Metadata Future Review Date:
Metadata Contact:

Contact Information:

Contact Person Primary:

Contact Person: Peter Ruggiero
Contact Organization: United States Geological Survey

Contact Position: Coastal Engineer
Contact Address:

Address Type: mailing and physical address
Address:
Coastal and Marine Geology Program, MS-999, 345 Middlefield Road

City: Menlo Park
State or Province: CA
Postal Code: 94025
Country: USA

Contact Voice Telephone: 650-329-5433
Contact Facsimile Telephone: 650-329-5190
Contact Electronic Mail Address: pruggiero@usgs.gov
Hours of Service: Monday-Friday, 8:00 AM to 5:00 PM PST/PDT

Metadata Standard Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata Time Convention: local time
Metadata Security Information:

Metadata Security Classification: Unclassified