Identification_Information: Citation: Citation_Information: Originator: Andrew W. Stevens Originator: Guy Gelfenbaum Publication_Date: 2012 Title: Southwest Washington Littoral Drift Restoration: Beach and Nearshore Morphological Monitoring Geospatial_Data_Presentation_Form: raster digital data Larger_Work_Citation: Citation_Information: Originator: Andrew W. Stevens Originator: Guy Gelfenbaum Publication_Date: 2012 Title: Southwest Washington Littoral Drift Restoration: Beach and Nearshore Morphological Monitoring Series_Information: Series_Name: U.S. Geological Survey Open-File Report Issue_Identification: 2012-1175 Publication_Information: Publication_Place: Santa Cruz, California Publisher: U.S. Geological Survey Online_Linkage: http://pubs.usgs.gov/of/2012/1175/ Description: Abstract: Purpose: Results from repeated surveys of beach topography and nearshore bathymetry are presented to document the placement and dispersal of a beach nourishment placed within a high-energy nearshore environment located within the Columbia River Littoral Cell (CRLC). Supplemental_Information: Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20100711 Ending_Date: 20111123 Currentness_Reference: ground condition Status: Progress: complete Maintenance_and_Update_Frequency: as needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -124.0753 East_Bounding_Coordinate: -124.0795 North_Bounding_Coordinate: 46.3078 South_Bounding_Coordinate: 46.2635 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: elevation Theme_Keyword: geoscientificinformation Theme_Keyword: oceans Theme: Theme_Keyword_Thesaurus: NASA Global Change Master Directory (GCMD) Science Keywords Theme_Keyword: OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > BATHYMETRY Theme_Keyword: OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > SEAFLOOR TOPOGRAPHY Theme_Keyword: OCEANS > COASTAL PROCESSES > ESTUARIES Theme: Theme_Keyword_Thesaurus: NASA Global Change Master Directory (GCMD) Platform Keywords Theme_Keyword: DEM > Digital Elevation Model Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: State of Washington Place_Keyword: Pacific Ocean Place_Keyword: Benson Beach Access_Constraints: If physical samples or materials are available, constraints on their on-site access are described in "WR CMG Sample Distribution Policy" at URL: http://walrus.wr.usgs.gov/infobank/programs/html/main/sample-dist-policy.html Use_Constraints: This information is not intended for navigational purposes. Read and fully comprehend the metadata prior to data use. Uses of these data should not violate the spatial resolution of the data. Where these data are used in combination with other data of different resolution, the resolution of the combined output will be limited by the lowest resolution of all the data. Acknowledge the U.S. Geological Survey in products derived from these data. Share data products developed using these data with the U.S. Geological Survey. This database has been approved for release and publication by the Director of the USGS. Although this database has been subjected to technical review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use. Although this Federal Geographic Data Committee-compliant metadata file is intended to document these data in nonproprietary form, as well as in ArcInfo format, this metadata file may include some ArcInfo-specific terminology. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: USGS Pacific Coastal and Marine Science Center Contact_Person: Andrew W. Stevens Contact_Position: Oceanographer Contact_Address: Address_Type: physical address Address: U.S. Geological Survey Address: 400 Natural Bridges Drive City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Country: USA Contact_Voice_Telephone: (831) 460-7424 Contact_Facsimile_Telephone: (831) 427-4709 Contact_Electronic_Mail_Address: astevens@usgs.gov Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: This bathymetric data has not been independently verified for accuracy. Logical_Consistency_Report: All bathymetric values are derived from the same instruments and processing workflow. Completeness_Report: Elevation data were collected along Benson Beach, a 3-km stretch of coastline located between the Mouth of the Columbia River (MCR) North Jetty to the south and North Head to the north, at the southern end of the Long Beach peninsula in Washington State. Bathymetric and topographic measurements were collected primarily along a series of cross-shore transects that extended from roughly the -10 m contour (NAVD88) to just landward of the primary dune crest. Horizontal_Positional_Accuracy_Report: The uncertainty associated with the survey-grade GPS used in this study is approximately ±3 cm + 2 ppm in the horizontal while operating in RTK surveying mode, where ppm is relative to the distance (baseline) to the GPS base station (Trimble Navigation Limited, 1998). Baselines during this survey were less than 3 km, resulting in estimated horizontal uncertainties of ±4 cm. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: The uncertainty associated with the survey-grade GPS used in this study is approximately ±5 cm + 2 ppm in the vertical while operating in RTK surveying mode, where ppm is relative to the distance (baseline) to the GPS base station (Trimble Navigation Limited, 1998). Baselines during this survey were less than 3 km, resulting in estimated vertical uncertainties of ±6 cm. Variability in seawater temperature and salinity (not measured) affect the speed of sound in water, and thus the calculated depth for bathymetric sonar measurements. Fluctuations in seawater properties were can affect depth soundings by approximately 1% of water depth, resulting in total vertical uncertainty between 8 cm for shallow areas and 26 cm for the deepest portions of the study area. Lineage: Process_Step: Process_Description: Sonar Data Collection Nearshore bathymetry was measured using single-beam sonar systems GPS receivers mounted on personal watercraft (PWC). The sonar systems consisted of an Odom Echotrac CV-100 single-beam echosounder and 200 kHz transducer (20° beam angle). Raw acoustic backscatter returns were digitized by the echosounder with a vertical resolution of 1.25 cm. Depths from the echosounder were computed assuming a sound velocity of 1500 m/s. The horizontal and vertical position of the survey vessels was determined at 20-Hz using Trimble R7 GPS receivers with Zephyr 2 GPS antennas operating in real-time kinematic (RTK) mode. Output from the RTK-GPS and sonar systems were combined in real time on the PWC by a computer running Hypack hydrographic survey software. Electronic components of the survey systems were housed in water-tight cases and attached to the stern of the survey vessels. Navigation information was displayed on a video monitor, allowing PWC operators to navigate along survey lines at speeds of 2-3 m/s. Process_Date: 20120411 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 at 1 s intervals. The base station was located within Cape Dissappointment State Park. The base station was programmed using the NAD83 (1991). The vertical postion of the benchmark was determed by differential leveling and adjusted by the National Geodetic Survey in 1991. Average Opus Solution coordinates for the station are: >Reference Frame: NAD83 (1991) >Latitude: N 46 16 35.91561 >Longitude: W 124 03 59.09172 >Ellipsoid Height: -19.651 m >Orthometric Height: 4.678 m >Washington State Plane South, Northing: 111061.382 m >Washington State Plane South, Easting: 225226.997 m Process_Date: 20120411 Process_Step: Process_Description: Sonar Sounding Processing Bathymetric data were downloaded from the survey computers and post-processed using a custom Graphical User Interface (GUI) programmed with the computer program Matlab. Digitized depths were compared to the raw acoustic backscatter signal to ensure accuracy of depths produced by the echosounder, and the GUI was used to digitize the bottom by hand where the echosounder signal processing failed. This was common in the surf zone, where turbulence and bubbles in the water column added noise to the acoustic signal. After the raw depths were adjusted, a running mean with a window length of 5-20 points (1-6 m distance) was used to remove high-frequency vertical fluctuations such as those caused by pitch and roll of the survey vessels. Process_Date: 20120411 Process_Step: Process_Description: Digital Elevation Model Production Digital elevation models (DEMs) were constructed from processed bathymetric and topographic point data using linear interpolation with a grid resolution of 5 m. All available data were used to generate the gridded surfaces. The gridded surfaces were manually edited to ensure that the linear interpolation did not interpolate across areas not covered by field measurements. Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: raster Raster_Object_Information: Raster_Object_Type: grid cell Row_Count: 981 Column_Count: 461 Spatial_Reference_Information: 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 Lamber 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: 0.0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: row and column Coordinate_Representation: Abscissa_Resolution: 5.0 Ordinate_Resolution: 5.0 Planar_Distance_Units: meters Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 (1991) 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 1988 Altitude_Resolution: 0.01 Altitude_Distance_Units: meters Altitude_Encoding_Method: Attribute values Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: Altitude Entity_Type_Definition: Orthometric Altitude (elevation) relative to NAVD88 in meters. Values are positive up. Entity_Type_Definition_Source: USGS Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center (PCMSC) Contact_Person: Andrew W. Stevens Contact_Address: Address_Type: mailing and physical address Address: U.S. Geological Survey Address: 400 Natural Bridges Drive City: Santa Cruz State_or_Province: CA Postal_Code: 95060-5792 Country: US Contact_Voice_Telephone: 831-460-7424 Contact_Facsimile_Telephone: 831-427-4709 Contact_Electronic_Mail_Address: astevens@usgs.gov Resource_Description: Downloadable Data Distribution_Liability: This information is not intended for navigational purposes. This database has been approved for release and publication by the Director of the USGS. Although this database has been subjected to technical review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ESRI ASCII Grid Format_Version_Number: 1.0 Format_Information_Content: The ASCII file consists of header information containing a set of keywords, followed by cell values in row-major order. The file format is: > > > > > > > {NODATA_VALUE xxx} > row 1 > row 2 > . > . > . > row n > where xxx is a number, and the keyword nodata_value is optional and defaults to -9999.99. Row 1 of the data is at the top of the grid, row 2 is just under row 1 and so on. The nodata_value is the value in the ASCII file to be assigned to those cells whose true value is unknown. In the grid they will be assigned the keyword NODATA. Cell values are be delimited by spaces. No carriage returns are necessary at the end of each row in the grid (although they are included in this case). The number of columns in the header is used to determine when a new row begins. The number of cell values is equal to the number of rows times the number of columns. Transfer_Size: 4 MB Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://pubs.usgs.gov/of/2012/1175/ Fees: No cost Metadata_Reference_Information: Metadata_Date: 20120411 Metadata_Review_Date: 20120207 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Pacific Coastal and Marine Science Center (PCMSC), US Geological Survey Contact_Address: Address_Type: mailing address Address: U.S. Geological Survey Address: 400 Natural Bridges Drive City: Santa Cruz State_or_Province: California Postal_Code: 95060 Country: USA Contact_Voice_Telephone: 8314607424 Contact_Electronic_Mail_Address: astevens@usgs.gov Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998