Metadata: Identification_Information: Citation: Citation_Information: Originator: Theresa A. Fregoso Originator: Bruce E. Jaffe Originator: Amy C. Foxgrover Publication_Date: 20210708 Title: Digital elevation model (DEM) of south San Francisco Bay, California, created using bathymetry data collected between 2005 and 2020 (MLLW) Geospatial_Data_Presentation_Form: Raster Digital Data Set Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P9TJTS8M 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/P9TJTS8M Online_Linkage: https://www.sciencebase.gov/catalog/item/607df116d34e8564d67e3ae6 Larger_Work_Citation: Citation_Information: Originator: Theresa A. Fregoso Originator: Bruce E. Jaffe Originator: Amy C. Foxgrover Publication_Date: 2020 Title: High-resolution (1 m) digital elevation model (DEM) of San Francisco Bay, California, created using bathymetry data collected between 1999 and 2020 Edition: 2.0 Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P9TJTS8M 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/P9TJTS8M Online_Linkage: https://www.sciencebase.gov/catalog/item/5e0592d6e4b0b207aa094f2a Description: Abstract: A 1-m resolution, continuous surface, bathymetric digital elevation model (DEM) of the southern portion of San Francisco Bay, was constructed from bathymetric surveys collected from 2005 to 2020. In 2014 and 2015 the California Ocean Protection Council (OPC) contracted the collection of bathymetric surveys of large portions of San Francisco Bay. A total of 93 surveys were collected using a combination of multibeam and interferometric side-scan sonar systems. Of those 93 surveys, 75 consist of swaths of data ranging from 18- to just over 100-meters wide. These swaths were separated by data gaps ranging from 10- to just over 300-meters wide. The no-data areas required interpolation to create a continuous surface. The OPC surveys were combined with additional datasets collected by the United States Geological Survey (USGS), National Oceanic and Atmospheric Administration (NOAA), NOAA National Ocean Service (NOS), and the United States Army Corps of Engineers (USACE) to create a continuous, high-resolution digital elevation model (DEM). The creation of this DEM refines techniques developed by the USGS to create DEMs from historic bathymetric data, and allow for the creation of a modern-day bathymetric surface that can be compared to earlier surveys to delineate regions of sediment erosion and deposition. Purpose: These data were compiled using new techniques to create a high-resolution DEM of the southern portion of San Francisco Bay, which will be used to document and assess changes in seafloor morphology. These data are intended for science researchers, students, policy makers, and the general public. These data can be used with geographic information systems (GIS) or other software to identify elevations. These data are not intended to be used for navigational purposes. Supplemental_Information: Additional information about the USGS field activities from which some of these data were derived is available online at: https://cmgds.marine.usgs.gov/fan_info.php?fan=b105SF https://cmgds.marine.usgs.gov/fan_info.php?fan=S0111SF https://cmgds.marine.usgs.gov/fan_info.php?fan=2016-678-FA https://cmgds.marine.usgs.gov/fan_info.php?fan=2019-614-FA 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: 2005 Ending_Date: 2020 Currentness_Reference: publication date of source DEMs Status: Progress: In work Maintenance_and_Update_Frequency: As needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -122.392772 East_Bounding_Coordinate: -121.970645 North_Bounding_Coordinate: 37.762968 South_Bounding_Coordinate: 37.416934 Keywords: Theme: Theme_Keyword_Thesaurus: The National Map Collection Thesaurus Theme_Keyword: Digital Elevation Model (DEM) 1 meter Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: digital elevation models Theme_Keyword: bathymetry Theme_Keyword: topography Theme_Keyword: geographic information systems Theme_Keyword: geospatial datasets Theme_Keyword: single-beam echo sounder Theme_Keyword: multibeam sonar Theme_Keyword: GPS measurement 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: geographic information systems (GIS) Theme_Keyword: single-beam echo sounder Theme_Keyword: multibeam echo sounder Theme_Keyword: topographic mapping Theme_Keyword: Global Positioning System (GPS) observations Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: elevation Theme_Keyword: inlandWaters Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:607df116d34e8564d67e3ae6 Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: San Francisco Bay Place_Keyword: Alviso Slough Place_Keyword: Coyote Creek Place_Keyword: Dumbarton Bridge Place_Keyword: San Mateo Bridge 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 Browse_Graphic: Browse_Graphic_File_Name: https://www.sciencebase.gov/catalog/file/get/607df116d34e8564d67e3ae6?name=SouthSFBay_DEM_Mosaic_MLLW_1m.jpg&allowOpen=true Browse_Graphic_File_Description: Bathymetric map of the southern portion of San Francisco Bay (MLLW). Browse_Graphic_File_Type: JPEG Native_Data_Set_Environment: Microsoft Version 6.2 (Build 9200); Esri ArcGIS 10.8.1.14362(Build 9270) Service Pack N/A (Build N/A) Cross_Reference: Citation_Information: Originator: International Hydrographic Organization (IHO) Publication_Date: 2008 Title: IHO standards for hydrographic surveys (5th ed.) Online_Linkage: https://www.iho.int/iho_pubs/standard/S-44_5E.pdf Cross_Reference: Citation_Information: Originator: Environmental Systems Research Institute, Inc (ESRI) Publication_Date: 2015 Title: Topo to Raster help page Online_Linkage: http://desktop.arcgis.com/en/desktop/latest/tools/3d-analyst-toolbox/topo-to-raster.htm Cross_Reference: Citation_Information: Originator: Environmental Systems Research Institute, Inc (ESRI) Publication_Date: 2020 Title: Pixel Editor in ArcGIS Pro Online_Linkage: https://pro.arcgis.com/en/pro-app/latest/help/analysis/image-analyst/pixel-editor-in-arcgis-pro.htm Cross_Reference: Citation_Information: Originator: National Oceanic and Atmospheric Administration (NOAA) Publication_Date: 2019 Title: Vertical Datum Transformation (VDatum) Online_Linkage: https://vdatum.noaa.gov/welcome.html Cross_Reference: Citation_Information: Originator: United States Geological Survey (USGS) Publication_Date: 2007 Title: 2005 Hydrographic Survey of South San Francisco Bay, California Online_Linkage: 2005 Hydrographic Survey of South San Francisco Bay, California Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: No formal attribute accuracy tests were conducted. Logical_Consistency_Report: No formal logical consistency tests were conducted. Completeness_Report: Data set 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: Data are as accurate as source data used. No further tests were conducted, and no claims are made to positional accuracy. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Data are as accurate as source data used. No further tests were conducted, and no claims are made to vertical accuracy. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: Theresa A. Fregoso Publication_Date: 2021 Title: Footprints and producers of source data used to create the southern portion of the high-resolution (1 m) San Francisco Bay, California, digital elevation model (DEM) Geospatial_Data_Presentation_Form: Vector Digital Data Set 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/P9TJTS8M Type_of_Source_Media: Digital Resources Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2005 Ending_Date: 2020 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: Source DEMS Source_Contribution: Footprints of bathymetric source DEMS used to create high-resolution San Francisco Bay bathymetric surface. Process_Step: Process_Description: Using ArcGIS, the source DEMs were displayed and areas that would need further interpolation were identified. The lineage, vertical datum, and resolution of each DEM surface were noted for order of precedence when constructing the combined DEM and need for resampling or datum conversions. Using the ArcGIS Mosaic to New Raster tool, the surveys that were from the same sources, and were not continuous surfaces, were assembled into separate DEMs. Elevation contours were digitized across the DEMs to constrain the interpolation across data gaps in intervals of 20 centimeters across broader shallower areas (generally in water depths less than 4 m), and in intervals of 1 meter in deeper areas. The sections were converted from raster to points to use as inputs in the interpolation process. Using the ArcGIS Topo to Raster tool (ESRI 2015), the point data were used, along with the newly drawn contours, to interpolate continuous DEMs at a resolution of 1 meter, using the contours as the primary interpolation constraint. There were areas of multibeam data with varying resolutions, and in a different vertical datum from the rest of the data used in this project. The data were resampled to 1 meter using the resample tool in ArcGIS, and then converted to NAVD88 using NOAA’s VDATUM tool (https://vdatum.noaa.gov/). There were a few areas with data gaps that were filled using the Topo to Raster method from above. Once all data were in the same horizontal (UTM NAD83) and vertical (NAVD88) datums, the different DEMs were fitted together into a seamless DEM using the ArcGIS Mosaic to new Raster tool. In areas with obvious discrepancies between DEMs, edges were smoothed by clipping out a narrow gap between surveys using the pixel editor tool (ESRI 2020) to set the areas to no data, then filling in elevation holes. The final pieces were all put together using the Mosaic to new Raster tool, and VDATUM was again used to create versions in both Mean Lower Low Water (MLLW) and NAVD88. In 2004 NOAA created a specific NAVD88 to MLLW zones for the area of the 2005 USGS South Bay Survey. These zones have yet to be fully incorporated in the VDATUM grids. The NOAA change zones were used for the MLLW conversion in the regions of the 2005 USGS Survey. Vdatum was used for parts no included in the NOAA grid. The VDATUM tool did not have the full extents of the MLLW version available for conversion, so the pixel editor tool was used to interpolate based on the edges of the available data. Source_Used_Citation_Abbreviation: Source DEMS Process_Date: 20201214 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Row_Count: 38073 Column_Count: 36939 Vertical_Count: 1 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator Universal_Transverse_Mercator: UTM_Zone_Number: 10 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.9996 Longitude_of_Central_Meridian: -123.0 Latitude_of_Projection_Origin: 0.0 False_Easting: 500000.0 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: Meter Geodetic_Model: Horizontal_Datum_Name: D_NAD_1983_2011 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: Mean Lower Low Water (MLLW) 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: floating point Entity_Type_Definition: GeoTiff with elevation data associated with the digital elevation model (DEM) relative to MLLW. Cells with values of -3.4028231e+38 indicate no data. Entity_Type_Definition_Source: Producer defined Attribute: Attribute_Label: Value Attribute_Definition: Elevation relative to MLLW Attribute_Definition_Source: Producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -29.16707611084 Range_Domain_Maximum: 2.938999414444 Attribute_Units_of_Measure: meters Attribute_Measurement_Resolution: 0.01 Overview_Description: Entity_and_Attribute_Overview: DEM in meters using MLLW datum showing bathymetric elevations of the southern portion of San Francisco Bay, California. Entity_and_Attribute_Detail_Citation: The entity and attribute information were generated by the individual and/or agency identified as the originator of the data set. Please review the rest of the metadata record for additional details and information. Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - ScienceBase Contact_Address: Address_Type: mailing and physical Address: Denver Federal Center, Building 810, Mail Stop 302 City: Denver State_or_Province: CO Postal_Code: 80225 Country: US Contact_Voice_Telephone: 1-888-275-8747 Contact_Electronic_Mail_Address: sciencebase@usgs.gov Resource_Description: These data are available as a GeoTiff (SouthSFBay_DEM_Mosaic_MLLW_1m.tif) with accompanying files and 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: ArcGIS 10.8.1 Format_Information_Content: Zip file contains a GeoTiff version of the DEM with associated file, a browse graphic, and FGDC-compliant metadata. File_Decompression_Technique: Data can be unpacked using WinZip, or other zip decompression software. Transfer_Size: 1051 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/607df116d34e8564d67e3ae6 Network_Resource_Name: https://www.sciencebase.gov/catalog/item/607df116d34e8564d67e3ae6 Network_Resource_Name: https://doi.org/10.5066/P9TJTS8M Access_Instructions: Data can be downloaded using the Network_Resource_Name links. The first link begins a direct download of the DEM data, metadata, and a browse graphic. The second link points to the landing page for information about the MLLW version of the DEM for the southern portion of San Francisco Bay. The third link points to the landing page for the entire data release. Fees: None Technical_Prerequisites: These data can be viewed with ArcGIS software. Metadata_Reference_Information: Metadata_Date: 20210708 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