Theresa A. Fregoso
Bruce E. Jaffe
Amy C. Foxgrover
20210708
Digital elevation model (DEM) of central San Francisco Bay, California, created using bathymetry data collected between 2009 and 2020 (MLLW)
Raster Digital Data Set
data release
DOI:10.5066/P9TJTS8M
Pacific Coastal and Marine Science Center, Santa Cruz, CA
U.S. Geological Survey
https://doi.org/10.5066/P9TJTS8M
https://www.sciencebase.gov/catalog/item/606b73efd34e3d0429b204d3
Theresa A. Fregoso
Bruce E. Jaffe
Amy C. Foxgrover
2020
High-resolution (1 m) digital elevation model (DEM) of San Francisco Bay, California, created using bathymetry data collected between 1999 and 2020
2.0
data release
DOI:10.5066/P9TJTS8M
Pacific Coastal and Marine Science Center, Santa Cruz, CA
U.S. Geological Survey
https://doi.org/10.5066/P9TJTS8M
A 1-m resolution, continuous surface, bathymetric digital elevation model (DEM) of the central 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’s 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.
These data were compiled using new techniques to create a high-resolution DEM of the central 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.
Additional information about the USGS field activity from which some of these data were derived is available online at:
https://cmgds.marine.usgs.gov/fan_info.php?fan=S310SF
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.
2009
2020
ground condition
As needed
-122.516735
-122.235097
37.994263
37.725137
The National Map Collection Thesaurus
Digital Elevation Model (DEM) 1 meter
USGS Thesaurus
digital elevation models
bathymetry
topography
geographic information systems
geospatial datasets
single-beam echo sounder
multibeam sonar
GPS measurement
Data Categories for Marine Planning
Bathymetry and Elevation
Marine Realms Information Bank (MRIB) keywords
geographic information systems (GIS)
single-beam echo sounder
multibeam echo sounder
topographic mapping
Global Positioning System (GPS) observations
ISO 19115 Topic Category
elevation
inlandWaters
USGS Metadata Identifier
USGS:606b73efd34e3d0429b204d3
Geographic Names Information System (GNIS)
San Francisco Bay
Golden Gate
Pacific Ocean
None
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.
U.S. Geological Survey, Pacific Coastal and Marine Science Center
PCMSC Science Data Coordinator
mailing and physical
2885 Mission Street
Santa Cruz
CA
95060
831-427-4747
pcmsc_data@usgs.gov
https://www.sciencebase.gov/catalog/file/get/606b73efd34e3d0429b204d3?name=CentralSFBay_DEM_Mosaic_MLLW_1m.jpg&allowOpen=true
Bathymetric map of the central portion of San Francisco Bay (MLLW).
JPEG
Microsoft Version 6.2 (Build 9200); Esri ArcGIS 10.8.1.14362(Build 9270) Service Pack N/A (Build N/A)
International Hydrographic Organization (IHO)
2008
IHO standards for hydrographic surveys (5th ed.)
https://www.iho.int/iho_pubs/standard/S-44_5E.pdf
Environmental Systems Research Institute, Inc (ESRI)
2015
Topo to Raster help page
http://desktop.arcgis.com/en/desktop/latest/tools/3d-analyst-toolbox/topo-to-raster.htm
Environmental Systems Research Institute, Inc (ESRI)
2020
Pixel Editor in ArcGIS Pro
https://pro.arcgis.com/en/pro-app/latest/help/analysis/image-analyst/pixel-editor-in-arcgis-pro.htm
National Oceanic and Atmospheric Administration (NOAA)
2019
Vertical Datum Transformation (VDatum)
https://vdatum.noaa.gov/welcome.html
No formal attribute accuracy tests were conducted.
No formal logical consistency tests were conducted.
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.
Data is as accurate as source data used. No further tests were conducted, and no claims are made to positional accuracy.
Data is as accurate as source data used. No further tests were conducted, and no claims are made to vertical accuracy.
Theresa A. Fregoso
2021
Footprints and producers of source data used to create central portion of the high-resolution (1 m) San Francisco Bay, California, digital elevation model (DEM)
Vector Digital Data Set
Pacific Coastal and Marine Science Center, Santa Cruz, CA
U.S. Geological Survey
https://doi.org/10.5066/P9TJTS8M
Digital Resources
2009
2020
ground condition
Source DEMS
Footprints of bathymetric source DEMS used to create high-resolution San Francisco Bay bathymetric surface.
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. 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 DEMS
20201214
Raster
Grid Cell
29697
24577
1
Universal Transverse Mercator
10
0.9996
-123.0
0.0
500000.0
0.0
row and column
1.0
1.0
Meter
D_NAD_1983_2011
GRS_1980
6378137.0
298.257222101
Mean Lower Low Water (MLLW)
0.01
meters
Explicit elevation coordinate included with horizontal coordinates
floating point
GeoTiff with elevation data associated with the digital elevation model (DEM) relative to MLLW. Cells with values of -3.4028231e+38 indicate no data.
Producer defined
Value
Elevation relative to MLLW
Producer defined
-110.10692596436
2.232547044754
meters
0.01
DEM in meters using MLLW datum showing bathymetric elevations of the central portion of San Francisco Bay, California.
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.
U.S. Geological Survey - ScienceBase
mailing and physical
Denver Federal Center, Building 810, Mail Stop 302
Denver
CO
80225
US
1-888-275-8747
sciencebase@usgs.gov
These data are available as a GeoTiff (CentralSFBay_DEM_Mosaic_MLLW_1m.tif) with accompanying files and FGDC-compliant metadata.
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.
geoTIFF
ArcGIS 10.8.1
Zip file contains a GeoTiff version of the DEM with associated file, a browse graphic, and FGDC-compliant metadata.
Data can be unpacked using WinZip, or other zip decompression software.
964.9
https://www.sciencebase.gov/catalog/file/get/606b73efd34e3d0429b204d3
https://www.sciencebase.gov/catalog/item/606b73efd34e3d0429b204d3
https://doi.org/10.5066/P9TJTS8M
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 central portion of San Francisco Bay. The third link points to the landing page for the entire data release.
None
These data can be viewed with ArcGIS software.
20210708
U.S. Geological Survey, Pacific Coastal and Marine Science Center
PCMSC Science Data Coordinator
mailing and physical
2885 Mission Street
Santa Cruz
CA
95060
831-427-4747
pcmsc_data@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998