Carrie K. Bretz Rikk G. Kvitek Peter Dartnell Mercedes D. Erdey 2015 1.0 GeoTiff Data Series DS 781 Reston, VA U.S. Geological Survey https://www.sciencebase.gov/catalog/item/5548064be4b0a658d7954957 Nadine E. Golden 2013 database Data Series DS 781 Reston, VA U.S. Geological Survey https://pubs.usgs.gov/ds/781/ https://cmgds.marine.usgs.gov/data/csmp/OffshorePigeonPoint/data_catalog_OffshorePigeonPoint.html This part of DS 781 presents data for the acoustic-backscatter map of Offshore of Pigeon Point map area, California. Backscatter data are provided as three separate grids depending on mapping system. This metadata file refers to the data included in "BackscatterC_SWATH_OffshorePigeonPoint.zip," which is accessible from https://doi.org/10.5066/F7513W80. These data accompany the pamphlet and map sheets of Cochrane, G.R., Watt, J.T., Dartnell, P., Greene, H.G., Erdey, M.D., Dieter, B.E., Golden, N.E., Johnson, S.Y., Endris, C.A., Hartwell, S.R., Kvitek, R.G., Davenport, C.W., Krigsman, L.M., Ritchie, A.C., Sliter, R.W., Finlayson, D.P., and Maier, K.L. (G.R. Cochrane and S.A. Cochran, eds.), 2015, California State Waters Map Series—Offshore of Pigeon Point, California: U.S. Geological Survey Open-File Report 2015–1232, pamphlet 40 p., 10 sheets, scale 1:24,000, https://doi.org/10.3133/ofr20151232. The acoustic-backscatter map of the Offshore of Pigeon Point, California was generated from backscatter data collected by California State University, Monterey Bay (CSUMB), by Fugro Pelagos, and by the U.S. Geological Survey (USGS). Mapping was completed between 2006 and 2009, using a combination of 400-kHz Reson 7125 and 244-kHz Reson 8101 multibeam echosounders, as well as a 234-kHz SWATHplus bathymetric sidescan-sonar system. Within the final imagery, brighter tones indicate higher backscatter intensity, and darker tones indicate lower backscatter intensity. The intensity represents a complex interaction between the acoustic pulse and the seafloor, as well as characteristics within the shallow subsurface, providing a general indication of seafloor texture and composition. Backscatter intensity depends on the acoustic source level; the frequency used to image the seafloor; the grazing angle; the composition and character of the seafloor, including grain size, water content, bulk density, and seafloor roughness; and some biological cover. Harder and rougher bottom types such as rocky outcrops or coarse sediment typically return stronger intensities (high backscatter, lighter tones), whereas softer bottom types such as fine sediment return weaker intensities (low backscatter, darker tones). 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 seafloor features. 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. 2006 2009 ground condition Complete As needed -122.39 -122.19 37.10 36.94 USGS Metadata Identifier USGS:5548064be4b0a658d7954957 Global Change Master Directory (GCMD) Acoustic Reflectivity None U.S. Geological Survey USGS Coastal and Marine Hazards and Resources Program CMHRP Pacific Coastal and Marine Science Center PCMSC Fisheries Backscatter Intensity Seafloor Character ISO 19115 Topic Category geoscientificInformation environment oceans imageryBaseMapsEarthCover Data Categories for Marine Planning distributions physical habitats and geomorphology Marine Realms Information Bank (MRIB) keywords seabed sidescan sonar marine geophysics USGS Thesaurus geology bathymetry ecosystems multibeam sonar sonar methods sidescan sonar image mosaics marine geophysics sea-floor characteristics sea-floor acoustic reflectivity maps and atlases geospatial datasets Coastal and Marine Ecological Classification Standard (CMECS) Marine Nearshore Subtidal Marine Offshore Subtidal Transform Continental Margin Continental/Island Shelf Rock Substrate Unconsolidated Mineral Substrate Geographic Names Information System (GNIS) Pacific Ocean State of California Pigeon Point San Mateo County Ano Nuevo Coastal and Marine Ecological Classification Standard (CMECS) Northern California Ecoregion Coastal and Marine Ecological Classification Standard (CMECS) Substrate 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 and California State University Monterey Bay as the originator(s) of the dataset and in products derived from these data. U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

2885 Mission Street

Santa Cruz CA 95060-5792 US 831-427-4747 pcmsc_data@usgs.gov https://www.sciencebase.gov/catalog/file/get/5547e66ae4b0a658d79520c0?name=BackscatterC_Swath_OffshorePigeonPoint.jpg&allowOpen=true Acoustic backscatter imagery of offshore Pigeon Point. JPEG Microsoft Windows Server 2008 R2 Version 6.1 (Build 7601) Service Pack 1; ESRI ArcCatalog 10.0 Guy R. Cochrane Janet T. Watt Peter Dartnell H. Gary Greene Mercedes D. Erdey Bryan E. Dieter Nadine E. Golden Samuel Y. Johnson Charles A. Endris Stephen R. Hartwell Rikk G. Kvitek Clifton W. Davenport Lisa M. Krigsman Andrew C. Ritchie Ray W. Sliter David P. Finlayson Katherine L. Maier 2015 map Open-File Report 2015-1232 Reston, VA U.S. Geological Survey https://doi.org/10.3133/ofr20151232 Not applicable for raster data. Unspecified Complete Estimated to be no less than 2 m, owing to water depth and 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. Not applicable to acoustic-backscatter imagery. During the USGS mapping mission, GPS data with real-time-kinematic corrections were combined with measurements of vessel motion (heave, pitch, and roll) in a CodaOctopus F180 attitude-and-position system to produce a high-precision vessel-attitude packet. This packet was transmitted to the acquisition software in real time and combined with instantaneous sound-velocity measurements at the transducer head before each ping. The returned samples were projected to the seafloor using a ray-tracing algorithm that works with previously measured sound-velocity profiles. Statistical filters were applied to discriminate seafloor returns (soundings and backscatter intensity) from unintended targets in the water column. Finally, the soundings were converted into 2-m-resolution bathymetric-surface-model grids. The backscatter data were postprocessed using USGS software (D.P. Finlayson, written commun., 2011) that normalizes for time-varying signal loss and beam-directivity differences. Thus, the raw 16-bit backscatter data were gain-normalized to enhance the backscatter of the SWATHplus system. The resulting normalized-amplitude values were rescaled to 16-bit and gridded into GeoJPEGs using GRID Processor Software, then imported into a geographic information system (GIS) and converted to GRIDs. 2014 Pete Dartnell U.S. Geological Survey, Pacific Coastal and Marine Science Center Physical Scientist mailing and physical address

2885 Mission Street

Santa Cruz CA 95060-5792 USA (831) 460-7415 pdartnell@usgs.gov Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog. 20171005 U.S. Geological Survey Alan O. Allwardt Contractor -- Information Specialist mailing and physical address

2885 Mission Street

Santa Cruz CA 95060 831-460-7551 831-427-4748 aallwardt@usgs.gov Added keywords from Coastal and Marine Ecological Classification Standard (CMECS) to metadata. 20180426 U.S. Geological Survey Alan O. Allwardt Contractor -- Information Specialist mailing and physical address

2885 Mission Street

Santa Cruz CA 95060 831-460-7551 831-427-4748 aallwardt@usgs.gov Corrected author spelling in Larger Work section 20180622 Susan A Cochran U.S. Geological Survey, Pacific Coastal and Marine Science Center Geologist mailing and physical address

2885 Mission Street

Santa Cruz CA 95060-5792 USA (831) 460-7545 scochran@usgs.gov Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. 20201019 U.S. Geological Survey VeeAnn A. Cross Marine Geologist Mailing and Physical

384 Woods Hole Road

Woods Hole MA 02543-1598 508-548-8700 x2251 508-457-2310 vatnipp@usgs.gov Edits were made to bring the metadata up to current PCMSC standards including standardizing authors' names, adding a doi# link, correcting typos, refining keywords, and using current access and distribution liability statements. Point of Contact and Metadata Contact information sections were changed to static PCMSC contact information. No data were changed. The metadata available from a harvester may supersede metadata bundled within a download file. Users are advised to compare the metadata date of this file to any similar file to ensure they are using the most recent version. 20211101 U.S. Geological Survey Susan A. Cochran Geologist Mailing and Physical

2885 Mission Street

Santa Cruz CA 95060 831-460-7545 scochran@usgs.gov Raster Grid Cell 8890 8920 1 Universal Transverse Mercator 10 0.9996 -123.00000 0.00000 500000.0 0.00 coordinate pair 2.0 2.0 Meters WGS84 WGS84 6378137.00 298.257223563 Value BackscatterC [Swath] intensity value ESRI VALUE Backscatter intensity values ESRI 1.0 65535 Integers representing intensity values The SWATHPlus acoustic-backscatter grid was originally archived as an ESRI grid with the following attributes: >Cell size = 2.0 >Number of rows = 8890 >Number of columns = 8920 > >Data type = floating point > >Boundary >Xmin = 545580 >Xmax = 563420 >Ymin = 4103330 >Ymax = 4121110 > >Statistics >Minimum value = 9.88 >Maximum value = 65535 >Mean = 41000.46 >Standard deviation = 14135.95 > >Coordinate system description >Projection UTM >Zone 10 >Datum WGS84 >Units meter none U.S. Geological Survey mailing and physical address

345 Middlefield Rd

Menlo Park CA 94025-3561 USA (650) 329-4309 The .zip file (BackscatterC_SWATH_OffshorePigeonPoint.zip) includes the .tfw, .tif, .tif.aux.xml, and .tif.ovr files, as well as FGDC-compliant metadata for the BackscatterC [SWATH] data layer in the Offshore Pigeon Point region of California. 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. TIFF ArcMap (version 10.0, ESRI , 2011) Raster data layer is registered TIFF image in the UTM Zone 10 coordinate system with datum WGS84. The .zip file for the TIFF image includes the image (.tif), the world registration file (.tfw), and the text (.txt) and XML (.tif.xml) versions of the metadata for the BackscatterC [SWATH] data layer of Offshore Pigeon Point, California. WinZip 12.3 https://www.sciencebase.gov/catalog/file/get/5548064be4b0a658d7954957 https://cmgds.marine.usgs.gov/data/csmp/OffshorePigeonPoint/data_catalog_OffshorePigeonPoint.html https://doi.org/10.3133/ds781 The first link will begin a direct download of the data. The second link is a landing page on which all of the downloadable data for a particular region are listed. The third link is a landing page for the entire data catalog. none 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 an Esri ArcMap TIFF. Users should download the ArcGIS Project File, OffshorePigeonPointGIS.mxd.zip, a compressed (with the "zip" command) version of the ArcMap document (.mxd) that has all the data layers loaded in the table of contents for "Offshore Pigeon Point" and has all the data symbolized as on the data release map sheets. Download and save this ArcGIS project file, including all data layers, to the directory the user has created for this GIS. 20211101 U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

2885 Mission Street

Santa Cruz CA 95060-5792 US 831-427-4747 pcmsc_data@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 local time