{"accessLevel": "public", "bureauCode": ["010:12"], "contactPoint": {"@type": "vcard:Contact", "fn": "PCMSC Science Data Coordinator", "hasEmail": "mailto:pcmsc_data@usgs.gov"}, "description": "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  \"BackscatterB_7125_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\u2014Offshore of Pigeon Point, California: U.S. Geological Survey Open-File Report 2015\u20131232, pamphlet 40 p., 10 sheets, scale 1:24,000, https://doi.org/10.3133/ofr20151232.\nThe 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).", "distribution": [{"@type": "dcat:Distribution", "accessURL": "https://cmgds.marine.usgs.gov/data/csmp/OffshorePigeonPoint/data_catalog_OffshorePigeonPoint.html", "description": "Landing page for access to the data", "format": "XML", "mediaType": "application/http", "title": "Digital Data"}, {"@type": "dcat:Distribution", "description": "The metadata original format", "downloadURL": "https://data.usgs.gov/datacatalog/metadata/USGS.5548073be4b0a658d7954cf6.xml", "format": "XML", "mediaType": "text/xml", "title": "Original Metadata"}], "identifier": "http://datainventory.doi.gov/id/dataset/USGS_5548073be4b0a658d7954cf6", "keyword": ["sonar methods", "distributions", "imageryBaseMapsEarthCover", "Coastal and Marine Hazards and Resources Program", "multibeam sonar", "Ano Nuevo", "geospatial datasets", "seabed", "maps and atlases", "Pacific Ocean", "U.S. Geological Survey", "San Mateo County", "Acoustic Reflectivity", "Marine Nearshore Subtidal", "USGS", "CMHRP", "sea-floor acoustic reflectivity", "State of California", "Transform Continental Margin", "ecosystems", "sea-floor characteristics", "environment", "marine geophysics", "Northern California Ecoregion", "Marine Offshore Subtidal", "Seafloor Character", "Intensity", "Continental/Island Shelf", "USGS:5548073be4b0a658d7954cf6", "Fisheries", "image mosaics", "geology", "oceans", "sidescan sonar", "Pacific Coastal and Marine Science Center", "geoscientificInformation", "Rock Substrate", "bathymetry", "Backscatter", "Pigeon Point", "PCMSC", "Unconsolidated Mineral Substrate", "physical habitats and geomorphology"], "modified": "2021-11-01T00:00:00Z", "publisher": {"@type": "org:Organization", "name": "U.S. Geological Survey"}, "spatial": "-122.49, 37.07, -122.29, 37.23", "theme": ["geospatial"], "title": "BackscatterB [7125]--Offshore Pigeon Point, California"}