Metadata:
  Identification_Information:
    Citation:
      Citation_Information:
        Originator: Carrie K. Bretz
        Originator: Rikk G. Kvitek
        Originator: Peter Dartnell
        Originator: Mercedes D. Erdey
        Publication_Date: 2015
        Title: BackscatterA [8101]--Offshore Pigeon Point, California
        Edition: 1.0
        Geospatial_Data_Presentation_Form: GeoTiff
        Series_Information:
          Series_Name: Data Series
          Issue_Identification: DS 781
        Publication_Information:
          Publication_Place: Reston, VA
          Publisher: U.S. Geological Survey
        Online_Linkage: https://www.sciencebase.gov/catalog/item/55480a65e4b0a658d79557a7
        Larger_Work_Citation:
          Citation_Information:
            Originator: Nadine E. Golden
            Publication_Date: 2013
            Title: California State Waters Map Series Data Catalog
            Geospatial_Data_Presentation_Form: database
            Series_Information:
              Series_Name: Data Series
              Issue_Identification: DS 781
            Publication_Information:
              Publication_Place: Reston, VA
              Publisher: U.S. Geological Survey
            Online_Linkage: https://pubs.usgs.gov/ds/781/
            Online_Linkage: https://cmgds.marine.usgs.gov/data/csmp/OffshorePigeonPoint/data_catalog_OffshorePigeonPoint.html
    Description:
      Abstract:
        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  "BackscatterA_8101_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 map area, 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 (CSUMB) and 244-kHz Reson 8101 (FUGRO) multibeam echosounders, as well as a 234-kHz SWATHplus bathymetric sidescan-sonar system (USGS). These mapping missions combined to collect backscatter data from about the 10-m isobath to beyond the 3-nautical-mile limit of California's State Waters. 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).
      Purpose: 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.
      Supplemental_Information:
        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: 2006
          Ending_Date: 2009
      Currentness_Reference: ground condition
    Status:
      Progress: Complete
      Maintenance_and_Update_Frequency: As needed
    Spatial_Domain:
      Bounding_Coordinates:
        West_Bounding_Coordinate: -122.49
        East_Bounding_Coordinate: -122.29
        North_Bounding_Coordinate: 37.23
        South_Bounding_Coordinate: 37.07
    Keywords:
      Theme:
        Theme_Keyword_Thesaurus: USGS Metadata Identifier
        Theme_Keyword: USGS:55480a65e4b0a658d79557a7
      Theme:
        Theme_Keyword_Thesaurus: Global Change Master Directory (GCMD)
        Theme_Keyword: Acoustic Reflectivity
      Theme:
        Theme_Keyword_Thesaurus: None
        Theme_Keyword: U.S. Geological Survey
        Theme_Keyword: USGS
        Theme_Keyword: Coastal and Marine Hazards and Resources Program
        Theme_Keyword: CMHRP
        Theme_Keyword: Pacific Coastal and Marine Science Center
        Theme_Keyword: PCMSC
        Theme_Keyword: Fisheries
        Theme_Keyword: Backscatter
        Theme_Keyword: Intensity
        Theme_Keyword: Seafloor Character
      Theme:
        Theme_Keyword_Thesaurus: ISO 19115 Topic Category
        Theme_Keyword: geoscientificInformation
        Theme_Keyword: environment
        Theme_Keyword: oceans
        Theme_Keyword: imageryBaseMapsEarthCover
      Theme:
        Theme_Keyword_Thesaurus: Data Categories for Marine Planning
        Theme_Keyword: distributions
        Theme_Keyword: physical habitats and geomorphology
      Theme:
        Theme_Keyword_Thesaurus: Marine Realms Information Bank (MRIB) keywords
        Theme_Keyword: seabed
        Theme_Keyword: sidescan sonar
        Theme_Keyword: marine geophysics
      Theme:
        Theme_Keyword_Thesaurus: USGS Thesaurus
        Theme_Keyword: geology
        Theme_Keyword: bathymetry
        Theme_Keyword: ecosystems
        Theme_Keyword: multibeam sonar
        Theme_Keyword: sonar methods
        Theme_Keyword: sidescan sonar
        Theme_Keyword: image mosaics
        Theme_Keyword: marine geophysics
        Theme_Keyword: sea-floor characteristics
        Theme_Keyword: sea-floor acoustic reflectivity
        Theme_Keyword: maps and atlases
        Theme_Keyword: geospatial datasets
      Theme:
        Theme_Keyword_Thesaurus: Coastal and Marine Ecological Classification Standard (CMECS)
        Theme_Keyword: Marine Nearshore Subtidal
        Theme_Keyword: Marine Offshore Subtidal
        Theme_Keyword: Transform Continental Margin
        Theme_Keyword: Continental/Island Shelf
        Theme_Keyword: Rock Substrate
        Theme_Keyword: Unconsolidated Mineral Substrate
      Place:
        Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)
        Place_Keyword: Pacific Ocean
        Place_Keyword: State of California
        Place_Keyword: Pigeon Point
        Place_Keyword: San Mateo County
        Place_Keyword: Ano Nuevo
      Place:
        Place_Keyword_Thesaurus: Coastal and Marine Ecological Classification Standard (CMECS)
        Place_Keyword: Northern California Ecoregion
      Stratum:
        Stratum_Keyword_Thesaurus: Coastal and Marine Ecological Classification Standard (CMECS)
        Stratum_Keyword: Substrate
    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 and California State University Monterey Bay as the originator(s) of the dataset and in products derived from these data.
    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: 95060-5792
          Country: US
        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/5547e66ae4b0a658d79520c0?name=BackscatterA_8101_OffshorePigeonPoint.jpg&allowOpen=true
      Browse_Graphic_File_Description: Acoustic backscatter imagery of offshore Pigeon Point.
      Browse_Graphic_File_Type: JPEG
    Native_Data_Set_Environment: Microsoft Windows Server 2008 R2 Version 6.1 (Build 7601) Service Pack 1; ESRI ArcCatalog 10.0
    Cross_Reference:
      Citation_Information:
        Originator: Guy R. Cochrane
        Originator: Janet T. Watt
        Originator: Peter Dartnell
        Originator: H. Gary Greene
        Originator: Mercedes D. Erdey
        Originator: Bryan E. Dieter
        Originator: Nadine E. Golden
        Originator: Samuel Y. Johnson
        Originator: Charles A. Endris
        Originator: Stephen R. Hartwell
        Originator: Rikk G. Kvitek
        Originator: Clifton W. Davenport
        Originator: Lisa M. Krigsman
        Originator: Andrew C. Ritchie
        Originator: Ray W. Sliter
        Originator: David P. Finlayson
        Originator: Katherine L. Maier
        Publication_Date: 2015
        Title: California State Waters Map Series--Offshore of Pigeon Point, California
        Geospatial_Data_Presentation_Form: map
        Series_Information:
          Series_Name: Open-File Report
          Issue_Identification: 2015-1232
        Publication_Information:
          Publication_Place: Reston, VA
          Publisher: U.S. Geological Survey
        Online_Linkage: https://doi.org/10.3133/ofr20151232
  Data_Quality_Information:
    Attribute_Accuracy:
      Attribute_Accuracy_Report: Not applicable for raster data.
    Logical_Consistency_Report: Unspecified
    Completeness_Report: Complete
    Positional_Accuracy:
      Horizontal_Positional_Accuracy:
        Horizontal_Positional_Accuracy_Report: 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.
      Vertical_Positional_Accuracy:
        Vertical_Positional_Accuracy_Report: Not applicable to acoustic-backscatter imagery.
    Lineage:
      Process_Step:
        Process_Description: During the mapping missions, an Applanix position and motion compensation system (POS/MV) was used to accurately position the vessel during data collection, and it also accounted for vessel motion such as heave, pitch, and roll (position accuracy, +/-2 m; pitch, roll, and heading accuracy, +/-0.02 degrees; heave accuracy, +/-5 percent, or 5 cm). KGPS altitude data (Fugro Pelagos, StarFix HP & XP units; CSUMB, NavCom 2050) were used to account for tide cycle fluctuations and sound velocity profiles were collected with an Applied Microsystems SVPlus sound velocimeter. Soundings were corrected for vessel motion using the Applanix POS/MV data, for variations in water-column sound velocity using the AM SVPlus data, and for variations in water height (tides) using vertical-position data from the KGPS receivers. Processing and mosaicking of Reson 8101 trace data were completed using GEOCODER Version 3.2 level 1 (created by Luciano Fonseca; Fugro Pelagos Modified Test Release 16). Within Geocoder, the backscatter intensities were radiometrically corrected (including despeckling and angle varying gain adjustments) and the position of each acoustic sample was geometrically corrected for slant-range and georeferenced to UTM Zone 10 N, WGS1984 datum. After the lines were imported, they were mosaicked into a 1m resolution image.  Overlap between parallel lines was resolved using a priority table based on the distance of each sample from the ship track, with samples closest to- and furthest from- the ship track given the lowest priority. An anti-aliasing algorithm was also applied.
        Process_Date: 2006
        Process_Contact:
          Contact_Information:
            Contact_Person_Primary:
              Contact_Person: Carrie Bretz
              Contact_Organization: Seafloor Mapping Lab, California State University Monterey Bay
            Contact_Position: Projects Manager, GIS; Metadata Supervisor
            Contact_Address:
              Address_Type: mailing and physical address
              Address: 100 Campus Center, Bldg 13
              City: Seaside
              State_or_Province: CA
              Postal_Code: 93955
              Country: USA
            Contact_Voice_Telephone: (831) 582-4197
            Contact_Electronic_Mail_Address: carrie_bretz@csumb.edu
      Process_Step:
        Process_Description: California Seafloor Mapping Project 1- and 2-m resolution backscatter imagery (CSMP survey blocks CC-09, CC-10, and CC-11) within this map were downloaded from California State University, Monterey Bay, Seafloor Mapping Lab (https://seafloor.otterlabs.org/SFMLwebDATA.htm) and converted to grids. Backscatter grids of similar mapping systems were merged in a GIS and clipped to the boundary of the map area. Grids from different mapping systems were not merged together due to different mapping frequencies and processing techniques.
        Process_Date: 2014
        Process_Contact:
          Contact_Information:
            Contact_Person_Primary:
              Contact_Person: Pete Dartnell
              Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center
            Contact_Position: Physical Scientist
            Contact_Address:
              Address_Type: mailing and physical address
              Address: 2885 Mission Street
              City: Santa Cruz
              State_or_Province: CA
              Postal_Code: 95060-5792
              Country: USA
            Contact_Voice_Telephone: (831) 460-7415
            Contact_Electronic_Mail_Address: pdartnell@usgs.gov
      Process_Step:
        Process_Description: Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog.
        Process_Date: 20171005
        Process_Contact:
          Contact_Information:
            Contact_Organization_Primary:
              Contact_Organization: U.S. Geological Survey
              Contact_Person: Alan O. Allwardt
            Contact_Position: Contractor -- Information Specialist
            Contact_Address:
              Address_Type: mailing and physical address
              Address: 2885 Mission Street
              City: Santa Cruz
              State_or_Province: CA
              Postal_Code: 95060
            Contact_Voice_Telephone: 831-460-7551
            Contact_Facsimile_Telephone: 831-427-4748
            Contact_Electronic_Mail_Address: aallwardt@usgs.gov
      Process_Step:
        Process_Description: Added keywords from Coastal and Marine Ecological Classification Standard (CMECS) to metadata.
        Process_Date: 20180426
        Process_Contact:
          Contact_Information:
            Contact_Organization_Primary:
              Contact_Organization: U.S. Geological Survey
              Contact_Person: Alan O. Allwardt
            Contact_Position: Contractor -- Information Specialist
            Contact_Address:
              Address_Type: mailing and physical address
              Address: 2885 Mission Street
              City: Santa Cruz
              State_or_Province: CA
              Postal_Code: 95060
            Contact_Voice_Telephone: 831-460-7551
            Contact_Facsimile_Telephone: 831-427-4748
            Contact_Electronic_Mail_Address: aallwardt@usgs.gov
      Process_Step:
        Process_Description: Corrected author spelling in Larger Work section
        Process_Date: 20180622
        Process_Contact:
          Contact_Information:
            Contact_Person_Primary:
              Contact_Person: Susan A Cochran
              Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center
            Contact_Position: Geologist
            Contact_Address:
              Address_Type: mailing and physical address
              Address: 2885 Mission Street
              City: Santa Cruz
              State_or_Province: CA
              Postal_Code: 95060-5792
              Country: USA
            Contact_Voice_Telephone: (831) 460-7545
            Contact_Electronic_Mail_Address: scochran@usgs.gov
      Process_Step:
        Process_Description: Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed.
        Process_Date: 20201019
        Process_Contact:
          Contact_Information:
            Contact_Organization_Primary:
              Contact_Organization: U.S. Geological Survey
              Contact_Person: VeeAnn A. Cross
            Contact_Position: Marine Geologist
            Contact_Address:
              Address_Type: Mailing and Physical
              Address: 384 Woods Hole Road
              City: Woods Hole
              State_or_Province: MA
              Postal_Code: 02543-1598
            Contact_Voice_Telephone: 508-548-8700 x2251
            Contact_Facsimile_Telephone: 508-457-2310
            Contact_Electronic_Mail_Address: vatnipp@usgs.gov
      Process_Step:
        Process_Description: 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.
        Process_Date: 20211101
        Process_Contact:
          Contact_Information:
            Contact_Organization_Primary:
              Contact_Organization: U.S. Geological Survey
              Contact_Person: Susan A. Cochran
            Contact_Position: Geologist
            Contact_Address:
              Address_Type: Mailing and Physical
              Address: 2885 Mission Street
              City: Santa Cruz
              State_or_Province: CA
              Postal_Code: 95060
            Contact_Voice_Telephone: 831-460-7545
            Contact_Electronic_Mail_Address: scochran@usgs.gov
  Spatial_Data_Organization_Information:
    Direct_Spatial_Reference_Method: Raster
    Raster_Object_Information:
      Raster_Object_Type: Grid Cell
      Row_Count: 8890
      Column_Count: 8890
      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: -123.00000
              Latitude_of_Projection_Origin: 0.00000
              False_Easting: 500000.0
              False_Northing: 0.00
        Planar_Coordinate_Information:
          Planar_Coordinate_Encoding_Method: coordinate pair
          Coordinate_Representation:
            Abscissa_Resolution: 2.0
            Ordinate_Resolution: 2.0
          Planar_Distance_Units: Meters
      Geodetic_Model:
        Horizontal_Datum_Name: WGS84
        Ellipsoid_Name: WGS84
        Semi-major_Axis: 6378137.00
        Denominator_of_Flattening_Ratio: 298.257223563
  Entity_and_Attribute_Information:
    Detailed_Description:
      Entity_Type:
        Entity_Type_Label: Value
        Entity_Type_Definition: BackscatterA [8101] intensity value
        Entity_Type_Definition_Source: ESRI
      Attribute:
        Attribute_Label: Rowid
        Attribute_Definition: Internal feature number.
        Attribute_Definition_Source: ESRI
        Attribute_Domain_Values:
          Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated.
      Attribute:
        Attribute_Label: VALUE
        Attribute_Definition: Backscatter intensity values
        Attribute_Definition_Source: ESRI
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 39.0
            Range_Domain_Maximum: 254.0
            Attribute_Units_of_Measure: Integers representing intensity values
      Attribute:
        Attribute_Label: COUNT
        Attribute_Definition: The number of pixels (2m x 2m size grid cell) represented in each intensity value (see Attribute: VALUE).
        Attribute_Definition_Source: ESRI
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 530
            Range_Domain_Maximum: 365204
            Attribute_Units_of_Measure: Integers
    Overview_Description:
      Entity_and_Attribute_Overview:
        The merged Reson 8101 acoustic-backscatter grid was originally archived as an ESRI grid with the following attributes:
        >Cell size = 2.0
        >Number of rows = 8885
        >Number of columns = 8880
        >
        >Data type = floating point
        >
        >Boundary
        >Xmin = 545630
        >Xmax = 563390
        >Ymin = 4103330
        >Ymax = 4121100
        >
        >Statistics
        >Minimum value = 39
        >Maximum value = 254
        >Mean = 123.38
        >Standard deviation = 32.20
        >
        >Coordinate system description
        >Projection  UTM
        >Zone  10
        >Datum  WGS84
        >Units  meter
      Entity_and_Attribute_Detail_Citation: none
  Distribution_Information:
    Distributor:
      Contact_Information:
        Contact_Organization_Primary:
          Contact_Organization: U.S. Geological Survey
        Contact_Address:
          Address_Type: mailing and physical address
          Address: 345 Middlefield Rd
          City: Menlo Park
          State_or_Province: CA
          Postal_Code: 94025-3561
          Country: USA
        Contact_Voice_Telephone: (650) 329-4309
    Resource_Description: The .zip file (BackscatterA_8101_OffshorePigeonPoint.zip) includes the .tfw, .tif, .tif.aux.xml, and .tif.ovr files, as well as FGDC-compliant metadata for the BackscatterA [8101] data layer in the Offshore Pigeon Point region of California.
    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: TIFF
          Format_Version_Number: ArcMap (version 10.0, ESRI , 2011)
          Format_Specification: Raster data layer is registered TIFF image in the UTM Zone 10 coordinate system with datum WGS84.
          Format_Information_Content: 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 BackscatterA [8101] data layer of Offshore Pigeon Point, California.
          File_Decompression_Technique: WinZip
          Transfer_Size: 22.4
        Digital_Transfer_Option:
          Online_Option:
            Computer_Contact_Information:
              Network_Address:
                Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/55480a65e4b0a658d79557a7
                Network_Resource_Name: https://cmgds.marine.usgs.gov/data/csmp/OffshorePigeonPoint/data_catalog_OffshorePigeonPoint.html
                Network_Resource_Name: https://doi.org/10.3133/ds781
            Access_Instructions: 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.
      Fees: none
    Technical_Prerequisites: 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.
  Metadata_Reference_Information:
    Metadata_Date: 20211101
    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: 95060-5792
          Country: US
        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
    Metadata_Time_Convention: local time
