Archive of Single-Beam Bathymetry Data Collected from Select Areas in Weeks Bay and Weeks Bayou, Southwest Louisiana, January 2013

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What does this data set describe?

Title:
Archive of Single-Beam Bathymetry Data Collected from Select Areas in Weeks Bay and Weeks Bayou, Southwest Louisiana, January 2013
Abstract:
A team of scientists from the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center (SPCMSC), collected 92-line-kilometers (km) of dual-frequency single-beam bathymetry data in the tidal creeks, bayous, and coastal areas near Weeks Bay, southwest Louisiana. Limited bathymetry data exist for these tidally- and meteorologically- influenced shallow-water estuarine environments. In order to reduce the present knowledge gap, the objectives of this study were to (1) develop methods for regional inland bathymetry mapping and monitoring, (2) test an inland bathymetry mapping system, in pilot locations, for the purpose of integrating multiple elevation (aerial and terrestrial lidar) and bathymetry datasets, (3) implement inland bathymetry mapping and monitoring in highly focused sites, and (4) evaluate changes in bathymetry and channel-fill sediment storage. This report contains single-beam bathymetric data collected between January 14 and 18, 2013(USGS Field Activity Number 13CCT01). Data were collected from the R/V Mako (5-m vessel) in water depths that ranged from <1 m to 7.7 m. Locations of data collection ranged from open-bay systems to narrow inland tidal creeks. Do not use these data for navigational purposes.
Supplemental_Information:
The USGS Saint Petersburg Coastal and Marine Science Center (SPCMSC) - St. Petersburg, Fla., assigns a unique identifier to each cruise or field activity. For example, 13CCT01 tells us the data were collected in 2013 during the first field activity for that project in that calendar year. Refer to http://walrus.wr.usgs.gov/infobank/programs/html/definition/activity.html for a detailed description of the method used to assign the cruise ID. This data series covers four geographic areas located within the Weeks Bay and Weeks Bayou areas of southwest Louisiana. The four areas have been given the following names: Port Channel North, Port Channel South, Weeks Bayou, and Shark Island Bayou, please refer to <http://pubs.usgs.gov/ds/0835/images/WEEKSBAY_LocationMap_large.jpg>.
  1. How might this data set be cited?
    DeWitt, Nancy T., Reich, Christopher D., Smith, Christopher G., and Reynolds, B.J., 2014, Archive of Single-Beam Bathymetry Data Collected from Select Areas in Weeks Bay and Weeks Bayou, Southwest Louisiana, January 2013: U.S. Geological Survey Data Series 835, U.S. Geolgical Survey, Saint Petersburg, Fla..

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -91.857464
    East_Bounding_Coordinate: -91.790870
    North_Bounding_Coordinate: 29.863384
    South_Bounding_Coordinate: 29.761927
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 14-Jan-2013
    Ending_Date: 18-Jan-2013
    Currentness_Reference:
    data collection interval
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: Tabular, vector, and raster digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Raster data set. It contains the following raster data types:
      • Dimensions 176 - 245 x 64 - 292 x 1, type Pixel
    2. What coordinate system is used to represent geographic features?
      The map projection used is Transverse Mercator.
      Projection parameters:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -87.0
      Latitude_of_Projection_Origin: 0.0
      False_Easting: 500000.0
      False_Northing: 0.0
      Planar coordinates are encoded using row and column
      Abscissae (x-coordinates) are specified to the nearest 10
      Ordinates (y-coordinates) are specified to the nearest 10
      Planar coordinates are specified in meters
      The horizontal datum used is D WGS 1984.
      The ellipsoid used is WGS 1984.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: Ellipsoid Height
      Depth_Resolution: 7.37
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates
  7. How does the data set describe geographic features?
    Port_Channel_North_2013_Bathy_SingleBeam_ITRF00_xyz.txt, Port_Channel_South_2013_Bathy_SingleBeam_ITRF00_xyz.txt, Weeks_Bayou_2013_Bathy_SingleBeam_ITRF00_xyz.txt, and Shark_Island_Bayou_2013_Bathy_SingleBeam_ITRF00_xyz.txt.
    Post-processed, area-specific x,y,z singlebeam bathymetry data in ASCII text format (Source: Esri ArcGIS 10.1)
    FID
    Internal feature number (Source: Esri ArcGIS 10.1) Sequential unique whole numbers that are automatically generated
    ITRF00_X
    The X or easting horizontal coordinate referenced to International Terrestrial Reference frame of 2000 (ITRF00) which is equal to WGS84 (G1150) (Source: CARIS HIPS and SIPS v. 8.0)
    Range of values
    Minimum:610403.451
    Maximum:616799.186
    Units:meters
    ITRF00_Y
    The Y or northing horizontal coordinate referenced to International Terrestrial Reference frame of 2000 (ITRF00) which is equal to WGS84 (G1150) (Source: CARIS HIPS and SIPS v. 8.0)
    Range of values
    Minimum:3292985.476
    Maximum:3304207.975
    Units:meters
    ITRF00_Lat
    The latitude coordinate referenced to International Terrestrial Reference frame of 2000 (ITRF00) which is equal to WGS84 (G1150) (Source: CARIS HIPS and SIPS v. 8.0)
    Range of values
    Minimum:29.845421
    Maximum:29.863222
    Units:decimal degrees
    ITRF00_Lon
    The longitude coordinate referenced to International Terrestrial Reference frame of 2000 (ITRF00) which is equal to WGS84 (G1150) (Source: CARIS HIPS and SIPS v. 8.0)
    Range of values
    Minimum:-91.839229
    Maximum:-91.820947
    Units:decimal degrees
    Year
    Calendar year of the survey (Source: U.S. Geological Survey) 2013
    DOY
    DOY is an acronym for day of year (Source: U.S. Geological Survey)
    Range of values
    Minimum:015
    Maximum:017
    Units:day
    Adjusted_m
    During the QA/QC process, if the elevation needed to be adjusted, this is the value in meters that was added to the elevation value in the ELEV attribute column. (Source: U.S. Geological Survey)
    Range of values
    Minimum:-0.30
    Maximum:+0.50
    Units:meters
    ABS_Adj
    This is the absolute value in meters of the Adjusted_m attribute column. (Source: U.S. Geological Survey)
    Range of values
    Minimum:0.00
    Maximum:0.50
    Units:meters
    ELEV
    The ellipsoid height in International Terrestrial Reference frame of 2000 (ITRF00) which is equal to WGS84 (G1150) (Source: CARIS HIPS and SIPS v. 8.0)
    Range of values
    Minimum:-35.485
    Maximum:-30.922
    Units:meters
    RASTERVAL
    A comparison of the DEM surface and the original x,y,z point data. These values were extracted using Esri ArcGIS version 10.1 Spatial Analyst extract values to points tool. (Source: Esri ArcGIS 10.1)
    Range of values
    Minimum:-9999
    Maximum:-31.182
    Units:meters
    Error
    This is the difference between the attribute ELEV value minus the attribute RASTERVAL value. (Source: Esri ArcGIS 10.1)
    Range of values
    Minimum:-3.10
    Maximum:9968.008
    Units:meters
    DataType
    A three letter acronym representing the type of bathymetric data. (Source: U.S. Geological Survey)
    ValueDefinition
    SBBSBB is the acronym for singlebeam bathymetry
    Entity_and_Attribute_Overview:
    Post-processed, area-specific x,y,z singlebeam bathymetry data in ASCII text format. The x and y coordinates are referenced to the International Terrestrial Reference frame of 2000 (ITRF00) which is equal to WGS84 (G1150). The and the z values are ellipsoid height also referenced to ITRF00.
    Entity_and_Attribute_Detail_Citation: http://pubs.usgs.gov/ds/0835/
    Port_Channel_North_2013_Bathy_SingleBeam_Error.shp, Port_Channel_South_2013_Bathy_SingleBeam_Error.shp, Weeks_Bayou_2013_Bathy_SingleBeam_Error.shp, Shark_Island_Bayou_2013_Bathy_SingleBeam_Error.shp
    These shapefiles are a visual, color-coded, spatial representation of the error difference between the DEM and the original x,y,z values. (Source: Esri ArcGIS 10.1)
    FID
    Internal feature number (Source: Esri ArcGIS 10.1) Sequential unique whole numbers that are automatically generated
    SHAPE
    Point Feature Geometry (Source: Esri ArcGIS 10.1) Point ZM defining the features.
    ITRF00_Y
    The Y or northing horizontal coordinate referenced to International Terrestrial Reference frame of 2000 (ITRF00) which is equal to WGS84 (G1150) (Source: CARIS HIPS and SIPS version 8.0)
    Range of values
    Minimum:3292975.476
    Maximum:3304212.931
    Units:meters
    ITRF00_X
    The X or easting horizontal coordinate referenced to International Terrestrial Reference frame of 2000 (ITRF00) which is equal to WGS84 (G1150) (Source: CARIS HIPS and SIPS version 8.0)
    Range of values
    Minimum:610393.451
    Maximum:616807.105
    Units:meters
    ITRF00_Lat
    The latitude coordinate in decimal degrees and referenced to International Terrestrial Reference frame of 2000 (ITRF00) which is equal to WGS84 (G1150) (Source: CARIS HIPS and SIPS version 8.0)
    Range of values
    Minimum:29.761963
    Maximum:29.863222
    Units:decimal degrees
    ITRF00_Lon
    The longitude coordinate in decimal degrees and referenced to International Terrestrial Reference frame of 2000 (ITRF00) which is equal to WGS84 (G1150) (Source: CARIS HIPS and SIPS version 8.0)
    Range of values
    Minimum:-91.821276
    Maximum:-91.84217
    Units:decimal degrees
    Error
    This is the difference between the attribute ELEV value minus the attribute RASTERVAL value. (Source: Esri ArcGIS 10.1)
    Range of values
    Minimum:-3.22
    Maximum:9971.17
    Units:meters
    ELEV
    The ellipsoid height in International Terrestrial Reference frame of 2000 (ITRF00) which is equal to WGS84 (G1150) (Source: CARIS HIPS AND SIPS version 8.0)
    Range of values
    Minimum:-35.853
    Maximum:-27.83
    Units:meters
    RASTERVAL
    A comparison of the DEM surface and the original x,y,z point data. These values were extracted using Esri ArcGIS version 10.1 Spatial Analyst extract values to points tool. (Source: Esri ArcGIS 10.1)
    Range of values
    Minimum:-9999
    Maximum:-31.182
    Units:meters
    Entity_and_Attribute_Overview:
    These shapefiles are a visual, color-coded, spatial representation of the error difference between the DEM and the original sounding values. The shapefile was created in ArcMap version 10.1. Additionally each shapefile was saved as a Esri's ArcGIS layer file (.lyr) and placed within the respective GIS project folder. These files are located within their respective folders located in the Data Downloads Folder.
    Entity_and_Attribute_Detail_Citation: http://pubs.usgs.gov/ds/0835/
    Port_Channel_North_2013_Bathy_SingleBeam_tracklines.shp, Port_Channel_South_2013_Bathy_SingleBeam_tracklines.shp, Weeks_Bayou_2013_Bathy_SingleBeam_tracklines.shp, Shark_Island_Bayou_2013_Bathy_SingleBeam_tracklines.shp
    These are the shapefiles of the ship navigation as recorded using HYPACK version 10. (Source: Esri ArcGIS 10.1)
    FID
    Internal feature number (Source: Esri ArcGIS 10.1) Sequential unique whole numbers that are automatically generated
    SHAPE
    Feature Geometry (Source: Esri ArcGIS 10.1) Polyline ZM defining the features.
    HypackLine
    Name of trackline from acquisition and post-processing (Source: U.S. Geological Survey)
    Formal codeset
    Codeset Name:###_####
    Codeset Source:First three numbers represent the number of the line and the last four numbers represent the time at which the line was acquired.
    Length_m
    Length of the trackline surveyed in meters (Source: U.S. Geological Survey)
    Range of values
    Minimum:2.93
    Maximum:24388.76
    Units:meters
    Year
    The year the trackline was surveyed (Source: U.S. Geological Survey) 2013
    Boat
    The survey platform used to collect the tracklines (Source: U.S. Geological Survey)
    ValueDefinition
    17makoRV Mako - 17 foot
    Entity_and_Attribute_Overview:
    These are the polyline shapefiles of the ship navigation as recorded using HYPACK version 10. The shapefiles were created in ArcMap version 10.1. Additionally each shapefile was saved as a Esri's ArcGIS layer file (.lyr) with the same filename. These files are located within their respective folders located in the Data Downloads Folder.
    Entity_and_Attribute_Detail_Citation: http://pubs.usgs.gov/ds/0835/
    Port_Channel_North_2013_Bathy_SingleBeam_NAD83_NAVD88_GEOID12A_xyz.txt, Port_Channel_South_2013_Bathy_SingleBeam_NAD83_NAVD88_GEOID12A_xyz.txt, Weeks_Bayou_2013_Bathy_SingleBeam_NAD83_NAVD88_GEOID12A_xyz.txt, Shark_Island_Bayou_2013_Bathy_SingleBeam_NAD83_NAVD88_GEOID12A_xyz.txt
    Post-processed, area-specific x,y,z singlebeam bathymetry data in ASCII text format. The X and Y coordinates are reference to NAD83 (CORS96) UTM Zone 15N, and the Z values are referenced to NAVD88 orthometric height. (Source: Esri ArcGIS 10.1)
    FID
    Internal feature number (Source: Esri ArcGIS 10.1) Sequential whole numbers automatically generated.
    NAD83_X
    The X or easting horizontal coordinate referenced North American Datum 1983 with respect to Geoid 12A (Source: VDatum v. 3.2)
    Range of values
    Minimum:610403.451
    Maximum:616799.186
    Units:meters
    NAD83_Y
    The Y or northing horizontal coordinate referenced North American Datum 1983 with respect to Geoid 12A (Source: VDatum v. 3.2)
    Range of values
    Minimum:3292985.476
    Maximum:3304207.975
    Units:meters
    NAVD88G12A
    The elevations as orthometric heights in North American Vertical Datum 1988 (NAVD88) with respect to GEOID12A (Source: VDatum v. 3.2)
    Range of values
    Minimum:-8.11
    Maximum:-0.64
    Units:meters
    DataType
    A three letter acronym representing the type of bathymetric data. (Source: U.S. Geological Survey)
    ValueDefinition
    SBBSBB is the acronym for single-beam bathymetry
    Year
    Calendar year of the survey (Source: U.S. Geological Survey) 2013
    DOY
    DOY is an acronym for day of year (Source: U.S. Geological Survey)
    Range of values
    Minimum:015
    Maximum:017
    Units:day
    Entity_and_Attribute_Overview:
    Post-processed, area-specific x,y,z single-beam bathymetry data in ASCII text format. These are the files Port_Channel_North_2013_Bathy_SingleBeam_ITRF00_xyz.txt, Port_Channel_South_2013_Bathy_SingleBeam_ITRF00_xyz.txt, Weeks_Bayou_2013_Bathy_SingleBeam_ITRF00_xyz.txt, and Shark_Island_Bayou_2013_Bathy_SingleBeam_ITRF00_xyz.txt that have been converted using VDatum v. 3.2. The x and y coordinates are reference to NAD83 (CORS96) UTM Zone 15 North, and the z values are referenced to NAVD88 orthometric height.
    Entity_and_Attribute_Detail_Citation: http://pubs.usgs.gov/ds/0835/
    Port_Channel_North_2013_Bathy_SingleBeam_ITRF00_raster2point_ellipsoid.shp, Port_Channel_South_2013_Bathy_SingleBeam_ITRF00_raster2point_ellipsoid.shp, Shark_Island_Bayou_2013_Bathy_SingleBeam_ITRF00_raster2point_ellipsoid.shp, Weeks_Bayou_2013_Bathy_SingleBeam_ITRF00_raster2point_ellipsoid.shp
    The DEMs converted from raster to point shapefiles using Esri's ArcGIS Conversion Tool raster to point (Source: Esri ArcGIS 10.1)
    FID
    Internal feature number (Source: Esri ArcGIS 10.1) Sequential unique whole numbers that are automatically generated
    SHAPE
    Point Feature Geometry (Source: Esri ArcGIS 10.1)
    Range of values
    Minimum:1
    Maximum:3564
    GRID_CODE
    Ellipsoid value at the center of every 10-m spaced grid node (Source: Esri ArcGIS 10.1)
    Range of values
    Minimum:-35.586
    Maximum:-27.932
    ITRF00_X
    The X or easting horizontal coordinate referenced to International Terrestrial Reference frame of 2000 (ITRF00) which is equal to WGS84 (G1150) (Source: CARIS HIPS and SIPS v. 8.0)
    Range of values
    Minimum:610403.451
    Maximum:616799.186
    Units:meters
    ITRF00_Y
    The Y or northing horizontal coordinate referenced to International Terrestrial Reference frame of 2000 (ITRF00) which is equal to WGS84 (G1150) (Source: CARIS HIPS and SIPS v. 8.0)
    Range of values
    Minimum:3292985.476
    Maximum:3304207.975
    Units:meters
    POINTID
    Internal feature number (Source: Esri ArcGIS 10.1)
    Range of values
    Minimum:1
    Maximum:6275
    Entity_and_Attribute_Overview:
    These shapefiles are the four DEM, raster files, west1_rm_10m, west2_rm_10m, east_rm_10m, and south_rm_10m, exported as point shapefiles using Esri's ArcGIS Conversion Tool raster to point. The x and y values are in ITRF00 and the z values are in ellipsoid height. Data range from -27.93 to -35.59 meters. Additionally each shapefile was saved as a Esri's ArcGIS layer file (.lyr) and as a (*.txt) with the same filename. These files are located within their respective folders located in the Data Downloads Folder.
    Entity_and_Attribute_Detail_Citation: http://pubs.usgs.gov/ds/0835/
    Port_Channel_North_2013_Bathy_SingleBeam_NAD83_NAVD88_GEOID12A _raster2point_orthometric.shp, Port_Channel_South_2013_Bathy_SingleBeam_NAD83_NAVD88_GEOID12A _raster2point_orthometric.shp, Shark_Island_Bayou_2013_Bathy_SingleBeam_NAD83_NAVD88_GEOID12A _raster2point_orthometric.shp, Weeks_Bayou_2013_Bathy_SingleBeam_NAD83_NAVD88_GEOID12A _raster2point_orthometric.shp
    The DEMs converted from raster to point shapefiles using Esri's ArcGIS Conversion Tool raster to point (Source: Esri ArcGIS 10.1)
    FID
    Internal feature number (Source: Esri ArcGIS 10.1) Sequential unique whole numbers that are automatically generated
    SHAPE
    Point Feature Geometry (Source: Esri ArcGIS 10.1) Point defining the feature
    POINTID
    Internal feature number (Source: Esri ArcGIS 10.1)
    Range of values
    Minimum:1
    Maximum:6275
    Resolution:1
    NAD83_X
    The X or easting horizontal coordinate referenced North American Datum 1983 with respect to Geoid 12A (Source: Esri ArcGIS 10.1)
    Range of values
    Minimum:610403.451
    Maximum:616799.186
    Units:meters
    NAD83_Y
    The Y or northing horizontal coordinate referenced North American Datum 1983 with respect to Geoid 12A (Source: Esri ArcGIS 10.1)
    Range of values
    Minimum:3292985.476
    Maximum:3304207.975
    Units:meters
    GRID_CODE
    Ellipsoid value at the center of every 10-m spaced grid node (Source: Esri ArcGIS 10.1)
    Range of values
    Minimum:-8.11
    Maximum:-0.64
    Units:meters
    Entity_and_Attribute_Overview:
    These shapefiles are the four DEM, raster files, west1_83_88rm, west2_83_88rm, east_83_88rm, and south_83_88, exported as point shapefiles using Esri's ArcGIS Conversion Tool raster to point. The x and y values are reference to NAD83 (CORS96) UTM Zone 15 North and the z values are referenced to NAVD88 orthometric height. Data range from -0.64 to -8.11 meters. Additionally each shapefile was saved as a Esri's ArcGIS layer file (.lyr) and as a (*.txt) with the same filename. These files are located within their respective folders located in the Data Downloads Folder.
    Entity_and_Attribute_Detail_Citation: http://pubs.usgs.gov/ds/0835/
    Entity_and_Attribute_Overview:
    The eight digital elevation models included in this archive are composed of single band, 32-bit floating- point continuous raster (Esri ArcGIS) data representing a gridded form of the elevation as derived from the single-beam bathymetry. The following four raster files, west1_rm_10m, west2_rm_10m, east_rm_10m, and south_rm_10m, contain elevations relative to WGS84 (G1150) and ellipsoid height in meters. Data range from -27.93 to -35.59 meters. Each DEM was saved as a Esri's ArcGIS layer file (.lyr) and placed within the respective GIS project folder. These files can be located within the Data Downloads Folder. The following are listed here for convenience: Port_Channel_North_2013_Bathy_SingleBeam_ITRF00_DEM.lyr = west1_rm_10m; Port_Channel_South_2013_Bathy_SingleBeam_ITRF00_DEM.lyr = west2_rm_10m; Weeks_Bayou_2013_Bathy_SingleBeam_ITRF00_DEM.lyr = east_rm_10m; and Shark_Island_Bayou_2013_Bathy_SingleBeam_ITRF00_DEM.lyr = south_rm_10m
    Entity_and_Attribute_Detail_Citation:
    The U.S. Geological Survey acquired all the data and created the various grids presented in this Data Series. To download the data please go to, http://pubs.usgs.gov/ds/0835/.
    Entity_and_Attribute_Overview:
    The eight digital elevation models included in this archive are composed of single band, 32-bit floating- point continuous raster (Esri ArcGIS) data representing a gridded form of the elevation as derived from the single-beam bathymetry. The following four DEM, raster files, west1_83_88rm, west2_83_88rm, east_83_88rm, and south_83_88, contain elevations relative to NAD83 and NAVD88 orthometric height in meters. Data range from -0.64 to -8.11 meters. Each DEM was saved as a Esri's ArcGIS layer file for convenience. Each DEM was saved as a Esri's ArcGIS layer file (.lyr) and placed within the respective GIS project folder. These files can be located within the Data Downloads Folder. The following are listed here for convenience: Port_Channel_North_2013_Bathy_SingleBeam_NAD83_NAVD88_GEOID12A_DEM.lyr = west1_83_88rm; Port_Channel_South_2013_Bathy_SingleBeam_NAD83_NAVD88_GEOID12A_DEM.lyr = west2_83_88rm; Weeks_Bayou_2013_Bathy_SingleBeam_NAD83_NAVD88_GEOID12A_DEM.lyr = east_83_88rm; and Shark_Island_Bayou_2013_Bathy_SingleBeam_NAD83_NAVD88_GEOID12A_DEM.lyr = south_83_88
    Entity_and_Attribute_Detail_Citation:
    The U.S. Geological Survey acquired all the data and created the various grids presented in this Data Series. To download the data please go to http://pubs.usgs.gov/ds/0835/.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Nancy T. DeWitt
    • Christopher D. Reich
    • Christopher G. Smith
    • B.J. Reynolds
  2. Who also contributed to the data set?
    Funding and (or) support for this study was provided by USGS second phase of the Northern Gulf of Mexico Program (NGOM2) USGS We would like to thank our USGS collaborators Cindy Thatcher from the USGS, Reston, Va., Dustin Kimbrow from the USGS Alabama Water Science Center in Montgomery, Ala., and Dean Gesch and Jeffrey Danielson from the USGS Earth Resources Observation and Science (EROS) Center in Sioux Falls, S. Dak., for their contribution to the survey. We would like to thank the Morton Salt Plant Weeks Island, La., location for allowing the USGS access to their property for GPS base station occupations. Great thanks and appreciation go to Darrell Anders at the USGS National Wetland Research Center Layfayette, La., for providing materials and repairs in the field on short notice. We also would like to acknowledge help with Web design, and general support from the following people: Jolene Gittens, Noreen Buster, Lance Thornton, and Kyle Kelso. Reviews of this document were also conducted by Kara Doran and Arnell Forde.
  3. To whom should users address questions about the data?
    Nancy T. DeWitt
    U.S. Geological Survey (USGS) - St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, Fla.,
    USA

    (727) 502-8000 x8058 (voice)
    ndewitt@usgs.gov

Why was the data set created?

Data presented here were collected as part of the Inland Bathymetry Mapping and Monitoring Project, which is funded by the U.S. Geological Survey's second phase of the Northern Gulf of Mexico Program (NGOM2). Single-beam bathymetry data were collected in January 2013 over ~1.5 square kilometer (km2). This report serves as an archive of the processed single-beam bathymetry data from USGS cruise 13CCT01. Data products herein include 10-m cell-size gridded and interpolated digital elevation models (DEM), and x,y,z data products. Additional files include trackline maps, error anlaysis maps, Field Activity Collection System (FACS) logs, and formal Federal Geographic Data Committee (FGDC) metadata.

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: 2013 (process 1 of 11)
    Acquisiton: The GPS base station was established on the pre-existing National Geodetic Survey (NGS) Benchmark Personal Identifier (PID) DL9074 located on the Morton Salt Plant property in New Iberia, La. The Ashtech Z-Xtreme GPS receiver recorded the 12-channel full-carrier-phase positioning signals (L1/L2) from the satellites via the Thales choke-ring antenna. This GPS instrument combination was duplicated on the survey vessel (rover). The GPS receivers recorded their positions concurrently at 1-second (s) recording intervals throughout the survey. Boat motion was recorded at 50-millisecond (ms) intervals using a Teledyne TSS Dynamic Motion Sensor 05 (TSS DMS-05). Bathymetric soundings were recorded at 50-ms intervals using a Knudsen 320 Bathy Profiler echosounder system. The single-beam data were acquired using the hydrographic software HYPACK version 10. All data strings from the instruments were streamed in real time through HYPACK. Sound velocity measurements and associated data (time, position) were collected separately using a Valeport mini sound velocity profiler(SVP) system. Person who carried out this activity:
    Nancy T. DeWitt
    U.S. Geological Survey (USGS) - St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, Fla.
    USA

    (727) 502-8000 x8058 (voice)
    ndewitt@usgs.gov
    Data sources produced in this process:
    • Raw bathymetry data files and raw navigation data files. Formats include binary, ephemeris, and text files.
    Date: 2013 (process 2 of 11)
    Data Processing of Differentially-Corrected Navigation: Each base station GPS file was processed to the roving survey vessel GPS file using GrafNav v. 8.10 (Novatel). During this process, steps were taken to ensure that the trajectory produced from the base to the rover was clean and produced fixed positions. From these processes a single differentially-corrected, precise position file at 1-s intervals was generated for each roving GPS session. Person who carried out this activity:
    Nancy T. DeWitt
    U.S. Geological Survey (USGS) - St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, Fla.
    USA

    (727) 502-8000 x8058 (voice)
    ndewitt@usgs.gov
    Data sources used in this process:
    • Raw navigation data files from the base and rover GPS receivers. Data formats include binary and ephemeris.
    Data sources produced in this process:
    • Post-processed differential navigation data for the boat (rover file), also considered the position file for boat. File format is text.
    Date: 2013 (process 3 of 11)
    Data Processing - Single-beam bathymetry: All data were processed using CARIS HIPS and SIPS v. 8.0. Using the data parser in CARIS, the GrafNav DGPS files were parsed together with the HYPACK RAW files and converted to HIPS format for editing. Next, auxiliary data (heave, roll, pitch, SVP) were scanned for any last outliers, a GPS tide computed, sound velocity profiles applied, and then merged. After merging the data, the soundings and crossings were re-evaluated in CARIS Subset editor then exported as one ASCII text file. Person who carried out this activity:
    Nancy T. DeWitt
    U.S. Geological Survey (USGS) - St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, Fla.
    USA

    (727) 502-8000 x8058 (voice)
    ndewitt@usgs.gov
    Data sources used in this process:
    • The combination of input files used were all in ASCII text format and consisted of: post-processed differential navigation; unprocessed HYPACK RAW bathymetric data; and sound velocity profile casts.
    Data sources produced in this process:
    • Post-processed bathymetry data file in ASCII text format: 13CCT01_SBB_03_xxx_ITRF00_West1.txt
    • Post-processed bathymetry data file in ASCII text format: 13CCT01_SBB_03_xxx_ITRF00_West2.txt
    • Post-processed bathymetry data file in ASCII text format: 13CCT01_SBB_03_xxx_ITRF00_South.txt
    • Post-processed bathymetry data file in ASCII text format: 13CCT01_SBB_03_xxx_ITRF00_East.txt
    Date: 2013 (process 4 of 11)
    Data Quality Assessment and Quality Control (QA/QC) and Digital Elevation Model (DEM) Creation: The processed bathymetry data were imported into Esri ArcMap version 10.1. A shapefile of the individual data points (x,y,z) was created and plotted in 1-m color coded intervals. An initial 10-m raster grid and a tinned model surface were created using the raster interpolation "natural neighbors" tool and the data management "TIN" tool, respectively; both are part of the ArcGIS 3D Analyst tool suite. The grid, tin surface, and x,y,z point- shapefile were used in conjunction to visually scan for any remaining discrepancies. Additionally, an Esri ArcMap add in program script was written in-house using Microsoft C/C++ v. 7.0 to evaluate the elevation differences at the intersection of crossing lines. Any areas identified as questionable were reviewed and if found to be unsatisfactory, the values were either deleted or statically adjusted. Once QA/QC was completed, the final 10-m raster DEM was created. A polygon was created using the extent of the survey tracklines and then converted into a raster mask using the ArcGIS "polygon to raster" conversion tool. The final grid was clipped to the raster mask using the ArcGIS Spatial Analyst "extract by raster mask" tool. The final product was a DEM, which can be found on the data downloads page (http://pubs.usgs.gov/ds/0835/Data_Downloads.html). Person who carried out this activity:
    Nancy T. DeWitt
    U.S. Geological Survey (USGS) - St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, Fla.
    USA

    (727) 502-8000 x8058 (voice)
    ndewitt@usgs.gov
    Data sources used in this process:
    • Post-processed bathymetry data file in ASCII text format. 13CCT01_SBB_03_xxx_ITRF00_West1_final.shp
    • Post-processed bathymetry data file in ASCII text format. 13CCT01_SBB_03_xxx_ITRF00_West2_final.shp
    • Post-processed bathymetry data file in ASCII text format. 13CCT01_SBB_03_xxx_ITRF00_East_final.shp
    • Post-processed bathymetry data file in ASCII text format. 13CCT01_SBB_03_xxx_ITRF00_South_final.shp
    Data sources produced in this process:
    • A 10-m raster digital elevation model (DEM) in WGS84 (G1150) UTM Zone 15N and ellipsoid height: west1_rm_10m
    • A 10-m raster digital elevation model (DEM) in WGS84 (G1150) UTM Zone 15N and ellipsoid height: west2_rm_10m
    • A 10-m raster digital elevation model (DEM) in WGS84 (G1150) UTM Zone 15N and ellipsoid height: east_rm_10m
    • A 10-m raster digital elevation model (DEM) in WGS84 (G1150) UTM Zone 15N and ellipsoid height: south_rm_10m
    Date: 2013 (process 5 of 11)
    A comparison of the DEM versus the sounding (x,y,z point data) was performed to evaluate how well the DEM represented the original sounding data quantitatively and spatially. This was done using the DEM surface and the original x,y,z point data shapefile and values were extracted using Esri ArcGIS version 10.0.2 Spatial Analyst extract values to points tool. This produced a set of elevation values from which the root mean square error (RMS) was calculated. For each area, the RMS values were plotted, color coded, and placed against the backdrop of the DEM. This provided a visual spatial representation of RMS error. Person who carried out this activity:
    Nancy T. DeWitt
    U.S. Geological Survey (USGS) - St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, Fla.
    USA

    (727) 502-8000 x8058 (voice)
    ndewitt@usgs.gov
    Data sources used in this process:
    • Post-processed bathymetry data file in ASCII text format. 13CCT01_SBB_03_xxx_ITRF00_West1_final.shp
    • Post-processed bathymetry data file in ASCII text format. 13CCT01_SBB_03_xxx_ITRF00_West2_final.shp
    • Post-processed bathymetry data file in ASCII text format. 13CCT01_SBB_03_xxx_ITRF00_East_final.shp
    • Post-processed bathymetry data file in ASCII text format. 13CCT01_SBB_03_xxx_ITRF00_South_final.shp
    Data sources produced in this process:
    • Port_Channel_North_2013_Bathy_SingleBeam_Error.shp
    • Port_Channel_South_2013_Bathy_SingleBeam_Error.shp
    • Weeks_Bayou_2013_Bathy_SingleBeam_Error.shp
    • Shark_Island_Bayou_2013_Bathy_SingleBeam_Error.shp
    Date: 2013 (process 6 of 11)
    These data were then converted horizontally and vertically into NAD83 (CORS96) UTM Zone 15 N and NAVD88 (orthometric height), respectively, using GEOID12A. The conversion was completed using the National Oceanic and Atmospheric Association (NOAA) VDatum software conversion tool v. 3.2 (reported vertical transformation error is 5.4 cm). Person who carried out this activity:
    Nancy T. DeWitt
    U.S. Geological Survey (USGS) - St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, Fla.
    USA

    (727) 502-8000 x8058 (voice)
    ndewitt@usgs.gov
    Data sources used in this process:
    • Post-processed bathymetry data file in ASCII text format. 13CCT01_SBB_03_xxx_ITRF00_West1_final.shp
    • Post-processed bathymetry data file in ASCII text format. 13CCT01_SBB_03_xxx_ITRF00_West2_final.shp
    • Post-processed bathymetry data file in ASCII text format. 13CCT01_SBB_03_xxx_ITRF00_East_final.shp
    • Post-processed bathymetry data file in ASCII text format. 13CCT01_SBB_03_xxx_ITRF00_South_final.shp
    Data sources produced in this process:
    • 13CCT01_SBB_Level_03_xxx_West1_NAD83_NAVD88_GEOID12A_xyz.txt
    • 13CCT01_SBB_Level_03_xxx_West2_NAD83_NAVD88_GEOID12A_xyz.txt
    • 13CCT01_SBB_Level_03_xxx_East_NAD83_NAVD88_GEOID12A_xyz.txt
    • 13CCT01_SBB_Level_03_xxx_South_NAD83_NAVD88_GEOID12A_xyz.txt
    Date: 2013 (process 7 of 11)
    Using the x,y,z data files output from Vdatum v. 3.2, a 10 m-raster DEM was created in Esri's ArcMap software. A polygon was created using the extent of the survey tracklines and then converted into a raster mask using the ArcGIS "polygon to raster" conversion tool. The final grid was clipped to the raster mask using the ArcGIS Spatial Analyst "extract by raster mask" tool. The final product was a digital elevation model referenced to North American Vertical Datum 1983 and North American Vertical Datum 1988. Data sources used in this process:
    • 13CCT01_SBB_03_xxx_West1_NAD83_NAVD88_GEOID12A.shp
    • 13CCT01_SBB_03_xxx_West2_NAD83_NAVD88_GEOID12A.shp
    • 13CCT01_SBB_03_xxx_East_NAD83_NAVD88_GEOID12A.shp
    • 13CCT01_SBB_03_xxx_South_NAD83_NAVD88_GEOID12A.shp
    Data sources produced in this process:
    • west1_83_88rm
    • west2_83_88rm
    • east_83_88rm
    • south_83_88rm
    Date: 2013 (process 8 of 11)
    DEM conversion from Raster to Point: The 10-m DEM was converted to a point shapefile using Esri's ArcMap "Raster to Point" conversion tool. Person who carried out this activity:
    Nancy T. DeWitt
    U.S. Geological Survey (USGS) - St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, Fla.
    USA

    (727) 502-8000 x8058 (voice)
    ndewitt@usgs.gov
    Data sources used in this process:
    • A 10-m raster digital elevation model (DEM) in WGS84 (G1150) UTM Zone 15N and ellipsoid height: west1_rm_10m
    • A 10-m raster digital elevation model (DEM) in WGS84 (G1150) UTM Zone 15N and ellipsoid height: west2_rm_10m
    • A 10-m raster digital elevation model (DEM) in WGS84 (G1150) UTM Zone 15N and ellipsoid height: east_rm_10m
    • A 10-m raster digital elevation model (DEM) in WGS84 (G1150) UTM Zone 15N and ellipsoid height: south_rm_10m
    • A 10-m raster digital elevation model (DEM) in NAD83 UTM Zone 15N and NAVD88 orthometric height: west1_83_88rm
    • A 10-m raster digital elevation model (DEM) in NAD83 UTM Zone 15N and NAVD88 orthometric height: west2_83_88rm
    • A 10-m raster digital elevation model (DEM) in NAD83 UTM Zone 15N and NAVD88 orthometric height: east_83_88rm
    • A 10-m raster digital elevation model (DEM) in NAD83 UTM Zone 15N and NAVD88 orthometric height: south_83_88rm
    Data sources produced in this process:
    • Port_Channel_North_2013_Bathy_SingleBeam_raster2point_ITRF00_ellipsoid.shp
    • Port_Channel_South_2013_Bathy_SingleBeam_raster2point_ITRF00_ellipsoid.shp
    • Weeks_Bayou_2013_Bathy_SingleBeam_ITRF00_raster2point_ITRF00_ellipsoid.shp
    • Shark_Island_Bayou_2013_Bathy_SingleBeam_raster2point_ITRF00_ellipsoid.shp
    • Port_Channel_North_2013_Bathy_SingleBeam_raster2point_NAD83_NAVD88_GEOID12A_orthometric.shp
    • Port_Channel_South_2013_Bathy_SingleBeam_raster2point_NAD83_NAVD88_GEOID12A_orthometric.shp
    • Weeks_Bayou_2013_Bathy_SingleBeam_raster2point_NAD83_NAVD88_GEOID12A_orthometric.shp
    • Shark_Island_Bayou_2013_Bathy_SingleBeam_raster2point_NAD83_NAVD88_GEOID12A_orthometric.shp
    Date: 2013 (process 9 of 11)
    Raster to Point Conversion: The point shapefiles were then exported to a text file. Person who carried out this activity:
    Nancy T. DeWitt
    U.S. Geological Survey (USGS) - St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, Fla.
    USA

    (727) 502-8000 x8058 (voice)
    ndewitt@usgs.gov
    Data sources used in this process:
    • Port_Channel_North_2013_Bathy_SingleBeam_raster2point_ITRF00_ellipsoid.shp
    • Port_Channel_South_2013_Bathy_SingleBeam_raster2point_ITRF00_ellipsoid.shp
    • Weeks_Bayou_2013_Bathy_SingleBeam_raster2point_ITRF00_ellipsoid.shp
    • Shark_Island_Bayou_2013_Bathy_SingleBeam_raster2point_ITRF00_ellipsoid.shp
    • Port_Channel_North_2013_Bathy_SingleBeam_raster2point_NAD83_NAVD88_GEOID12A_orthometric.shp
    • Port_Channel_South_2013_Bathy_SingleBeam_raster2point_NAD83_NAVD88_GEOID12A_orthometric.shp
    • Weeks_Bayou_2013_Bathy_SingleBeam_NAD83_raster2point_NAD83_NAVD88_GEOID12A_orthometric.shp
    • Shark_Island_Bayou_2013_Bathy_SingleBeam_raster2point_NAD83_NAVD88_GEOID12A_orthometric.shp
    Data sources produced in this process:
    • Port_Channel_North_2013_Bathy_SingleBeam_ITRF00_xyz.txt
    • Port_Channel_South_2013_Bathy_SingleBeam_ITRF00_xyz.txt
    • Weeks_Bayou_2013_Bathy_SingleBeam_ITRF00_xyz.txt
    • Shark_Island_Bayou_2013_Bathy_SingleBeam_ITRF00_xyz.txt
    • Port_Channel_North_2013_Bathy_SingleBeam_NAD83_NAVD88_GEOID12A_xyz.txt
    • Port_Channel_South_2013_Bathy_SingleBeam_NAD83_NAVD88_GEOID12A_xyz.txt
    • Weeks_Bayou_2013_Bathy_SingleBeam_NAD83_NAVD88_GEOID12A_xyz.txt
    • Shark_Island_Bayou_2013_Bathy_SingleBeam_NAD83_NAVD88_GEOID12A_xyz.txt
    Date: 2013 (process 10 of 11)
    Trackline Map Creation: The x,y,z data used to create the DEM were also used to create a polyline geometric shapefile representing the bathymetric tracklines. This was accomplished using Esri's XTools Pro feature conversion tool called "make polylines from points." Person who carried out this activity:
    Nancy T. DeWitt
    U.S. Geological Survey (USGS) - St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, Fla.
    USA

    (727) 502-8000 x8058 (voice)
    ndewitt@usgs.gov
    Data sources used in this process:
    • Post-processed bathymetry data file in ASCII text format. 13CCT01_SBB_03_xxx_ITRF00_West1_final.shp
    • Post-processed bathymetry data file in ASCII text format. 13CCT01_SBB_03_xxx_ITRF00_West2_final.shp
    • Post-processed bathymetry data file in ASCII text format. 13CCT01_SBB_03_xxx_ITRF00_East_final.shp
    • Post-processed bathymetry data file in ASCII text format. 13CCT01_SBB_03_xxx_ITRF00_South_final.shp
    Data sources produced in this process:
    • polyline shapefile: Port_Channel_North_2013_Bathy_SingleBeam_tracklines.shp
    • polyline shapefile: Port_Channel_South_2013_Bathy_SingleBeam_tracklines.shp
    • polyline shapefile: Weeks_Bayou_2013_Bathy_SingleBeam_tracklines.shp
    • polyline shapefile: Shark_Island_Bayou_2013_Bathy_SingleBeam_tracklines.shp
    Date: 13-Oct-2020 (process 11 of 11)
    Added keywords section with USGS persistent identifier as theme keyword. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    The accuracy of the data is determined during data collection. This dataset is from one research cruise and is therefore internally consistent. Methods are employed to maintain data collection consistency aboard the vessel. During mobilization, each piece of acquisition equipment is isolated to obtain internal and external offset measurements with respect to the survey platform. All the critical measurements are recorded manually and digitally entered into their respective programs. For single-beam bathymetry, offsets between the single-beam transducers and the Ashtech antenna reference point (ARP) were measured and accounted for in post-processing. Differential Geographic Positioning (DGPS) was obtained using post-processing software packages. DGPS is always implemented for navigational accuracy either during acquisition or as a post-processing step. Sound velocity profile casts (SVP) were taken for a comprehensive representation of the spatial, temporal, and varying water depths encountered during USGS cruise 13CCT01 and applied accordingly in the post-processing software program.
  2. How accurate are the geographic locations?
    All processed measurements are referenced to the base station coordinates. GPS base stations were erected within approximately 15 to 20 km of the survey area. The GPS antenna and receiver at the base station (base) were duplicated on the survey vessel (rover). The base receiver and the rover receiver record their positions concurrently at 1-second (s) recording intervals throughout the survey. All static base station GPS sessions were submitted for processing to the On-Line Positioning User Service (OPUS) maintained by the National Oceanic and Atmospheric Administration (NOAA) and the National Geodetic Survey (NGS). The base location results from OPUS were entered into a spreadsheet to compute one final positional coordinate and error analysis for that base location. The final positional coordinate (latitude, longitude, and ellipsoid height) is the weighted average of all GPS sessions. For each GPS session the weighted average was calculated using the OPUS result and the total session time in seconds; therefore, longer GPS occupation times held more value than shorter occupation times. The horizontal error for the GPS sessions was calculated as the absolute value of the final position minus the daily position. The final latitude and longitude positions were used as the base station horizontal coordinates in the processing software GrafNav version 8.3, by Novatel. For USGS cruise 13CCT01, the maximum horizontal error for MORT was 0.00008 to 0.00147 decimal seconds for latitude and 0.00012 to 0.00368 decimal seconds for longitude.
  3. How accurate are the heights or depths?
    All processed measurements are referenced to the base station coordinates and processed as described in the horizontal positional accuracey report. The vertical error for these GPS sessions was calculated as the absolute value of the final ellipsoid height value minus the daily ellipsoid height value. Any ellipsoid values greater than three standard deviations were excluded. This average weighted ellipsoid height was then used as the base station vertical coordinate in the processing software GrafNav version 8.3, by Novatel. During acquisition, ship motion was measured using a TSS DMS-05 heave, roll, and pitch sensor, which can measure within 0.05 m. The TSS data string was captured and recorded in the HYPACK RAW bathymetry data files. Using CARIS HIPS and SIPS v. 8.1, the differentially-corrected navigation files exported from GrafNav were parsed together by time with the HYPACK RAW files and then merged together, at which time the TSS measurements were used to geometrically correct the soundings at each differentially-corrected position. The average weighted value of the ellipsoid height (as reported from OPUS output files) is +/- 0.051 m for MORT.
  4. Where are the gaps in the data? What is missing?
    This data series provides complete processed bathymetry shapefiles, trackline maps, DEMs, and resultant x,y,z text files for each area surveyed during USGS cruise 13CCT01.
  5. How consistent are the relationships among the observations, including topology?
    This dataset was acquired on one research cruise during the course of 6 days in 2013. Refer to the FACS logs for respective vessel platform and survey information. This dataset was created to provide the post-processed bathymetry from USGS cruise 13CCT01. The DEMs presented here are 10-m grid node spacing.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints:
The U.S. Geological Survey requests that it be referenced as the originator of this dataset in any future products or research derived from these data.
Use_Constraints: These data are not to be used for navigation.
  1. Who distributes the data set? (Distributor 1 of 1)
    Nancy T. DeWitt
    U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    600 4th Street South
    St. Petersburg, Fla.
    USA

    (727) 502-8000 (voice)
    ndewitt@usgs.gov
  2. What's the catalog number I need to order this data set?
  3. What legal disclaimers am I supposed to read?
    This CD-ROM publication was prepared by an agency of the United States Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    These shapefiles were created for use with Esri ArcGIS software.

Who wrote the metadata?

Dates:
Last modified: 13-Oct-2020
Metadata author:
Nancy T. DeWitt
Geologist
600 4th Street South
Saint Petersburg, Fla.
USA

(727) 502-8000 (voice)
ndewitt@usgs.gov
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/spcmsc/13CCT01_SBB_metadata.faq.html>
Generated by mp version 2.9.50 on Tue Sep 21 18:18:29 2021