4-m resolution bathymetric grid of Tomales Bay, California (TOMALESG)

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Metadata:

Identification_Information:

Citation:
Citation_Information:
Originator: Roberto J. Anima
Originator: John L. Chin
Originator: David P. Finlayson
Originator: Mary L. McGann
Originator: Florence L. Wong
Publication_Date: 2007
Title:
4-m resolution bathymetric grid of Tomales Bay, California (TOMALESG)
Edition: Version 1.0, September 19, 2007
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: USGS OFR 2007-xxxx
Publication_Information:
Publication_Place: Menlo Park, California
Publisher: U.S. Geological Survey
Online_Linkage: <URL:https://pubs.usgs.gov/of/2008/1237/>

Description:

Abstract:
The Tomales Bay bathymetry Digital Elevation Model (DEM) is composed of data from three bathymetric surveys collected between November 2004 and August 2006 (USGS activities F-1-04-TB, F-2-05-TB, B-1-06-TB). During the 2004 and 2005 surveys, the northern and central bay bathymetry was collected using an interferometric sidescan system. In 2006, the shoal tidelands in the southern portion of the bay were surveyed using a single-beam echo sounder. The final data set described in this report is a composite of these three surveys.

This metadata record describes the Tomales Bay grid exported as

1. ESRI ASCII grid format (includes nodata -9999 values) 

 ncols         3172
 nrows         3959
 xllcorner     501413.013329
 yllcorner     4216501.279255
 cellsize      4
 NODATA_value  -9999
 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999
 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999
 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999
 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999
 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999
 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999
 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999 -9999
 -9999 -9999 -5.298165 -4.233628 -9999 -9999 -9999
 -9999 -9999 -9999 -9999 -9999 -
2. x-y (decimal degrees) and z (elevations in meters) data (nodata excluded). 

 -122.98086,38.23902,-5.298
 -122.98082,38.23902,-4.234
 -122.98090,38.23898,-5.162
 -122.98086,38.23898,-5.997
Purpose:

These data are intended for science researchers, students, policy makers, and the general public. The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information.

Supplemental_Information:

Additional information about the field activities from which this data set was derived are available online at 

<http://walrus.wr.usgs.gov/infobank/f/f104tb/html/f-1-04-tb.meta.html>
<http://walrus.wr.usgs.gov/infobank/f/f205tb/html/f-2-05-tb.meta.html>
<http://walrus.wr.usgs.gov/infobank/b/b106tb/html/b-1-06-tb.meta.html>
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 ArcInfo format, this metadata file may include some ArcInfo-specific terminology.

Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2006
Currentness_Reference: Ground Condition

Status:
Progress: Complete
Maintenance_and_Update_Frequency: None Planned

Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -122.98388487
East_Bounding_Coordinate: -122.83886718
North_Bounding_Coordinate: 38.23903649
South_Bounding_Coordinate: 38.09620335

Keywords:
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: coastal geology
Theme_Keyword: bathymetry
Theme_Keyword: sidescan
Theme_Keyword: interferometric sidescan
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: environment
Theme_Keyword: geoscientificInformation
Theme_Keyword: oceans
Place:
Place_Keyword_Thesaurus: Geographic Names Information System
Place_Keyword: Tomales Bay, California
Place_Keyword: Inverness Ridge, California
Place_Keyword: San Andreas Fault, California
Place_Keyword: Avalis Beach, California
Place_Keyword: Lawsens Landing, California
Place_Keyword: Pelican Point, California
Place_Keyword: Blakes Landing, California
Place_Keyword: Marconi, California
Place_Keyword: Hearts Desire Beach, California
Place_Keyword: Millerton Point, California
Place_Keyword: Inverness, California
Place_Keyword: Lagunitas Creek, California
Place_Keyword: Toms Point, California
Place_Keyword: White Gulch, California
Place_Keyword: Tomales Beach, California
Place_Keyword: Marshall Beach, California
Place_Keyword: Lairds Landing, California
Place_Keyword: Cypress Grove, California
Place_Keyword: Reynolds, California
Place_Keyword: California
Place_Keyword: USA
Place:
Place_Keyword_Thesaurus: GEOnet Names Server
Place_Keyword: north Pacific Ocean

Access_Constraints: None

Use_Constraints: These data are not to be used for navigation.

Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Florence L. Wong
Contact_Organization:
United States Geological Survey (USGS) Coastal and Marine Geology (CMG)
Contact_Position: Geologist, GIS Coordinator
Contact_Address:
Address_Type: mailing and physical address
Address: USGS, MailStop 999, 345 Middlefield Road
City: Menlo Park
State_or_Province: CA
Postal_Code: 94025-3561
Country: USA
Contact_Voice_Telephone: (650) 329-5327
Contact_Facsimile_Telephone: (650) 329-5190
Contact_Electronic_Mail_Address: fwong@usgs.gov

Native_Data_Set_Environment:
SunOS, 5.8, sun4u UNIX ArcInfo version 9.1

Browse_Graphic:
Browse_Graphic_File_Name: <https://pubs.usgs.gov/of/2008/1237/images/tomalesg.jpg>
Browse_Graphic_File_Description: preview image of report
Browse_Graphic_File_Type: gif or jpg

Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
The advertised accuracy of the SWATHplus system in shallow waters is better than IHO S44 Special Order, but a total propagation error model has not been developed for the USGS system used in these surveys so the true error in both position and elevation is unknown. Furthermore, no operational tide measurements were available for the survey so there is likely to be a spatially and temporally variable vertical error due to differences between the predicted tides and the water levels actually experienced during the survey. Finally, a comparison of grid elevations having overlapping coverage between the 2004 and 2005 surveys revealed a 1.44 m vertical offset (median of all overlapping cells). This error may be due to a mis-configuration of the F180 unit, but the exact cause of the error is unknown. In the final DEM, a static offset of +1.44 m was added to the 2004 data to minimize the vertical offset between the 2004 and 2005 data. No additional vertical error analysis has been performed on these data.

Logical_Consistency_Report: Not applicable for raster data.

Completeness_Report: See Attribute_Accuracy_Report.

Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report: See Attribute_Accuracy_Report.

Lineage:
Process_Step:
Process_Description:
Swath bathymetry. Swath bathymetry for the northern and central portions of Tamales Bay (cruise F-1-04-TB and F-2-05-TB) were collected using a pole-mounted, SEA Inc., 234 kHz, SWATHplus interferometric sidescan sonar system. Attitude compensation and vessel positioning were provided by a CodaOctopus F180 attitude and positioning system. Sound velocity profile measurements were collected with an Applied Micro Systems, SvPlus 3472.

The horizontal datum of the surveys was established by differential GPS using the WGS84 ellipsoid. The vertical datum of the surveys was based on Mean Lower Low Water (MLLW) predictions for Marshall, Tomales Bay, using the software Tides and Currents by Nobeltec.

Raw bathymetry and amplitude data were collected using the Swath Processor software provided with the sonar system and gridded at 1 m resolution using the accompanying Grid Processor software package. These raster data were then exported to Fledermaus, edited and smoothed in that package and finally exported to ESRI ASCII Grid format using USGS in-house software.

Process_Date: 2006

Process_Step:
Process_Description:
Single-Beam Bathymetry. Single-beam echo sounder data were collected over the shallow tidelands of southern Tomales Bay during August 2006 (cruise B-1-06-TB). A pole-mounted ESE50 Echo sounder with a co-located Real-time kinematic (RTK) GPS receiver system provided real-time vertical and horizontal positioning of the sonar transducer during operations. These data were reduced to positional soundings on the sea floor using HYPACK (version 6.2) with a 30-second averaging period (to remove heave), gridded into a 10-m resolution DEM using Surfer version 8.0, and exported to ESRI ASCII Grid format using USGS in-house software.

The horizontal and vertical datum of the survey was established by the RTK GPS system as WGS84 and NAVD88, respectively. The error ellipse on the location of the GPS receivers is typically < 5 cm and this propagates through to the sea floor with RMS errors on sea bed elevation of < 10 cm.

Process_Date: 2006

Process_Step:
Process_Description:
4 m composite bathymetry. Each of the three surveys was resampled to a 4 m cell spacing using the Spline Smooth tool of Surfer 8. The swath bathymetry was converted from MLLW to NAVD88 vertical datum using VDatum (NOAA Office of the Coast Survey and National Geodetic Survey), and then the three surveys were blended together in ArcGIS using the MOSAIC TO NEW RASTER tool with the blend option. The final data set was trimmed to the convex hull of the survey data area.
Process_Date: 2006

Process_Step:
Process_Description:
First draft of metadata created by florence using FGDCMETA.AML ver. 1.35 08/02/2000 on ArcInfo data set /we6/florence/cordell/tomales/covs/tomalesg
Process_Date: 20070919

Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Grid Cell
Row_Count: 3959
Column_Count: 3172

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: -123.0
Latitude_of_Projection_Origin: 0.0
False_Easting: 500000
False_Northing: 0
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 4.0
Ordinate_Resolution: 4.0
Planar_Distance_Units: Meters
Geodetic_Model:
Horizontal_Datum_Name: WGS84
Ellipsoid_Name: WGS84
Semi-major_Axis: 6378206.4
Denominator_of_Flattening_Ratio: 294.98

Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview: 


TOMALESG.STA:

COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
    1  MIN                    8    15     F      3
    9  MAX                    8    15     F      3
   17  MEAN                   8    15     F      3
   25  STDV                   8    15     F      3

 MIN             MAX            MEAN            STDV
 -19.150           0.668          -4.379           2.452
Entity_and_Attribute_Detail_Citation: none

Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
United States Geological Survey (USGS) Coastal and Marine Geology (CMG)
Contact_Person: Florence L. Wong
Contact_Position: Geologist, GIS Coordinator
Contact_Address:
Address_Type: mailing and physical address
Address: USGS, MailStop 999, 345 Middlefield Road
City: Menlo Park
State_or_Province: CA
Postal_Code: 94025-3561
Country: USA
Contact_Voice_Telephone: (650) 329-5327
Contact_Facsimile_Telephone: (650) 329-5190
Contact_Electronic_Mail_Address: fwong@usgs.gov
Resource_Description: USGS OFR 2007-xxx

Distribution_Liability:
Please recognize the U.S. Geological Survey (USGS) as the source of this information.

Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data.

The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials.

Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: Compressed file including Arcinfo grid and metadata.
Format_Version_Number: 9.2
Format_Specification: Arcinfo ASCII grid
File_Decompression_Technique: windows winzip or unix gunzip
Transfer_Size: 5 MB
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: <https://pubs.usgs.gov/of/2008/1237/>
Fees: none

Metadata_Reference_Information:
Metadata_Date: 20070919
Metadata_Review_Date: 200710
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
United States Geological Survey (USGS) Coastal and Marine Geology (CMG)
Contact_Person: Florence L. Wong
Contact_Position: Geologist, GIS Coordinator
Contact_Address:
Address_Type: mailing and physical address
Address: USGS, MailStop 999, 345 Middlefield Road
City: Menlo Park
State_or_Province: CA
Postal_Code: 94025-3561
Country: USA
Contact_Voice_Telephone: (650) 329-5327
Contact_Facsimile_Telephone: (650) 329-5190
Contact_Electronic_Mail_Address: fwong@usgs.gov
Metadata_Standard_Name:
FGDC Content Standards for Digital Geospatial Metadata ("CSDGM version 2")
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Access_Constraints: none
Metadata_Use_Constraints: none
Generated by mp version 2.8.11 on Wed Oct 24 13:25:02 2007