Identification_Information: Citation: Citation_Information: Originator: A.J. Stevenson Originator: Florence L. Wong Publication_Date: 2002 Title: Bathymetric xyz data for Glacier Bay at 5-meter intervals. Edition: Version 1.0, December 10, 2002 Geospatial_Data_Presentation_Form: map Series_Information: Series_Name: USGS Open-File Report Issue_Identification: 02-391 Publication_Information: Publication_Place: Menlo Park, California Publisher: U.S. Geological Survey Online_Linkage: Description: Abstract: This data set consists of 5-m gridded bathymetric data for Glacier Bay, Alaska, in xyz form. The data were interpolated across "nodata" gaps that were no more than 30 meters wide. Data were collected during May 29 - June 6, 2001, by contract with Thales Geosolutions (http://www.thales-geopacific.com/) aboard the R/V Davidson as part of a cooperative survey conducted by the U.S. National Park Service and the U.S. Geological Survey (Biological Resources and Coastal and Marine Geology). The instrument was a Reson 8111 multibeam echosounder (http://reson.com/sb8111.htm). The raw data were reduced by Thales. 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/d/d101gb/html/d-1-01-gb.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. Specifications for the Reson SeaBat 8111 Multibeam Echosounder (http://www.reson.com/sb8111.htm) > Operating frequency: 100 kHz > Number of beams: 101 > Beamwidth across track: 1.5 degrees > Beamwidth along track: 1.5 degrees > Center-to-center beam separation: 1.5 degrees > Pulse length: Variable, operator selectable > Depth range: 3 - 1000 meters > Transducer depth rating: 100 meters > Max. update rate: 35 swaths per second > Max. vessel Speed: 20 knots > Stabilization: Pitch stabilization within +/- 10 degrees > Projector beam control: External pitch sensor > Hydrophone size (Dia./arc/length): 640mm, 220 degrees, 200mm > Processor Dimensions (HWD): 177 x 483 x 434 mm > Tranceiver Dimensions (HWD): 267 x 450 x 427 mm > Weight: (with 15m cable): > Hydrophone Dry: 42 kg Wet: 36 kg > Projector Dry: 30 kg Wet: 23 kg > Transceiver weight: 13.6 kg > Processor weight: 20 kg 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: 2002 Currentness_Reference: Ground Condition Status: Progress: In work Maintenance_and_Update_Frequency: As Needed. Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -136.40276708 East_Bounding_Coordinate: -135.91167668 North_Bounding_Coordinate: 58.75728909 South_Bounding_Coordinate: 58.35942274 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: bathymetry Theme_Keyword: multibeam Theme_Keyword: echosounder Place: Place_Keyword_Thesaurus: None Place_Keyword: Glacier Bay Place_Keyword: Alaska Access_Constraints: None. Use_Constraints: Data not to be used for navigational purposes. 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, 5.7, sun4u UNIX ArcInfo version 8.0.2 Browse_Graphic: Browse_Graphic_File_Name: glacier.gif Browse_Graphic_File_Description: index map of Glacier Bay multibeam bathymetry data Browse_Graphic_File_Type: GIF Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Not applicable. Logical_Consistency_Report: Not applicable for raster data. Completeness_Report: Data values are missing in and around shallow or emergent features (islands) and where adjoining trackline coverage was not overlapping. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Navigation was multiple DGPS [differential global positioning systems] coupled up with 2 very precise DR [dead-reckoning] 3-axis accelerometers, all integrated in WinFrog (proprietary software from Thales Geosolutions http://www.thales-geopacific.com/offshore/index.html). The best functional test we did was crossties, which suggested that average navigational errors were on the order of 1 meter, with (rare) maximum errors being about 3 meters. (A.J. Stevenson, written communtication, October 2001) Lineage: Process_Step: Process_Description: Raw data processed by contractor Thales Geosolutions and provided as 10-m and 5-m xyz values in UTM 8 coordinate system. Process_Date: 2001 Process_Step: Process_Description: F.L. Wong converted xyz to ArcInfo grids. Data were processed in 50,000-point blocks. Each block of points was used to GENERATE a point coverage. The point coverage for each block was merged with adjoining blocks, the grid IDW function was applied with default options, and the resulting grid clipped to the boundary of the block. All the interpolated grids were merged into a continuous grid GLACIER05MIG that was corrected by a mask that omitted data in holes that exceed 30 meters in width. The masking grid was constructed as follows: a unit grid (data cells = 1, all others = nodata) was copied from a 5-m uninterpolated grid. The unit grid was converted to a polygon coverage from which polygons with areas of less than 1000 square meters were removed in bulk. The remaining interior polygons were inspected in Arcedit and removed if the width were about 30 meters or less. This polygon coverage was converted back to a grid to be applied as a mask to the merged grids described in the previous paragraph. Process_Date: 2001 Process_Step: Process_Description: UTM grid was converted to a point coverage by Arc tool GRIDPOINT. Point coverage was projected to decimal degrees, and longitude, latitude, and depth values extracted. Process_Date: 2002 Process_Step: Process_Description: First draft of metadata created by curator using FGDCMETA.AML ver. 1.35 08/02/2000 on ArcInfo data set /arcdata/bathymetry/glacier05mg Process_Date: 20011018 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Point Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Point Point_and_Vector_Object_Count: 16906963 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.00004910904 Longitude_Resolution: 0.00004910904 Geographic_Coordinate_Units: Decimal Degrees Geodetic_Model: Horizontal_Datum_Name: nad83 Ellipsoid_Name: GRS1980 Semi-major_Axis: 6378206.4 Denominator_of_Flattening_Ratio: 294.98 Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: Each record consists of three fields: longitude, latitude, and depth in meters. Example of records: > -136.26066,58.75442,-137.124 > -136.26074,58.75438,-139.409 > -136.26066,58.75438,-137.124 > -136.26057,58.75438,-136.976 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 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. Metadata_Reference_Information: Metadata_Date: 20021210 Metadata_Review_Date: 2002 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