Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 2003 Title: Geophysical Surveys of Bear Lake, Utah-Idaho, September, 2002 - Sidescan-sonar Mosaic Geospatial_Data_Presentation_Form: raster data Description: Abstract: Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped depression tilted toward the main fault on the east side of the lake. The U.S. Geological Survey, in cooperation with researchers from several universities, has been studying the sediments of Bear Lake since 1996. The general purpose of this effort is to reconstruct past limnological conditions and regional climate on a range of timescales, from hundreds of years to hundreds of thousands of years. This research relates to a variety of human concerns, including water usage in the Bear River basin. Past work has included several coring operations, a seismic-reflection survey, sediment-trap deployments, a barge-mounted drilling operation with the GLAD800 drill rig, and a variety of other studies. The objectives of the September, 2002 operations, preliminarily reported here, were (1) to compile a detailed bathymetric map of the lake using swath-mapping techniques, in order to provide baseline data for a variety of applications and studies, and (2) to complete a sidescan-sonar survey of the lake, providing a nearly complete acoustic image of the lake floor. Limited amounts of subbottom acoustic-reflection data (CHIRP) were also collected, along with samples of lake-floor sediments representative of different kinds of backscatter patterns. These surveys followed an earlier subbottom acoustic-reflection survey (1997), using boomer and 3.5 kHz systems (S. M. Colman, unpublished data). Purpose: These data represent the first sidescan-sonar survey of Bear Lake, Utah-Idaho. This survey covered 100 percent of the lake floor below 5 meter water depth. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20020904 Ending_Date: 20020916 Currentness_Reference: Publication Date Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -111.5 East_Bounding_Coordinate: -111.17 North_Bounding_Coordinate: 42.2 South_Bounding_Coordinate: 41.08 Keywords: Theme: Theme_Keyword_Thesaurus: General Theme_Keyword: sonar Theme_Keyword: Sidescan-sonar Theme_Keyword: backscatter Theme_Keyword: geophysics Theme_Keyword: U.S. Geological Survey Theme_Keyword: USGS Theme_Keyword: Coastal and Marine Geology Program Theme_Keyword: CMGP Theme_Keyword: Woods Hole Field Center Place: Place_Keyword_Thesaurus: None Place_Keyword: Bear Lake Place_Keyword: Utah Place_Keyword: Idaho Place_Keyword: Western Lakes Place_Keyword: North America Place_Keyword: United States Access_Constraints: None. Use_Constraints: The USGS asks to be referenced in any use of these data. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Jane F. Denny Contact_Organization: U.S. Geological Survey Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical address Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543 Country: USA Contact_Voice_Telephone: 508-457-2311 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: jdenny@usgs.gov Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: These data are internally consistent and accurate. Logical_Consistency_Report: These data are logically consistent; they were acquired with an Edgetech DF-1000 sidescan-sonar system, and processed following an identical procedure. Completeness_Report: These data are complete. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: WAAS is assumed to be accurate within 1-2 meters. Standard GPS is assumed accurate within 5-10 meters. All data were recorded using the WAAS (Wide Area Augmentation System) navigation. All WAAS data are referenced to WGS84 datum. Slant-range distance was assumed to be negligable; the tow-fish was flown at a static height adjacent to the boat. Lineage: Process_Step: Process_Description: The sidescan-sonar data were acquired with a 100 kHz Edgetech sidescan-sonar system. All sidescan-sonar data were logged digitally at a sample rate resulting in a 0.18-m pixel size in the across-track direction and approximately 0.14-m in the along-track direction following the methodology outlined in Danforth and others (1991). A median filtering routine (Malinverno and others, 1990) was applied to the sidescan-sonar data to remove speckle noise, resulting in a 0.73-m pixel size. The data for each survey were further processed and digitally mosaicked using PCI Geomatica Software and procedures described in Danforth and others (1991), Danforth (1997), and Paskevich (1992) resulting in an enhanced, geographically correct, sidescan-sonar mosaic with 1 meter/pixel resolution. The composite mosaic was exported as a TIFF image, with an associated ESRI world file. Source_Used_Citation_Abbreviation: Danforth, W.W., 1997, Xsonar/ShowImage: A complete system for rapid sidescan-sonar processing and display: U.S. Geological Survey Open File Report 97-686, 77 p. Source_Used_Citation_Abbreviation: Danforth, W.W., O'Brien, T.F., and Schwab, W.C., 1991, USGS Image processing system: near real-time mosaicking ofhigh-resolution sidescan-sonar data Sea Technology, Vol 1, p.54-59. Source_Used_Citation_Abbreviation: Malinverno, A., Edwards, M, and Ryan, W.B.F, 1990, Processing of SeaMARC swath sonar data: IEEE, Journal of Coean Enginneering, v.15, p. 14-23. Source_Used_Citation_Abbreviation: Paskevich, V., 1992, Digital mapping of sidescan-sonar data with the Woods Hole Image Processing System software: U.S. Geological Survey Open-File Report 92-536, 87.p Process_Date: 20030916 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Jane F. Denny Contact_Organization: U.S. Geological Survey Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical address Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543 Country: USA Contact_Voice_Telephone: 508-457-2311 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: jdenny@usgs.gov Process_Step: Process_Description: The TIFF image (sonar.tif) was compressed using LizardTech, MrSID GeoSpatial Encoder 1.3.1. This software compresses the image at a specified ratio; 20:1 by default. An associated .sdw (ESRI world file) file is written with the compressed .sid file. In order to view these data within ArcView, the MrSID Image Support extension must be loaded. Once, the extension is loaded, the .sid image file can be loaded into ArcView as an Image. Process_Date: 20030916 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Jane F. Denny Contact_Organization: U.S. Geological Survey Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical address Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543 Country: USA Contact_Voice_Telephone: 508-457-2311 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: jdenny@usgs.gov Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator Universal_Transverse_Mercator: UTM_Zone_Number: 12 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.9996 Longitude_of_Central_Meridian: -111.000000 Latitude_of_Projection_Origin: +00.000000 False_Easting: 500000 False_Northing: 0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 500000 Ordinate_Resolution: 400000 Planar_Distance_Units: Meters Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: Tiff Image Entity_Type_Definition: Sidescan-sonar image stored in TIFF format Entity_Type_Definition_Source: ESRI Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: Jane F. Denny Contact_Organization: U.S. Geological Survey Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical address Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543 Country: USA Contact_Voice_Telephone: 508-457-2311 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: jdenny@usgs.gov Resource_Description: bear.sid Distribution_Liability: Altough this data set and its lineage have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and/or it's related materials. The act of distribution shall not constitute any such warranty, and no resposibility is assumed by the USGS in the use of these data or related items. Users must assume resposibility for the proper use of this data. This data should not be used at resolutions for which it is not intended. This data has no been reviewed for conformity with U.S. Geological Survey editorial standards, or the North American Strigraphic code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the US Government. Metadata_Reference_Information: Metadata_Date: 20020119 Metadata_Review_Date: 2002 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Jane F. Denny Contact_Organization: U.S. Geological Survey Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical address Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543 Country: USA Contact_Voice_Telephone: 508-457-2311 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: jdenny@usgs.gov Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Access_Constraints: None Metadata_Use_Constraints: None