Enhanced sidescan-sonar TIFF images in geographic coordinates

Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: David C. Twichell
Publication_Date: 20000123
Title: Enhanced sidescan-sonar TIFF images in geographic coordinates
Publication_Information:
Publication_Place: Woods Hole, MA
Publisher: U.S. Geological Survey
Description:
Abstract:
Two 21-day field operations were conducted in 1997 and 1998 in the estuaries and on the inner continental shelf off the northern Oregon and southern Washington coast. These cruises aboard the R/V Corliss were run in order to generate reconnaissance maps of the seafloor geology and the shallow subsurface stratigraphy using sidescan-sonar and seismic-reflection mapping techniques. The 1998 cruise also collected sediment grab samples, bottom photographs, and video images to verify the sidescan-sonar imagery and to document the seafloor geology. The combination of these data with previously collected sediment sample data (Robert, 1974; Nittrouer, 1978; and Smith et. al., 1980) has been used to define the extent and lithology of shelf sediments associated with the Columbia River littoral cell. This work is one component of a larger project studying the erosion of the Washington Oregon coasts and is being coordinated by the U.S. Geological Survey and the Washington State Department of Ecology. The reasons for collecting these data are to provide a regional synthesis of the offshore geology for this project and to support a wide variety of management decisions and to provide a basis for further process-oriented investigations.
Purpose:
This is a collection of digital sidescan-sonar imagery in TIFF image format with corresponding TIFF world files for image registration. These images are stored in a geographic coordinate system with an image resolution of 2 m/pixel.
Supplemental_Information:
Roberts, R.W., 1974, Marine sedimentological data of the Washington continental shelf: University of Washington, Department of Oceanography Special Report 57, 129p.

Nittrouer, C.A., 1978, The process of detrital sediment accumulation in a continental shelf environment: an examination of the Washington shelf: PhD Thesis, University of Washington, Seattle, WA. 243p.

Smith, J.M., Messmer, L.W., Phipps, J.B., Samuelson, D.F., and Schermer, E.D., 1980, Grays Harbor and Chehalis River improvements to navigation environmental studies - Grays Harbor ocean disposal study: literature review and preliminary benthic sampling: U.S. Army Corps of Engineers Internal Report.

Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 19970827
Beginning_Time: 20040000Z
Ending_Date: 19970913
Ending_Time: 22200000Z
Currentness_Reference: 1998
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -124.500000
East_Bounding_Coordinate: -123.800000
North_Bounding_Coordinate: +47.350000
South_Bounding_Coordinate: +45.900000
Keywords:
Theme:
Theme_Keyword_Thesaurus: General
Theme_Keyword: Corliss
Theme_Keyword: CRLS98014
Theme_Keyword: image
Theme_Keyword: TIFF
Theme_Keyword: TIFF world file
Theme_Keyword: sidescan-sonar
Theme_Keyword: CRLS97007
Place:
Place_Keyword_Thesaurus: General
Place_Keyword: Pacific Ocean
Place_Keyword: Washington
Place_Keyword: Oregon
Place_Keyword: WA
Place_Keyword: OR
Place_Keyword: Inner shelf off Columbia River
Place_Keyword: Columbia River Littoral Cell
Access_Constraints: None
Use_Constraints:
The U.S. Geological Survey must be referenced as the originator of the dataset in any future products or research derived from these data.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: David C. Twichell
Contact_Organization: U.S. Geological Survey
Contact_Position: Oceanographer
Contact_Address:
Address_Type: mailing and physical address
Address:
U.S. Geological Survey
Woods Hole Field Center
384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: 508-548-8700
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: dtwichell@usgs.gov
Data_Set_Credit: Seafloor Mapping Group
Data_Quality_Information:
Logical_Consistency_Report:
All of the sidescan-sonar data were collected and processed in the same manner, with the following exception: In 1997, 14 files representing portions or all of 8 lines of data were collected and stored as 8-bit data rather than 16-bit data.  These lines are indicated in the 'tracks97' shapefile with the "acquired" attribute.
Completeness_Report:
All sidescan-sonar data collected on the two cruises, CRLS97007 and CRLS98014, are represented in these files.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
The sidescan-sonar data is merged with navigation collected with P-CODE GPS. No instrumentation was available to estimate the range to the sidescan-sonar towfish. However, most of the data were acquired in fairly shallow water, therefore the layback (wire out) was minimal.
Quantitative_Horizontal_Positional_Accuracy_Assessment:
Horizontal_Positional_Accuracy_Value: 10-20m
Horizontal_Positional_Accuracy_Explanation: P-CODE GPS has an accuracy greater than 10m
Lineage:
Process_Step:
Process_Description:
Sidescan-sonar data were collected using an EdgeTech sidescan-sonar system and logged to a Triton QMIPS data acquisition system. The EdgeTech system acquired data at a rate of 7.5 pulses/sec yielding a total swath width of 200m (100m range to each side of the sidescan-sonar towfish). The digital sidescan-sonar data were processed and mapped to provide proper geographic orientation of the data. Although the EdgeTech system is a dual-frequency system (100kHz and 500kHz), this particular study only processed and used the 100kHz data. The processing steps of the sidescan-sonar data included; subsampling the raw sidescan-sonar data using a median filtering routine to suppress speckle noise and reduce file size, and correcting for slant-range distortion, signal attenuation, and dropped sonar lines using the XSonar software package (Danforth et al., 1991). The sidescan-sonar data was then mapped into its proper geographic location at a resolution of 2 m/pixel using techniques summarized by Paskevich (1996).  The study area was broken into 4 areas (area1 being the northenmost, area4 the southernmost) so that each individual area would be a workable file size within the remote sensing software package PCI. Because this particular study consists of reconnaissance lines spaced approximately 5km apart, no mosaicking steps were applied.  Line crossings had no adjustments or shifts applied to the geographic position of the data. Some of the 1997 sidescan-sonar data was collected in an 8-bit format. These files were tone-matched to the 16-bit data. After tone matching, an enhancement was applied to all the sidescan sonar imagery such that the maximum pixel value is 254 with the minimum pixel value of 0. The imagery was then transferred to a background of 255. Rectangular segments of each of the 4 areas from each year of surveying were then exported as TIFF image files with associated world files for georeferencing. Due to the large size of the TIF images, they were compressed with the program GZIP such that the filenameconforms to the 8.3 format. An example of a filename is 'ar1_1.gz'.
Source_Used_Citation_Abbreviation: Danforth, W.W., O'Brien, T.F., and Schwab, W.C., 1991, USGS image processing system: near real-time mosaicking of high-resolution sidescan-sonar data:Sea Technology, Jan., 1991, p.54-59.
Source_Used_Citation_Abbreviation: Paskevich, V.F., 1996, MAPIT: An improved method for mapping digital sidescan sonar data using the Woods Hole Image Processing System (WHIPS) software: U.S. Geological Survey Open-File Report 96-281, 73p.
Process_Date: 19980800
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: VeeAnn A. Cross
Contact_Organization: U.S. Geological Survey
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: mailing and physical address
Address:
U.S. Geological Survery
Woods Hole Field Center
384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: 508-548-8700
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Pixel
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Geographic:
Latitude_Resolution: 0.000018
Longitude_Resolution: 0.000026
Geographic_Coordinate_Units: Decimal degrees
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.0
Denominator_of_Flattening_Ratio: 298.257222101
Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: Sidescan sonar imagery
Entity_Type_Definition: TIFF image
Entity_Type_Definition_Source: none
Attribute:
Attribute_Label: Filename
Attribute_Definition:
The image filename is a combination of the area from which it originated (ar1 to ar4), and a segement number. If the imagery is from 1998, a 98 is included in the filename. For example, 'ar1_1.gz' is the TIFF image in area1, segment 1, collected in 1997. The file 'ar1_198.gz' corresponds to the TIFF image in area1, segment 1, collected in 1998.
Attribute_Definition_Source: User defined
Attribute_Domain_Values:
Unrepresentable_Domain: character set
Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Nancy Soderberg
Contact_Organization: U.S. Geological Survey
Contact_Position: Data Librarian
Contact_Address:
Address_Type: mailing and physical address
Address:
U.S. Geological Survey
Woods Hole Field Center
384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: 508-548-8700
Contact_Facsimile_Telephone: 508-457-2313
Contact_Electronic_Mail_Address: nsoderberg@usgs.gov
Resource_Description: U.S. Geological Survey CD-ROM Open-File Report
Distribution_Liability:
This Compact Disc-Read Only Memory (CD-ROM) publication was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data published on this CD-ROM have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials and/or the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of this data, software, or related materials.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: TIFF
File_Decompression_Technique: GZIP file compression
Digital_Transfer_Option:
Offline_Option:
Offline_Media: CD-ROM
Recording_Capacity:
Recording_Density: 650
Recording_Density_Units: MBytes
Recording_Format: ISO 9600 with Rock Ridge extensions
Compatibility_Information: UNIX, DOS, MAC
Fees: none at this time
Technical_Prerequisites:
The user must have a program capable of reading and processing 'geotif' images.
Metadata_Reference_Information:
Metadata_Date: 20000104
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: VeeAnn A. Cross
Contact_Organization: U.S. Geological Survey
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: mailing and physical address
Address:
U.S. Geological Survey
Woods Hole Field Center
384 Woods Hole Rd
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: 508-548-8700
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: 19940608

Generated by mp on Tue Jan 25 16:10:03 2000