U.S. Geological Survey 2006 remote-sensing image Woods Hole Science Center, Woods Hole, MA U.S. Geological Survey, Coastal and Marine Geology Program http://pubs.usgs.gov/of/2005/1048/data/backscatter/mosaic/mercator/capesouthmos_mer4m.zip http://pubs.usgs.gov/of/2005/1048/data/backscatter/mosaic/mercator/capesouthmos_mer4m.tif http://pubs.usgs.gov/of/2005/1048/htmldocs/data_catalog.htm L.J. Poppe V.F. Paskevich B. Butman P.C. Valentine W.W. Danforth D.S. Foster D.S. Blackwood 2006 1.0 Open-File Report 2005-1048 Woods Hole Science Center, Woods Hole, MA U.S. Geological Survey, Coastal and Marine Geology Program http://pubs.usgs.gov/of/2005/1048/ capesouthmos_mer4m.tifhttp://pubs.usgs.gov/of/2005/1048/data/backscatter/mosaic/mercator/1.0Open-File Report2005-1048 This data set includes backscatter intensity of the sea floor offshore of eastern Cape Cod, Massachusetts. The data were collected with a multibeam sea floor mapping system during USGS survey 98015, conducted November 9 - 25, 1998. The surveys were conducted using a Simrad EM 1000 multibeam echosounder mounted aboard the Canadian Coast Guard vessel Frederick G. Creed. This multibeam system utilizes 60 electronically aimed receive beams spaced at intervals of 2.5 degrees that insonify a strip of sea floor up to 7.5 times the water depth (swath width of 100 to 200 m within the survey area). The horizontal resolution of the beam on the sea floor is approximately 10% of the water depth. Vertical resolution is approximately 1 percent of the water depth. With backscatter intensity, the intensity of the acoustic return from the sea floor from the multibeam system, is a function of the properties of the surficial sediments and of the bottom roughness. Generally, a strong return (light gray tones) is associated with rock or coarse-grained sediment, and a weak return (dark gray tones) with fine-grained sediments. However, the micro-topography, such as ripples, burrows, and benthic populations also affect the reflectivity of the sea floor. Direct observations, using bottom photography or video, and surface samples, are needed to verify interpretations of the backscatter intensity data. The backscatter data have a weak striping that runs parallel to the ship's track. Some of the striping is the result of poor data return at nadir that appears as evenly-spaced thin speckled lines. Some striping is also due to critical angle effects, where the intensity of return varies as a function of the angle of incidence of the incoming sound on the seafloor (Hughes-Clark and others, 1997). To release a digital map (GeoTIFF image) derived from multibeam observations that shows sea floor backscatter intensity (a measure of sea floor texture and roughness) at a spatial resolution of 4 m/pixel. en 19981109 19981125 ground condition Complete None planned -70.000000 -69.828333 41.970000 41.616667 26381.35000040681.3500003798007.7100003837339.710000 General U.S. Geological Survey USGS Woods Hole Science Center WHSC Coastal and Marine Geology Program CMGP Frederick G. Creed Field Activity Number 98015 Sea Floor Mapping Multibeam Echo Sounder Backscatter Intensity multibeam backscatter mosaic GeoTIFF Image greyscale image gray scale image Geographic Information System Sea Floor Geology Surficial Geology GeoTIFF Image Multibeam Simrad EM1000 ISO 19115 Topic Category oceans and estuaries imageryBaseMapsEarthCover geoscientificInformation General Cape Cod Massachusetts Cape Cod National Seashore Park U.S. East Coast United States North America Atlantic Ocean None Public domain data are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS) as the source of this information. U.S. Geological Survey Lawrence J. Poppe Geologist mailing and physical address

384 Woods Hole Road

Woods Hole MA 02543-1598 USA (508) 548-8700 x2314 (508) 457-2310 lpoppe@usgs.gov http://pubs.usgs.gov/of/2005/1048/data/backscatter/mosaic/mercator/capesouthmos_mer4m-thumb.gif Thumbnail image showing the extent and coverage of the data layer. GIF http://pubs.usgs.gov/of/2005/1048/data/backscatter/mosaic/mercator/capesouthmos_mer4m.gif Image map showing the extent and coverage of the data layer. GIF Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.722 L.J. Poppe D.S. Foster W.W. Danforth 2006 1.0 Geo-Marine Letters v. 26 Germany Springer Raster Dataset All collected data were processed and used to produce this dataset. Navigation was by differential GPS. DVD-ROM 19980925 19981109 ground condition 98015_multibeam_data The original multibeam backscatter data acquired with a Simrad EM 1000 echosounder during USGS cruise 98015 aboard the Canadian Coast Guard vessel Frederick G. Creed. (1) Data and acquisition processing at sea: After the echo sounder data were logged onto the hard disk of the Sun workstation, a suite of processing software developed by the Ocean Mapping Group (www.omg.unb.ca/~jhc/SwathEd.html) was used to correct for artifacts and errors that may have been introduced during data collection. This software also enhanced the corrected data by resolving beam pattern and aspect ratio distortions and by imposing a linear contrast stretch before it generated bathymetric and sidescan sonar image mosaics in a Mercator projection. All data processing described here is initiated using Silicon Graphics workstations as soon as each acquisition file is closed by the Simrad Mermaid workstation (usually at the end of each survey line). Additional processing was done in the lab to correct for fluctuations in sea level during the survey and for artifacts in the data files that were not corrected in the field (see below). (2) The processing and editing steps on board the ship were: (A.) Demultiplex, or unravel, the acquired Simrad data files using RT to generate separate files containing navigation, depth soundings, sidescan sonar backscatter values, and sound velocity information. (B.) Automatically reject bad data (autoRejectSoundings). For the multibeam soundings, reject data outside expected depth ranges (operator's decision based on nautical chart data); for navigation data, reject fixes with poor GPS statistics. (C.) Edit the navigation data on-screen using jview to remove undesirable points, including turns at the ends of survey lines. (D.) Edit the multibeam soundings on-screen using swathed to remove individual anomalous soundings. (E). Merge tidal information and the corrected navigation back (mergetide and mergenav) into the data files. Tidal information was obtained from predicted tides using the Xtide program http://www.flaterco.com/xtide/xtide.html), which generated predicted tides based on the harmonic coefficients for Chatham provided by the Xtide program. (F.) Map the bathymetric soundings from each processed data file onto a Mercator grid using weigh_grid (a SwathEd utility) with node spacings and scale selected by the operator. The grid file (capesouth.r4) was a floating point binary file. 98015_multibeam_data Unknown capesouth.r4 Bill Danforth U.S. Geological Survey Geologist mailing and physical address

384 Woods Hole Road

Woods Hole MA 02543-1598 USA (508) 548-8700 x2274 (508) 457-2310 bdanforth@usgs.gov Map the extracted sidescan sonar backscatter values onto a digital mosaic using the SwathEd utility mos2 in the Mercator projection, having a central longitude of -70.3166667 degrees West, a latitude of true scale of 41.65 degrees north and the horizontal datum is WGS84. capesouth.r4 Unknown capesouthmos_mer4m.tif Bill Danforth U.S. Geological Survey Geologist mailing and physical address

384 Woods Hole Road

Woods Hole MA 02543-1598 USA (508) 548-8700 x2274 (508) 457-2310 bdanforth@usgs.gov Raster Pixel 9833 3575 1 4.0000004.0000008Upper LeftFALSENone1pixel codesTRUETIFFmetersmeters255GeoTIFF row and column 4.000000 4.000000 meters Mercator41.650000-70.3166670.0000000.000000 D_WGS_1984 WGS_1984 6378137.000000000000000000 298.257223563000030000 GCS_WGS_1984Mercator There are no attributes associated with the GEOTIFF image. GeoTIFF image containing greyscale digital sidescan sonar mosaic from USGS/CMGP survey 98015. Pixel values contain acoustic reflectivity values normalized to an 8-bit data range (0-255). Low-backscatter is represented by dark tones (low values) and high-backscatter is represented by bright tones (high values). Lawrence J. Poppe U.S. Geological Survey Geologist mailing and physical address

384 Woods Hole Road

Woods Hole MA 02543-1598 USA (508) 548-8700 x2314 (508) 457-2310 lpoppe@usgs.gov Downloadable Data Although all data 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 related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. government. TIFF GeoTIFF GeoTIFF format backscatter mosaic, GeoTIFF world file and associated metadata zip archive 0.000 0.000 http://pubs.usgs.gov/of/2005/1048/data/backscatter/mosaic/mercator/capesouthmos_mer4m.zip http://pubs.usgs.gov/of/2005/1048/data/backscatter/mosaic/mercator/capesouthmos_mer4m.tif http://pubs.usgs.gov/of/2005/1048/htmldocs/data_catalog.htmhttp://pubs.usgs.gov/of/2005/1048/data/backscatter/mosaic/mercator/ Data are downloadable via the World Wide Web (WWW). DVD-ROM 4.7 Gbytes UDF None This image is available as a GeoTIFF image with an accompanying world file. To utilize this data, the user must have an image viewer, image processing or GIS software package capable of importing a GeoTIFF image. 2006 20060321 Lawrence J. Poppe U.S. Geological Survey Geologist mailing and physical address

384 Woods Hole Road

Woods Hole MA 02543-1598 USA (508) 548-8700 x2314 (508) 457-2310 lpoppe@usgs.gov FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 local time None None enhttp://www.esri.com/metadata/esriprof80.htmlESRI Metadata Profile Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.722capesouthmos_mer4m.tif26381.3540681.353837339.713798007.711-69.999976-69.82831441.96998241.6166481ISO 19115 Geographic Information - MetadataDIS_ESRI1.0dataset002file://\\FLORIDA-DESKTOP\OFR2005_1048\web-content\data\backscatter\mosaic\mercator\capesouthmos_mer4m.tifLocal Area Network0.000Raster DatasetMercator2135754unknown98334unknown2006032212482000200603221248200020060322