This dataset shows the extent of sidescan sonar data collected during acoustic surveys completed within and adjacent to the boundaries of Cape Cod National Seashore (CACO) from 2014-2015. Full coverage sidescan and partial coverage bathymetry data were collected using an Edgetech 6205 Phase-Measuring Sidescan Sonar. In total, 668 hectares were mapped at primarily 20 – 40 meter line spacing and 50 meter swath range to allow overlap of lines.

The side scan sonar survey was done simultaneously with the bathymetry swath survey and used an EdgeTech Model 4125 Towfish bow-mounted from Lookdown at 400 and 900 kHz. The 4125 Towfish utilizes EdgeTech’s Full Spectrum CHIRP technology to produce higher resolution images than a non-CHIRP system. EdgeTech Discovery Software was used to acquire the side scan sonar data using the JSF format at a resolution of about 2.3 cm. All JSF files collected using EdgeTech’s Discover Software were processed using John Gann’s Chesapeake Technology SonarWiz5. Dimensions of contacts should be considered accurate to +/- 30% of the measured dimensions. This system also records the direct arrival intensity data.

Polygon shapefile showing the coverage area of the acoustic mapping at Sandy Hook, NJ between July 2015 and August 2015. The side scan sonar survey was done simultaneously with the bathymetry swath survey and used an EdgeTech Model 4125 Towfish bow-mounted from Lookdown at 400 and 900 kHz. The 4125 Towfish utilizes EdgeTech’s Full Spectrum CHIRP technology to produce higher resolution images than a non-CHIRP system. EdgeTech Discovery Software was used to acquire the side scan sonar data using the JSF format at a resolution of about 2.3 cm. All JSF files collected using EdgeTech’s Discover Software were processed using John Gann’s Chesapeake Technology SonarWiz5. Dimensions of contacts should be considered accurate to +/- 30% of the measured dimensions. This system also records the direct arrival intensity data.

This dataset presents the processed sidescan mosaic for Fire Island National Seashore. The acoustic sonar survey was conducted using a EdgeTech 6205, a Multi-Phase Echo sounder system. This combined bathymetry and dual-frequency sidescan sonar system is optimized for shallow water surveying. The sonar system was bow-mounted to a 28-ft pontoon survey vessel customized for shallow water surveying, including having a draft of less than one foot. Data was collected using GeoDas software developed by Ocean Imaging Consultants (OIC) and monitored topside in real-time to ensure quality of data and full-coverage sidescan was being achieved. The data were collected in association with an Applanix POS MV system to assure positional accuracy and to correct for vessel motion (pitch, roll, heave). The survey was designed to acquire full-coverage sidescan data and partial coverage bathymetry data. As such, the survey was composed of parallel track lines with line spacing of 35 to 50 m and a sonar swath range of 50 m (25 m per side) to ensure overlap with adjacent lines. The raw sidescan and bathymetry records were processed using OIC CleanSweep software (Version 3.8.0, Build #263). All of the acoustic data were examined manually to confirm quality and accuracy. For sidescan, processing followed standard techniques of bottom-tracking the data and then applying angle-varying gains (AVG) and look-up tables (LUT) as necessary to correct for water column returns, arrival angle, and contrast to produce color-balanced sidescan sonar images. The native images are displayed as an inverse gold color scale, with pixel values ranging from zero (dark gold) to 255 (white). The lighter pixels indicate hard acoustic returns and represent the presence of hard surficial sediments (e.g. coarse sand, cobbles, and boulders), whereas darker pixels represent the presence of soft sediments, which tend to absorb sound to a greater degree. The horizontal coordinate system was set to UTM Zone 18N and sidescan data was processed to 25cm pixel resolution.

Mapping extent of acoustic surveys completed along the 58‐km long Assateague barrier island stretching from the Ocean City inlet in Maryland, down past Chincoteague Island in northern Virginia. The data was collected June 20th-25th, 2014 and May 12th - 21th, 2015. Full coverage side-scan sonar and partial coverage bathymetry data were collected using an EdgeTech 6205 Multiphase Echosounder. In total, 73 square kilometers were mapped at primarily at 100m line spacing and 80 m swath range per channel (to allow overlap between lines).

This data layer is an interpretation of the sidescan sonar mosaic from the study area off New London, CT.

This CD-ROM contains digital high resolution sidescan-sonar data collected during USGS cruise ALPH98013 aboard the F/V Alpha & Omega II. The coverage lies within the New York Bight Apex, offshore the Long Island and New Jersey coasts. This CD-ROM (Compact Disc-Read Only Memory) has been produced in accordance with the ISO 9660 CD-ROM Standard and is therefore capable of being read on any computing platform that has appropriate CD-ROM driver software installed. Access to the data and information contained on this CD-ROM was developed using the HyperText Markup Language (HTML) utilized by the World Wide Web (WWW) project. Development of the CD-ROM documentation and user interface in HTML allows a user to access the information by using a variety of WWW information browsers (i.e. NCSA Mosaic, Netscape) to facilitate browsing and locating information and data. To access the information contained on this disk with a WWW client browser, open the file 'index.htm' at the top level directory of this CD-ROM with your selected browser. The HTML documentation is written utilizing some HTML 3.0 enhancements. The disk should be viewable by all WWW browsers but may not properly format on some older WWW browsers. Also, some links to USGS collaborators are available on this CD-ROM. These links are only accessible if access to the Internet is available during browsing of the CD-ROM. The archived sidescan-sonar data may be downloaded and processed. Software is available on this CD-ROM for viewing the individual swaths using computer systems running the UNIX operating system.

In April of 2010, the U.S. Geological Survey (USGS) conducted a geophysical survey from the east end of West Ship Island, MSiss., extending to the middle of Dauphin Island, Ala. This survey had a dual purpose: (1) to interlink previously conducted nearshore geophysical surveys (shoreline to ~2 kilometers, km) with those of offshore surveys (~2 km to ~9 km) in the ares and (2) to extend the geophysical survey to include a portion of the Dauphin Island nearshore zone. The efforts were part of the USGS Gulf of Mexico Science Coordination partnership with the U.S. Army Corps of Engineers (USACE) to assist the Mississippi Coastal Improvements Program (MsCIP) and the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazards Susceptibility Project by mapping the shallow geological stratigraphic framework of the Mississippi Barrier Island Complex.

This dataset contains sediment grain-size classification data develop from during acoustic surveys completed along the 58‐km long Assateague barrier island stretching from the Ocean City inlet in Maryland, down past Chincoteague Island in northern Virginia. The data was collected June 20th-25th, 2014 and May 12th - 21th, 2015. Full coverage side-scan sonar and partial coverage bathymetry data were collected using an EdgeTech 6205 Multiphase Echosounder. In total, 73 square kilometers were mapped at primarily at 100m line spacing and 80 m swath range per channel (to allow overlap between lines).

This GIS layer contains the shiptrack navigation collected aboard the RV ASTERIAS during a 1981 geophysical cruise to Block Island Sound and easternmost Long Island Sound.