Composite Grayscale Image of the Sidescan Sonar Data From National Oceanic and Atmospheric Administration (NOAA) Survey H11076 of the Sea Floor in Quicks Hole, MA (H11076_GEO_1MSSS.TIF, Geographic)

The sidescan sonar data was acquired with a Klein 5250 sidescan sonar tow fish set to sweep 100 m to either side of the launch tracks. The tow fish emits two 50-degree-wide beams tilted down 20-degree from horizontal, and transmits at 100 kHz. The data were acquired in XTF (extended Triton data format), recorded digitally through an ISIS data acquisition system, and processed using CARIS SIPS (Sidescan Image Processing) software for quality control, and to produce an image at 1-m resolution. As part of this process, the sidescan-sonar data were multiplexed and filtered to convert the data into the desired processing format and to remove speckle noise and to correct for slant-range distortions. Image 'shine through', to account for areas of overlap, and auto-contrast adjustment were applied. Tonal artifacts caused by inaccurate across-track normalization present on the sidescan-sonar imagery are minor. Contrast enhancement based on the dynamic range of the data was applied to the mosaic and it was then projected into UTM Zone 19 to produce the final enhanced image.

The image was imported into a graphics application and the grayscale was inverted to make hard returns light tones and softer returns darker tones.

The UTM Zone 19 GeoTIFF was reprojected into Geographic (Datum WGS 84) with the Blue Marble Geographic Transformer software.

Edits to the metadata were made to fix any errors that MP v 2.9.30 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). The source information was incomplete and had to be modified to meet the standard. Only the source media, time period of content, and source contribution were supplied. The geodetic model needed information added to meet the standard. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent.

Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog.

Added keywords section with USGS persistent identifier as theme keyword.