Enhanced Grayscale TIFF Image of the 1-m Sidescan-Sonar Data From National Oceanic and Atmospheric Administration (NOAA) Survey H11445 of the Sea Floor north of Plum Island, New York (H11445_SSS1M_GEO.TIF, Geographic, WGS84)

The sidescan-sonar data were acquired with Klein 5000 sidescan-sonar system hull mounted to a 29' aluminum launch deployed from the NOAA ship Thomas Jefferson. The system was set to sweep 100 m to either side of the launch tracks. The system has a vertical beam angle of 40 and transmits at 455 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 a composite sidescan-sonar image at 1-m horizontal resolution. As part of this process, the sidescan-sonar data were demultiplexed and filtered 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. Contrast enhancement based on the dynamic range of the data was applied to the mosaic and it was then projected into UTM Zone 18, NAD83 to produce the final enhanced image.

TIFF image was converted to 8-bit grayscale from 8-bit RGB and the grayscale was inverted such that high backscatter is white and low backscatter is black. Used Photoshop CS2.

Copied world file from h11445_SSS_100_1mRes_mosaic.tif and renamed as h11445_SSS_100_1mRes_mosaic_inv.tfw. Used GeoTiff Examine to add the georeferencing information to the header, making h11445_SSS_100_1mRes_mosaic_inv.tif a GeoTIFF.

ArcToolbox Project Raster Tool was used to project to Geographic WGS84 in ArcGIS 9.2. Used the following parameters: input: H11445_SSS_1mRes_mosaic_inv.tif, output: H11445_SSS_1m_geo.tif, output coordinate system: WGS84, transformation 1, bilinear resampling, output cell size default.

In ArcMap 9.2 exported TIFF using Data--Export Data from right clicking on TIFF name. Selected options use renderer and square, TIFF format, and default cell size.

Used Photoshop CS2 to convert black border created by projecting image to white and filled background with Paint Bucket tool.

Used GeoTifExamine to add the georeferencing information to the TIFF header, making the image a GeoTIFF. Renamed TIFF and associated files in ArcCatalog 9.2.

Used Define Projection Tool in ArcGIS 9.2 to define projection as Geographic WGS84, so ArcGIS recognizes the projection.

Edits to the metadata were made to fix any errors that MP v 2.9.32 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. Both geographic and a planar coordinate system were present so the planar one was removed. 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.

Added keywords section with USGS persistent identifier as theme keyword.