Color Shaded-Relief GeoTIFF Image Showing the 0.5-m Bathymetry Generated from National Oceanic and Atmospheric Administration (NOAA) Survey H11077 in Woods Hole, MA (H11077_MB0.5M_GEO.TIF, Geographic)

The multibeam data were acquired in XTF (extended Triton data format) and recorded digitally through an ISIS data acquisition system. A Reson 8101 echosounder hull-mounted on a 29' launch deployed from the NOAA ship Whiting was used to acquire the sounding data. These data were processed using CARIS HIPS (Hydrographic Image Processing System) software for quality control, to incorporate sound velocity and tidal corrections, and to produce a base surface at 0.5 resolution. Sound velocity corrections were derived using frequent SEACAT CTD (conductivity-temperature-depth) profiles. Typically, a CTD cast was conducted every four to six hours of multibeam acquisition. Tidal zone corrections were calculated from data acquired at the Nantucket tidal gauge. The vertical resolution of the multibeam data is approximately 0.5% of the water depth.

The ASCII grid was opened in Fledermaus, a gridded surface with a cell size of 0.5 m was created, and it was exported as an ArcView ASCII grid.

The ArcView ASCII grid was opened in ArcMap 9.2 and exported as an ESRI binary grid.

The bathymetry grid was reprojected from UTM zone 19, NAD83 to geographic WGS 84 using transformation 1 with the ArcGIS 9.2 Project Raster tool.

A hill-shaded grid of the bathymetry was created using ArcToolbox's Hillshade tool using an azimuth of 45 degrees, an altitude of 45 degrees, and a z factor of 0.00001171. The bathymetry grid was overlain on the hill shade with 40% transparency. A GeoTIFF image that represents the hill-shaded bathymetry was exported (file, export map) from ArcMap 9.2.

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, the planar one was removed with the resolution transferred to the geographic. 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.