Geographic Information System

This report contains geographic information system (GIS) data in vector and raster format. The vector data are provided in shapefile format compatible with Esri ArcView and ArcGIS software. These data are in the World Geodetic System of 1984 (WGS84) coordinate system. The raster data are provided in GeoTIFF format and Esri binary grid format. These raster data are provided in the WGS84 coordinate system and a UTM Zone 18 projection on North American Datum of 1983 (NAD83) vertical coordinate system. The WGS84 and NAD83 datums are used to remain consistent with earlier reports. Data layers provided as supplement to this report should not require additional processing to be used in Esri software.

For users who do not have the Esri software or a compatible GIS data browser available on their computer, a free viewer, ArcExplorer, is available from Esri. The key functionality of ArcExplorer is to display spatial data. The user will need to add the selected data layers by using the add data function of ArcExplorer.

Data Description

This report includes links to several data layers (or themes) that can be used to create views of the study area in northeastern Long Island Sound. GeoTIFFs of the bathymetry are provided as color hill-shaded relief images. ArcRaster binary grids of the original multibeam bathymetric data, which have gaps of no data between many of the lines in shallower areas, are included at a 2-m resolution. These data were also gridded to 10 m, interpolated to fill in the gaps, and merged with the 2-m data to provide datasets with a more continuous perspective. The sidescan sonar imagery is provided at 1-m resolution.

Ancillary vector data consist of (1) polygon data layers that provide base maps of the coastline for the Long Island Sound GIS project area, an outline of the survey area, an interpretation of sea-floor sedimentary environments, and an interpretation of sea-floor features; and (2) point data layers of the sediment data and locations of bottom photos. The photographic data are provided in mid- and full-resolution JPEG image format.

Each GIS data layer from this publication is cataloged below for easy access. The individual data layers are described below and include the GeoTIFF, grid, or shapefile name (for example, h12013_2m_utm18.tif), which is linked to a browse graphic showing the data-layer extent and coverage. Selecting the data-layer name will result in the browse graphic being displayed in a separate browser window.

The root level of this report on the DVD-ROM contains an ArcView project file (h12013.apr) created in ArcView 3.3 and an Esri ArcMap document (h12013.mxd) created in ArcMap 9.2, but saved as an ArcMap 9.0/9.1 document to make it accessible to older versions of the software.

Federal Geographic Data Committee (FGDC) metadata for the individual data layers are provided in HTML, a frequently asked questions (FAQ) HTML, and text versions. Selecting associated metadata files from links in the catalog below will open the information in a new browser window.

A compressed (.zip), downloadable archive file containing the components of the shapefile, grid, or image for each data layer is also provided. Compressed, downloadable files were created using WinZip 8.0 for Microsoft Windows. Users who do not have software capable of uncompressing the archived files may obtain a free version of the software from Pkware, Inc.

BATHYMETRIC IMAGERY

BATHYMETRIC GRIDS

SIDESCAN SONAR IMAGERY

VERIFICATION DATA LAYERS

INTERPRETIVE DATA LAYERS

BASEMAP DATA

NAVIGATION DATA LAYER

Also included in the data catalog of this report are the NOAA Descriptive Report (h12013_dr.pdf) and the NOAA Data Acquisition and Processing Report (OPR-B370-TJ-09_DAPR.pdf), which contain detailed descriptions of the data-acquisition and data-processing methods used in this study.

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