Geographic Information System

Data layers in this report are provided with geographic coordinates to allow the data to be integrated into a GIS.  A GIS is defined as a system of hardware and software to support the display, manipulation, and analysis of spatial data for mapping and complex data solving. This package provides researchers the ability to integrate, analyze, and map multiple datasets to help local managers make decisions on the basis of the environmental effects of proposed economic and social policies.

Data layers archived here should not require additional processing to be used in the Environmental Systems Research Institute's (ESRI) ArcView and ArcGIS software. This does not mean that a user will not wish to do additional processing, especially with a different GIS software package or spheroid, but that it is not necessary to do additional processing simply to use the data in its minimum archive format.

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 the displaying of spatial data. The user will need to add the selected data layers by using ArcExplorer's add data button. 

Data Description

This report includes links to several data layers (or themes) that can be used to create views of the Plum Island study area. GeoTIFF files produced from the NOAA sidescan-sonar and bathymetric surveys are provided in geographic WGS84 and Universal Transverse Mercator (UTM) Zone 18 NAD 83 projections. GeoTIFFs of the bathymetry are in color and are hill-shaded; GeoTIFFs of the sidescan imagery are in grayscale. ArcRaster grids of the multibeam bathymetric data are provided at 2-m resolution in both geographic (WGS84) and UTM, Zone 18 (NAD 83) projections.

Ancillary vector data that are provided in the Geographic Coordinate System in WGS84 (GCS WGS84) datum consist of polygon data layers that provide: (1) a base map of the coastline for the Long Island Sound GIS project area; (2) an outline of the study area; and (3) interpretations of sea-floor features. Point data layers, also in GCS WGS84, are provided for the sediment data and locations of bottom photos. The photographic data are provided in both mid- and full-resolution JPEG image format.

The top level of this report on the CD-ROM contains an ArcView project file (h11445.apr) created in ArcView 3.3 and an ESRI ArcMap document (h11445.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.

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, h11445_mb2m_utm.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 (there is no browse graphic for the navigation data).

Federal Geographic Data Committee metadata for the individual data layers is provided in HTML, FAQ HTML, and text versions in the table below. In addition to these formats of the metadata, the WinZip files contain the XML version of the metadata viewable in ArcCatalog. Selecting associated metadata files from the table 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 by using the Windows program WINZIP v8.0. Users who do not have software capable of uncompressing the archived files may obtain a free version from Pkware, Inc.

BATHYMETRIC IMAGERY

BATHYMETRIC GRIDS

SIDESCAN-SONAR IMAGERY

VERIFICATION DATA LAYERS

NAVIGATION DATA LAYER

INTERPRETIVE DATA LAYER

BASEMAP DATA