The design of this CD-ROM is such that the user should not need any special software or hardware (except a recent web browser and a reasonably fast computer) to view the data. This is why the Interactive GIS html (HyperText Markup Language) pages are included. However, to do data manipulation and analysis, a GIS software package is probably easier to use. This project used ESRI's products (Arc/Info and ArcView) to do the final processing of these data. Although queries and displaying of the data is very simple in any of ESRI's software programs, GIS software is not necessary for all the data presented on the CD-ROM. The following sections might provide useful information:
The raster data - Sidescan sonar imagery and sediment sample pictures can be viewed with just about any graphics software package. Some sidescan sonar imagery contains registration information (in the case of the 'geotifs') and all the images have associated world files to allow geographic registration of the images (TFW for the TIFF images, JGW for the JPEG images). There are many GIS software packages capable of displaying georeferenced imagery.
Sediment sample data - each of the datasets represented on this CD-ROM as an ArcView shapefile has an associated DBF file. This DBF (database) file contains all of the attribute information for the sediment data. Included as attributes with each sediment sample point is the Latitude and Longitude of the sample location. Many spreadsheet programs, such as Microsoft Excel, are capable of importing DBF files.
FREE GIS DATA BROWSER - for those people who don't have a GIS data browser on their computer, a free viewer (ArcExplorer) is available from ESRI. ArcExplorer is limited to Microsoft Windows operating systems and has versions for Windows 95/98 or NT.
And if you are already ArcView compatible...
The data directory of the CD-ROM contains an ArcView project file called dataview.apr which was created on a Windows95 system using Arcview 3.1. Either double-click on the filename to launch ArcView, or open ArcView version 3.1 (or higher) and load the project. The project file has been modified to reflect relative pathnames to files, so it should work from the CD-ROM drive, regardless of the assigned drive letter.
Unfortunately, image catalogs created for the numerous sidescan-sonar images do not seem to stay with the project once saved. These image catalogs were created with the sample 'imgcat.ave' script, and then modified to remove absolute path names. Although the catalogs do not stay with the saved project, they can easily be loaded to make viewing the sidescan-sonar imagery easier than loading all the individual image files. These image catalogs are located in the directory data/sidescan/geojpgs/enhanced and can be added as an image theme in arcview. There are eight dbf (image catalog format) files that cover the entire study area. The filenames reflect the sub-area and year in which the data were collected. The filenames are as: ar197.dbf, ar198.dbf, ar297.dbf, ar298.dbf, ar397.dbf, ar398.dbf, ar497dbf and ar498.dbf.
The background of the sidescan-sonar imagery is white. To view only the imagery, and not the background, click on the legend of the image and turn the value 255 to transparent.
IMAGE FILES - If you want to download the sidescan sonar image files from the CD-ROM, simply copy them from their directory on the CD-ROM to the location of your choice. The data listing indicates the location of specific files. All of the TIFF sidescan sonar images have been compressed using the common 'GZIP' format to save disk space. These files will need to be uncompressed with the 'GZIP' program specific to the user's computer platform (the free software can be downloaded from www.gzip.org) or with another software capable of deciphering the 'GZIP' format (such as Winzip from www.winzip.com). If the georeferencing information is necessary for the downloaded files, be sure that your software can handle 'geotif' format for the TIFF images, or download each file's associated TFW world file. For the JPEG images, the georeferencing information is stored in the JGW file.
SHAPEFILES - Although shapefiles can also be copied directly to disk, care needs to be taken to ensure all of the files necessary to open each shapefile are transferred. For this reason, it is recommended that the shapefiles be transferred using ArcView's data manage.
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