CHAPTER 8 - VISUALIZING LONG ISLAND SOUND DATA LAYERS USING GEOGRAPHIC MAPPING TOOLS

Chris Polloni¹ and Mary L. DiGiacomo-Cohen<sup>2

1</sup>U.S. Geological Survey, Woods Hole, MA 02543
²Long Island Sound Resource Center, Connecticut Geological and Natural History Survey,
Department of Environmental Protection, 1084 Shennecossett Road, Avery Point, Groton, CT 06340

In creating this CD-ROM some of the goals included: 1) to provide users with the ability to visualize inter-disciplinary information in a geographic context (Polloni et al, 1995),  2) to provide maps in flexible scales for basin-wide synthesis (Kenwood et al, 1996; Polloni et al, 1998), and 3) to give the user the ability to identify and query geographic and attribute data (Polloni, 1998ab).  The primary effort was to deliver the original sidescan sonar mosaics in their highest possible resolution as geo-referenced imagery so that they could be used as basemaps for other digital data from the Long Island Sound region.  Project files are included which already have the inter-disciplinary data layers loaded as theme coverages.  The user can turn data layers on or off,  measure distances in user specified units, and add, if available, other user specified themes as long as they are in the same coordinate system (i.e. latitude and longitude in decimal degrees).   Coverages in state plane or other coordinate systems must be reprojected to be compatible with data on this CD-ROM.

We have provided the GIS ArcExplorer version 1.1 software so that a user with a compatible operating system can down-load it to their own system and use it to display the coverages provided.   ArcExplorer is compatible with ArcView and has the ability to link to coverages on the CD-ROM and also, if connected to the WWW, to coverages which may be available on GIS web servers such as the State of Connecticut Maps and Geographic Information Center (MAGIC).   A Manual for ArcExplorer Version 1.1 is also provided in Adobe Acrobat (PDF) format.  The user must have the Adobe Acrobat software installed to read the ArcExplorer manual.  The user is encouraged to get the latest version of the ArcExplorer and Adobe Acrobat software directly from ESRI and Adobe, respectively, on the WWW.  Separate project files are included for both ArcExplorer and ArcView.   If you have loaded ArcExplorer, you can click on LISSEXPL.aep and this mapping tool will display the data selected.  If you have ArcView version 3.0 or higher on your computer, you should be able to click on the LISSARCV.APR project file and have the coverage appear on your screen once you have defined the CDROM path name.  On the ArcView project file we have defined the user variable "CDROM" as the drive letter of the CD-ROM drive.  To use the ArcView project file the user must define this variable.

SET CDROM=(Use the drive letter assigned to you CDROM drive):       Example for CDROM e:  "SET CDROM=E:"

Once the CDROM path variable has been added to your autoexec.bat file you must reboot the system.

For Windows NT users:

This setting is defined in the Control Panel System environment window - (ie. assign user variable CDROM to E:)

Although the data assembled on this CD-ROM comes from a variety of sources,  we have translated the data layers to be compatible with the desktop mapping tools ArcExplorer and ArcView from ESRI.   The contributors to this CD-ROM have provided sidescan sonar, texture, and bathymetry data for integration and viewing;  additional layers have been included (coastline, state boundaries) for regional reference purposes.  All data has an attached metadata file for source and quality definition.  All data with attributes can be queried to display as much as is available in the individual records.  Originally, the sediment data theme coverage was a very large uncompressed (30Mbytes) file.  We have included it as a 1-Mbyte compressed file (sedbzip).    When the sediment data theme is selected, it is read and a request is made for the user provide a specified directory space (typically c:\seddb created in advance) for the expanded file set. 

A set of project files for ArcExplorer and ArcView are included so that the user can use them directly.  The project files assume the user CD-ROM drive designation is D.   If the user drive has a different designation, the user must edit the project file.   The ArcExplorer user manual has detailed instructions for editing the project file on page 64.  The project files have links to the data layers provided on the CD-ROM and these links can be switched on and off.  ArcExplorer has been included on this CD-ROM for off-loading to a users computer system.  Instructions for set-up on the users computer system are included in the ArcExplorer user manual.  To install the ArcExplorer software, click on the highlighted "ArcExplorer version 1.1" software link.   Windows will inform the user that this may be downloaded or  run from its current location.  The application will install if the user selects the run from current location and follow the instructions for the complete install.  If you have a browser that only has an option to download (ie NETSCAPE), then the user must download the file (aeclient.exe, 7Mbyte) and execute the file under their operating system.   aeclient will install ArcExplorer 1.1 and provide a shortcut for the user to restart the software. Once ArcExplorer is loaded, the user may use the project file (LISSEXPL.aep) to add the primary set of data themes.  Other data themes that are in the same coordinate system may be added at this time.  If the user has ArcView, the project file (LISSARCV.APR) can be used. 

 REFERENCES

Polloni, C.F., Schmuck, E.A., Denny, J.F., Prisloe, M.P., and Babb, I.G., 1995.   Marine Geologic Atlases on CD-ROM, A Method of Assembling, Integrating and Displaying Information: Northeastern Section GSA Abstracts with Programs, Cromwell, CT, Vol. 27, no. 1, p. 74.

Kenwood, Clifford, Manheim, F.T., Polloni, C.F., and Williams, S.J., 1996.  An Environmental and Geological  Bibliography for Lake Pontchartrain:  U.S. Geological Survey Open-File Report 96-527, CD-ROM.

Polloni, Christopher, Tripp, B., and Truesdale, P., 1998.  An Illustrated Environmental Bibliography for Buzzards Bay, Massachusetts.  U.S. Geological Survey Open-File Report 98-50 CD-ROM.

Polloni, Chris, 1998a,  Mapping tools for CDs and the Web, GRIPS' 98, session chair, in session listing of the SIGCAT'98 CD/DVD Conference and EXPO, Baltimore, MD, May 17-22, 1998.

Polloni, Chris, 1998b, HTML - XML: An Effective Authoring tool for today's CDs: in Session listing of the SIGCAT'98 CD/DVD Conference and EXPO, Baltimore, MD, May 17-22, 1998.