Date of Award

Fall 12-1-1999

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Geography, Geology, and Anthropology

First Advisor

Paul W. Mausel

Second Advisor

William Dando

Third Advisor

William D. Brooks

Abstract

This research focuses on developing a new output system that compacts maps in multiple projections into a single Geographic Information System (GIS) without visual errors, through constructing a discrete GIS database that is managed by a Relational Data Base Management System (RDBMS). Unlike in a traditional large GIS database, the data are "physically discrete but logically continuous." In a new discrete GIS database, every map keeps its individuality without a relationship to any other map, and the relationships among the maps are centrally managed by a RDBMS. A study site was chosen at the boundary of the state of Indiana and the state of Ohio. Some of the maps in the site are in a transverse Mercator projection and the other maps are in a Lambert conic projection. A single discrete database was established with these two map projections, without implementing a map projection unification. An algorithm named Jiang's Compactor for Multiple Map Projections was developed. The Jiang's Compactor successfully displayed the discrete data as a coherent entity without visible visual errors caused by the two map projections. Moreover, an algorithm was developed to process the discrete database in automation by connecting an Oracle RDBMS with ARC/INFO. The automated processing has been proven a success. This newly developed technology will support constructing a large GIS in a discrete manner using multiple map projections, resulting in saved time and labor by avoiding data projection transformations. This technology will improve the computing efficiency of a computer for handling large volumes of data by continuously inputting streaming small amounts of data. Data redundancy will be avoided for a large GIS by establishing a GIS database as an open system, which allows direct data access without physical data replication. The methodology developed will allow a large GIS, even a global GIS, to be formed in a simple, straightforward, and efficient way. The experiment on the study site has proven the feasibility of the new methodology as a practical new technology.

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