A Computationally Efficient Technique for the Improvement of the Display of Geospatial Information Stored in Geographic Coordinates
NAVAL RESEARCH LAB STENNIS SPACE CENTER MS MAPPING CHARTING AND GEODESY BRANCH
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Geographical Information Systems GIS frequently store positional information in geographic coordinates i.e., degrees of latitude and longitude. As a result, when GIS data are displayed on a video terminal, it is a usual practice to display the information un-projected with the view window x and y axis scaled in decimal degrees with degrees of longitude and latitude having the same scale factor on each axis. While this practice results in fast display time, avoiding the computational load imposed by complex cartographic projections, it results in a display that distorts the spatial relationships of the elements displayed on screen unless the displayed area is near the equator. A simple method is proposed as an alternative that greatly improves the display fidelity without adding any significant additional computational load. 6 figures, 3 refs.