Visualization of Large Geospatial Data Sets

The Earth Resources Observation and Science (EROS) Center of U.S. Geological Survey EROS is currently managing and maintaining the world largest satellite images distribution system, which provides 24/7 free download service for researchers all over the globe in many areas such as Geology, Hydrology, Climate Modeling, and Earth Sciences. A large amount of geospatial data contained in satellite images maintained by EROS is generated every day. However, this data is not well utilized due to the lack of efficient data visualization tools. Therefore, it will be beneficial to design a geo-visualization tool which allows EROS staff and global users to visualize the properties of download requests for the satellite images maintained on EROS web servers. This paper describes a method for visualizing various characteristics of the satellite image download requests. More specifically, Keyhole Markup Language (KML) files are generated which can be loaded into an earth browser such as Google Earth. Colored rectangles associated with stored satellite scenes are painted onto the earth browser; and the color and opacity of each rectangle is varied as a function of the popularity of the corresponding satellite image. An analysis of the geospatial information obtained relative to specified time constraints provides an ability to relate image download requests to environmental, political, and social events. * Corresponding author. Please direct questions concerning this article to Dr. Ziliang Zong at [email protected]. More detailed information about this project can be found at http://www.mcs.sdsmt.edu/zzong/.