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Author: Robert M Cheetham 1234 Market St Phone: 215-686-5921 While visualization of phenomena through a spatial metaphor has been significantly enhanced by GIS technology, understanding the structure of spatial phenomena as they change in time still represents a challenge. Only recently have database vendors begun to provide the tools and data structures necessary for the creative manipulation of time-stamped data. Extensions such as ArcView Tracking Analyst and the tracking layer object in MapObjects have begun to enable visualization of this type, but these tools can be extended. The City of Philadelphia Police Department, GIS Services Group, and Health Department have begun developing a set of applications using MapObjects and ArcView Spatial Analyst that enable visualization of point and GRID data from air quality and crime data. The air quality data has been collected over 30 years from detectors spread across the City and includes NOx, CO, SO2, ozone, and various particulate measures. The crime and other incident data is drawn from the two million unique incidents per year to which the Police Department responds. The paper will demonstrate these applications, discuss the development process, and suggest future directions for this research. |
