Much of the information that underpins the challenges facing society today-such as terrorist activities, global environmental change, and natural disasters-is geospatial in nature. An everyday example of key geospatial data is the location of a cell phone user who has dialed 911 in an emergency. In terrorist situations, the origins and destinations of phone calls, travel patterns of individuals, dispersal patterns of airborne chemicals, assessment of places at risk, and the allocation of resources are all geospatial data. As the volume of geospatial data increases by several orders of magnitude over the coming years, so will the potential for corresponding advances in knowledge of our world and in our ability to react to changes taking place. This article, which discusses key research challenges in location-aware computing, is excerpted from IT Roadmap to a Geospatial Future (SEE NRC REPORTS SIDEBAR). The report outlines an interdisciplinary research roadmap focusing on challenges in location-aware computing, databases and data mining, and human-computer interaction technologies. The convergence (SEE FIGURE 1.1) of advances in these three areas, combined with a sharp increase in the quality and quantity of geospatial information, promises to transform our world. Geospatial data have become of critical importance in areas ranging from crisis management and public health to national security and international commerce. The Just-in-Time Mapping Scenario (SEE SIDEBAR) illustrates the committee's vision of what is possible with integrative, multi-disciplinary research efforts. Diverse technological advances will be needed to achieve this imaginative future. Advances in databases could improve our ability to integrate geospatial data (which is often of myriad formats, conventions, and semantics) and to represent objects, such as a wildfire, that move and evolve over time, sometimes appearing or disappearing at irregular intervals. Analysis and evaluation of data would benefit from new data mining methods designed to operate on complex, highly dimensioned data representing objects that may be undergoing continuous change. New technologies that support human interaction with geospatial data would enable individuals from geospatial information specialists to policy makers to emergency response personnel to access, visually explore, and construct knowledge from geospatial data and apply the knowledge to critical problems facing both science and society. A brief synopsis from IT Roadmap to a Geospatial Future of key research directions in databases, data mining, and human-computer interaction is outlined at the end of the article. This article focuses on research opportunities in location-aware computing. Advances in this area could have important implications not just for how geospatial data are acquired, but also for how and with what quality they can be delivered, and how mobile and geographically distributed systems are designed. Sensors that record their location and some information about the surrounding environment (e.g., temperature and humidity) are being deployed to monitor the state of roads, buildings, agricultural crops, and many other objects. For example, Smart Dust sensors (devices that combine microelectromechanical sensors with wireless communication, processing, and batteries into a package about a cubic millimeter in size)-currently in their infancy-can be deployed along remote mountain roads to determine the velocity and direction of passing vehicles or can be attached to animals or even insects to record where they travel (Pister, 2002) . The data transmitted wirelessly in real time from these sensors increase not only the volume but also the complexity of available geospatial data.
The major challenges in geo-spatial computing were covered in the summary of the recent NRC's IT roadmap to a geo-spatial future REF .
Challenges in location-aware computing
IEEE Pervasive Computing
Computer Science