Advances in miniature, low-cost microelectronic and mechanical systems (MEMS) with limited onboard processing capabilities, storage, and short-range wireless communication links, together with the development of novel microsensors and sensor materials, enable us to build a new generation of technology that consists of large collections of tiny, untethered, battery-powered computing nodes with various sensing functions. With the continued trend toward miniaturization and the inexpensiveness of such sensor nodes, it is expected that sensor nodes will be [Page 1253]less than a cubic millimeter in size in the near future and that sensor networks can be made up of thousands or even millions of sensors (“smart dust”). Geosensor networks (GSNs) are a specialized application of wireless sensor network technology in geographic space to detect, monitor, and track environmental ...