Mobile ad hoc networks for in situ atmospheric sensing

ENSCO, Inc. is developing on innovative atmospheric observing system known as global environmental micro sensors (GEMS). The GEMS concept features in situ airborne buoyant probes that can take measurements over all regions of the Earth. The probes will communicate with other probes and remote ground and/or space-based receiving platforms using radio frequency transmissions to form a wireless network of passive Lagrangian drifters. For a successful GEMS system, the most important network function is to relay timely data to one or more receiving stations. In this paper, we describe both the GEMS system and probe design as well as discuss the trade-offs associated with optimizing a three-dimensional, mobile, airborne network comprised of low-cost, low-power probes. We also analyse and present measured data to determine the performance of a representative GEMS prototype system under actual environmental conditions and various aspects of mobility.