Distributed Arrays of Small Instruments (DASI)

The coupled layers of Earth's upper atmosphere, ionosphere, and magnetosphere form an interacting system. Continuous observations of the characteristics and features of this system are needed to study, understand and predict its effects. Arrays of ground-based instruments fielded to produce continuous overlapping observations of these important regions, combined with innovative signal-processing and display techniques, are providing a new look at Earthspace. The NAS Solar and Space Physics Decadal Survey has recommended that the next major ground-based instrumentation initiative for space science research be the deployment of widely-distributed arrays of small instruments. Such arrays will provide continuous real-time observations with the resolution needed resolve mesoscale phenomena and their dynamic evolution. The ground-based DASI program (Distributed Arrays of Small Instruments) provides an opportunity to address the earthward boundaries of the space weather connection. DASI will address the need for observations to support the next generation of space weather data-assimilation models and will push our understanding of the physical processes which interconnect the spheres of Earthspace to a new level. This next-generation space research program involves synergy with cyberinfrastructure development, since DASI has strong needs in this area in order to communicate and coordinate distributed instrument and research activities from around the world. As this program develops over the next decade, it is envisioned that DASI instrumentation will provide real-time data for a wide variety of research, applications, and educational users.

At the Haystack Observatory, work has begun to address these problems using distributed ground-based instrument arrays. The network of GPS receivers is providing a capability to map the overlying ionosphere and to investigate the effects of solar storms on communications and navigation systems. A distribution of ISIS software radio receivers is being fielded to study the electric fields which drive the ionospheric effects, as well as to observe the characteristics and severity of their space weather impact.