GPS & Space Weather: Understanding the Vulnerabilities and Building Resilience

Since the last solar maximum, societal dependence on the Global Navigation Satellite System (GNSS) has increased substantially. Critical applications such as aviation, highway traffic management, precision agriculture, marine navigation, and emergency response all require and depend almost solely on GNSS services. As our national critical infrastructure and economy are increasingly dependent on positioning, navigation, and timing (PNT), our society is vulnerable to disruptions that can be caused by space weather. It is understood that space weather is the largest contributor to single-frequency Global Positioning System (GPS) errors and a significant factor for differential GPS errors. Yet several scientific challenges remain to keep up with the pace of the GPS industry and users: how to better predict the state of the ionosphere and how to better predict the magnitude of the next solar cycle. Worse still, assessment of GPS-related societal vulnerabilities and identification of coping strategies are attempting to hit a moving target—the emergence of GPS as a technology and its use by society are rapidly evolving in a short time compared to a single solar cycle. So, how can we gain a better understanding of what exactly is the GPS industry's vulnerability to space weather? What can the public and private sectors do to create a better path for moving forward? To address these concerns, the American Meteorological Society (AMS) Policy Program is conducting a policy study, funded by the National Science Foundation, on space weather and GPS policy issues. A two-day workshop in October 2010 in Washington DC will lead to recommendations on how to best characterize satellite navigation's vulnerability to space weather and how to build resilience for the future. This presentation will discuss outcomes of the workshop and the following issues: (1) How does space weather affect GPS technologies and services? (2) What is the impact of such effects on users who depend upon GPS? & (3) What policy options are available for building societal resilience to these adverse effects?