Framework and techniques for cooperative group situational awareness in urban environments

Society has become increasingly dependent upon GPS-based positioning even in urban environments where dense, high-rise landscapes create challenging signal blockages and unintentional interference. This paper builds upon a previously developed tool, designed to enhance GPS situational awareness by integrating multi-user GPS receiver position and signal reports with predictions, reference orbits and clocks, and potentially other reference data reported to a regional supervisor or monitor. The current work focuses specifically on extending this capability to the challenging urban environment. Predictions of the effects of building obstructions and reflections on GPS signal reception are constructed and compared with experimental data sets collected with cell phones in Denver, Colorado. With the framework and interface structure established, the tool can be used to analyze data within an urban environment.