Tradespace Analysis of GNSS Space Segment Architectures

Global navigation satellite systems (GNSS) provide ubiquitous, continuous, and reliable positioning, navigation, and timing information around the world. However, GNSS space segment design decisions have been based on the precursor Global Positioning System, which was designed in the 1970s. This article revisits those early design decisions in view of major technological advancements and new GNSS environmental threats. The rich tradespace between user navigation error (UNE) performance and constellation deployment costs is explored and conclusions are complemented by sensitivity analysis and association rule mining. This article finds that constellations at an orbit altitude of ~2 earth radii can outperform existing GNSS in terms of cost, robustness, and UNE. These insights should be taken into account when designing future generations of GNSS.