Masking and multipath analysis for unmanned aerial vehicles in an urban environment

Unmanned Aircraft System (UAS) navigation in urban environments using Global Navigation Satellite System (GNSS) as a primary sensor is limited in terms of accuracy and integrity due to the presence of antenna masking and signal multipath effects. In this paper, a GNSS Aircraft-Based Integrity Augmentation (ABIA) system is presented. This system relies on detailed modeling of signal propagation and multipath effects to produce predictive and reactive alerts (cautions and warnings) in urban environments. The model predictive capability is then used to augment path-planning functionalities in the UAS Traffic Management (UTM) context. The models of the presented system are corroborated by performing simulation case studies in typical urban canyons, wherein positioning integrity is degraded by multipath and masking.