UWB (Ultra-Wide Band)- and GNSS (Global Navigation Satellite System)-based real-time positioning methods have been the subject of extensive research and perform well in their respective optimal environments. However, their optimal environments are largely mutually exclusive in practical applications; a cost-effective ubiquitous indoor/outdoor positioning system must utilize both systems to provide reliable positioning information in all environments. At the same time, there is no need to consider GNSS information in GNSS-denied areas (indoors) with UWB coverage. Therefore, a switch between the systems as the definitive positioning information source is needed. This paper outlines some approaches to transitioning between UWB and GNSS positioning of an unmanned ground vehicle (UGV).