I. Introduction
Multi-agent networks have attracted an ever increasing attention in sensing and exploration applications, thanks to the increased exploration efficiency due to collaboration and the capability of observation from different points of view. The ability of ubiquitous navigation is essential for a multi-agent network. A typical navigation problem involves positioning, i.e., estimating the position of an entity like a vehicle, human or robot, and goal approaching, i.e., guiding this entity from one place to another. As specific to multi-agent navigation, collaboration among agents enhances the navigation capability by cooperative positioning and formation optimization [1], [2]. Eventually, for multi-agent information seeking [3], [4], agents can proactively adapt their formation, so that the positioning uncertainty is actively minimized while approaching a goal.