Date Added: Nov 2009
A critical problem in mobile ad-hoc wireless sensor networks is each node's awareness of its position relative to the network. This problem is known as localization. In this paper, the authors introduce a variant of this problem, directional localization, where each node must be aware of both its position and orientation relative to its neighbors. Directional localization is relevant for applications that require uniform area coverage and coherent movement. Using global positioning systems for localization in large scale sensor networks may be impractical in enclosed spaces, and might not be cost effective. In addition, a set of pre-existing anchors with globally known positions may not always be available.