Hyperbolic Positioning Using RIPS Measurements for Wireless Sensor Networks

Measurements based on a Radio Interferometric Positioning System (RIPS) can determine distance differences between pairs of motes in a wireless sensor network. Such measurements allow one to localise motes in the network when the locations of at least three motes are known. In the 2-dimensional case, a RIPS trilateration approach, which we describe in this paper, appears to be the most efficient way of localising all motes with respect to a set of known anchors. An important issue associated with this method is the sensitivity of the trilateration to RIPS measurement noise. In this paper we present an analytic study of the impact of RIPS measurement noise on the localisation error, the results of which can be used as a guide for choosing RIPS measurements that minimise the localisation error. A simulated example demonstrates the underlying idea, and its effectiveness.