Location Estimation of Isotropic Transmitters in Wireless Sensor Networks

There are several techniques available for determining the location of wireless transmitters in a network of receivers. The simplest technique for use in sensor networks, is to interpolate the position of the transmitter in the network using the received signal strength (RSS). In this paper we review the RSS geometric locating process. We consider the model for the propagation path to determine an optimal estimate of the location of an isotropic transmitter. We apply a location estimation algorithm to experimental data taken in the field. The experiments involved locating GSM cellular transmitters within a network of power sensors which we emulated with GSM handsets. We analyze the performance of the algorithm in light of the the field tests. We consider modifications of the model to encompass the more nuanced nature of real directional transmitters. We conclude with some remarks on applications of this process to intrusion detection and locating mobile users for emergency services