Multi-target device-free tracking using radio frequency tomography

This paper examines device-free tracking of multiple targets based on radio-frequency received signal strength (RSS) measurements recorded by a sensor network. We report experimental results that validate, for relatively uncluttered outdoor environments, a recently proposed model in which targets cause additive attenuation. Using this model, we examine the performance of three multi-target tracking algorithms using a experimental sensor network testbed consisting of 24 nodes that conducts surveillance of an outdoor area of size 50m². The experiments are restricted to the case of a fixed number of targets (up to four). For four targets, all algorithms are able to track with average error less than 1m (as measured using the second-order OMAT metric); for two targets the error is close to 0.2m.