Active sensor networks for nuclear detection

This paper approaches from an optimal control perspective the problem of fixed-time detection of mobile radioactive sources in transit by means of a collection of mobile sensors. Under simplifying assumptions on the geometry of the source, sensors, and surrounding environment, and with knowledge of the source´s trajectory, it is shown that the optimal control problem admits an intuitive, analytic closed-form solution. This is facilitated by the availability of analytic expressions for bounds on the probabilities of detection and false alarm during a Neyman-Pearson detection test. The intuition derived from this analytic solution leads to a motion control law that steers suboptimally the sensors to an arbitrarily small neighborhood of the suspected source, while navigating among stationary obstacles in their environment, making a step closer to a practical physical implementation.