Planning Aims for a Network of Horizontal and Overhead Sensors

This paper considers the problem of planning sensor observations for a network of overhead sensors which will resolve ambiguities in the output of a horizontal sensor network. Specifically, we address the problem of counting the number of objects detected by the horizontal sensor network, using the overhead network to aim at specific areas to improve the count. The main theme of our results is that, even though observation planning is intractable for such a network, a simple, greedy algorithm for controlling the overhead sensors guarantees performance with bounded and reasonable suboptimality. Our results are general and make few assumptions about the specific sensors used. The techniques described in this paper can be used to plan sensor aims for a wide variety of sensor types and counting problems.