I. Introduction
An important consideration for tracking a target in a sensor network is the natural trade-off between the cost of sensing resources and the quality of tracking performance [1], [2]. As more sensors are allocated, the tracking quality tends to improve, albeit at an increased sensor-usage cost. For networks where energy is a valuable resource, it is necessary to minimize the network energy consumption subject to constraints on tracking accuracy. Sensor scheduling, a process to allocate future sensing resources by optimizing a scheduler cost under constraints, is a natural solution to such problems.