The emerging technology of Wireless Sensor Networks offers the potential for a new and unparalleled level of surveillance for events occurring in an environment. The quality of surveillance will be directly related to the quantity and density of sensors that can be deployed, and that are actively participating in the monitoring at any given instant. In opposition to this is the requirement for judicious power management of the network in order to prolong its operational lifespan by minimizing node activity. In this paper we explore the effect on surveillance quality when using interpolation error as a mechanism for deciding node activations. More specifically we examine the effect of using this signal based hibernation technique on target localization error and node activity.