Abstract: A mobile emergency perimeter system includes one or more fixed radio frequency (RF) sensors, and one or more moving RF sensors; a wireless mesh network coupling together each of the sensors; and a central processor system coupled to the wireless mesh network. The central processor system executes machine instructions stored on a computer-readable storage medium to control each of the RF sensors to receive time of arrival data for a RF signal transmitted by an emitter and received at each of the RF sensors, receive location information for each of the RF sensors and determine a three-dimensional (3-D) estimate of the geographical location of the emitter.