A sensor array that forms part of an intrusion detection system, which is adapted for use on narrow spaced objects that surround a perimeter. The sensor array includes at least two intrusion detection sensor nodes, a plurality of node processors corresponding to each sensor node, and a deformable cable. The plurality of sensor nodes are situated and spaced along the deformable cable. The at least two sensory nodes include one or more discrete volumetric sensors with associated volumetric detection fields extending from each discrete volumetric sensor. Each sensor node has a detection zone extending transversely to the longitudinal direction of the deformable cable at the sensor node and defined by the detection fields of its constituent sensors as constructed and arranged in each sensor node. Each sensor node includes a node processor situated thereat for processing a response generated by the sensors when an intruder enters a nodes detection zone. An array processor of the sensor array can be coupled to each node processor to receive and process alarm disturbance signatures from each node processor.