Demonstration of a Network of Simultaneously Operating Digital Noise Radars [Measurements Corner]

Search and rescue following a natural disaster is a difficult problem, exacerbated by the cluttered environment obscuring human victims. It is well known that UHF radar-frequency radiation can penetrate the types of materials typically found in these situations with relatively little loss. This paper discusses the development of a network of digital noise radars, designed to operate in that frequency range to locate and track human movement through walls and rubble. Each individual noise radar works by cross correlating the received signal with a replica of the transmit signal. A high correlation indicates the range to the target. This noise radar design makes use of the software radar concept by converting the analog transmitted and received signals to digital signals. With the signals in digital form, the cross-correlation process can be accomplished in software. A network of three digital noise radars was developed. The three radars operated simultaneously in the same frequency range, without interference, to triangulate the (x, y) position of a target within a room. The results showed that the network of radars was capable of locating and tracking a human through an obscuring wall.