Distributed electrical field sensors

A distributed sensing, tracking and imaging network where each constituent element or node consists of (i) sensing means, specifically one or more electrodes that emit a controllable, alternating current ("AC") electric field ("E-field"), together with one or more electrodes configured to detect and measure displacement current or voltage induced on conductors in proximity to the sensor, (ii) wireless communication means linking multiple sensors with each other and with a central processor as part of an extensible, distributed array, (iii) processing means, both "on-sensor" and at a centralized processing location, including (a) optimized communication protocols, (b) algorithms to estimate the size/shape/orientation of electrically isolated and/or connected conductors by exploiting multi-static measurements to infer the surface charge distribution induced on the conductor by the active AC electric field (and hence the three dimensional characteristics of object), (c) algorithms for the adaptive control and management of a distributed electric field tomography system, including ability to control emission waveform, frequency, power and other characteristics, task other nodes for multi-static operation that optimizes performance in different operating modes, and adaptively change operating modes, (d) algorithms to enable the relative geo-location, calibration and scaling of a network of cooperative E-field sensors, and (e) algorithms to exploit portable netted E-field sensor mobility, AC field frequency agility and various emission coding schemes to create angular diversity for image formation, disambiguate the reconstructed surface characteristics of conductors of interest, and to enable multi-static operation and extend useful operating range and (iv) visualization means to solve the inverse problem and provide a real time reconstructed two dimensional representation.

Patent #: 7330032 Issue Date: June 10, 2008