Hybrid Electric-Field Sensor

The hybrid electric-field sensor (HEFS) has been proposed for measuring quasi-static electric fields — especially those associated with thunderstorms. The HEFS would combine the relative compactness, low cost, and low power consumption of prior inductionprobe- type electric-field sensors with the higher sensitivity of the prior fieldmill- type electric-field sensors. The HEFS design would utilize a choppingelectrostatic- shield feature of a field mill over two insulated antennas to overcome the finite time constant and the poor upper frequency response of the induction probe and the electric field mill, respectively. The HEFS would be modular in order to accommodate “smart” data-acquisition and communication ports for operation as a battery-powered, stand-alone unit. Optionally, the HEFS could incorporate a barometer, thermometer, and hygrometer, so that it could serve as a portable meteorological station. A network of such stations could transmit digitized measurement data to a central monitoring station. The estimated cost of an HEFS, including communication circuitry, is $1,000 (based on prices as of year 2001). In contrast, a field mill costs about $10,000. Moreover, unlike a field mill, an HEFS would consume little enough power that it could be powered by a solar power system backed by rechargeable batteries.