skip to main content

Title: Narrow field electromagnetic sensor system and method

A narrow field electromagnetic sensor system and method of sensing a characteristic of an object provide the capability to realize a characteristic of an object such as density, thickness, or presence, for any desired coordinate position on the object. One application is imaging. The sensor can also be used as an obstruction detector or an electronic trip wire with a narrow field without the disadvantages of impaired performance when exposed to dirt, snow, rain, or sunlight. The sensor employs a transmitter for transmitting a sequence of electromagnetic signals in response to a transmit timing signal, a receiver for sampling only the initial direct RF path of the electromagnetic signal while excluding all other electromagnetic signals in response to a receive timing signal, and a signal processor for processing the sampled direct RF path electromagnetic signal and providing an indication of the characteristic of an object. Usually, the electromagnetic signal is a short RF burst and the obstruction must provide a substantially complete eclipse of the direct RF path. By employing time-of-flight techniques, a timing circuit controls the receiver to sample only the initial direct RF path of the electromagnetic signal while not sampling indirect path electromagnetic signals. The sensor systemmore » also incorporates circuitry for ultra-wideband spread spectrum operation that reduces interference to and from other RF services while allowing co-location of multiple electronic sensors without the need for frequency assignments. 12 figs.« less
Authors:
Publication Date:
OSTI Identifier:
403667
Report Number(s):
US 5,576,627/A/
PAN: US patent application 8-405,644; TRN: 97:000142
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Patent
Resource Relation:
Other Information: PBD: 19 Nov 1996
Research Org:
University of California
Country of Publication:
United States
Language:
English
Subject:
05 NUCLEAR FUELS; 44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; INTRUSION DETECTION SYSTEMS; DESIGN; RADIOWAVE RADIATION; RADIATION DETECTION; RADIATION MONITORS; USES; DATA PROCESSING; TIME-OF-FLIGHT METHOD; MEASURING METHODS