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Intrusion detection systems with turbulence discrimination

  • US 4,003,045 A
  • Filed: 10/01/1975
  • Issued: 01/11/1977
  • Est. Priority Date: 10/01/1975
  • Status: Expired due to Term
First Claim
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1. An intrusion alarm system for detecting the presence of a moving target in the presence of interfering signals, comprising:

  • a. means for transmitting signals into a zone under surveillance,b. means for receiving signals returned from said zone,c. processing means operative in response to said received signals to provide an output signal, indicative of said moving target and said interfering signal,d. first means for differentiating said output signal,e. second means for integrating said output signal,f. detector means coupled to said first and second means and responsive to said differentiated signal to store a magnitude proportional to said integrated signal during a predetermined periodg. threshold means coupled to said detector means and operative to provide an alarm signal when said stored magnitude is relatively constant during said predetermined period.

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