The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 23, 1982
Filed:
Oct. 03, 1980
Dave Hoff, Brooklyn Park, MN (US);
Honeywell, Inc., Minneapolis, MN (US);
Abstract
An apparatus for determining the time of the closest point of approach of a taxiing aircraft comprising a microphone means for producing an input signal in response to the sound energy of a taxiing jet. A low pass filter is provided to receive the input signal and pass low signals having a frequency less than or equal to 1 KHZ while a high pass filter is provided to receive the input signal and pass high signals having a frequency greater than or equal to 1.5 KHZ. Demodulators are provided for receiving the signals from both the high and low pass filters, and are adapted to produce a low frequency envelope from the low signal and a high frequency envelope from the high signal. Finally, comparator apparatus is provided for receiving the low frequency envelope and the high frequency envelope and comparing the amplitudes so as to provide a signal at the point in time when the amplitude of the low frequency envelope exceeds the amplitude of the high frequency envelope. This signal indicates in real time the point of closest approach of a taxiing jet aircraft.