Patents by Inventor Michel B. Andrieu

Michel B. Andrieu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Process and device for passive detection of aircraft, namely helicopters
    Patent number: 4719606
    Abstract: A process and device for passive detection of helicopters includes detection of helicopter noise and ambient noise by means of an electro-acoustic transducer, and outputting of an amplitude modulated signal therefrom; amplitude demodulation of the signal in the frequency band between 300 Hz and 3500 Hz; spectral analysis of the demodulated signal; and selection and registration of characteristic frequency lines reflective of the rotary units of the helicopter. The process and device permit passive detection of helicopters in the lower noise, higher frequency band, thereby also permitting utilization of smaller antenna arrays.
    Type: Grant
    Filed: March 14, 1985
    Date of Patent: January 12, 1988
    Assignee: Etat Francais
    Inventor: Michel B. Andrieu