|국가/구분||United States(US) Patent 등록|
|미국특허분류(USC)||343/6ND ; 343/5HE ; 250/342|
|발명자 / 주소|
|출원인 / 주소|
|인용정보||피인용 횟수 : 16 인용 특허 : 6|
A device for the detection of and defense against low-flying helicopters which are masked or hidden by ground cover has a heat-sensitive sensor and an optical filter to detect heat radiation which is modulated at a frequency corresponding to the frequency of rotation of the helicopter blades. The helicopter motor and drive train provide a heat source, and the detector is positioned above the helicopter so that heat radiation reaching the detector from the helicopter is modulated by the rotating blades so that the detector can distinguish the helicopter h...
A system for detection of and defense against low-flying helicopters, having a drive means and rotary lifting blades operating at an angular frequency and disposed above said drive means, which are hidden by ground cover, said system comprising: a detector for detecting thermal radiation produced by said drive means and generating an electric signal upon such detection; a band pass optical filter disposed between said detector and said blades of said helicopter for admitting only thermal radiation to said detector having a temperature corresponding to th...