Airborne wind shear response system
AssigneeR & D Associates
InventorDemos T. Kyrazis
Life of this patent
Estimating the term…
Abstract
An aircraft is provided with wind velocity measuring equipment which measures the wind velocity both (1) close to the aircraft and (2) at a considerable distance such as one-half mile or a mile away from the aircraft; and a large difference in these two measured velocities indicates dangerous windshear conditions. Either a warning signal is given to the pilot, or automatic control apparatus is actuated, to avoid crash conditions. A single pulsed carbon dioxide (CO.sub.2) laser velocimeter may be mounted in the aircraft for measuring both the close-in and the distant wind speeds. The laser optic focus is shifted between the near and far measurements, and the return signal is time gated to increase signal-to-noise ratio.
Claims9
An airborne wind shear safety system for mounting on an aircraft comprising:
- a laser;
- means for mounting said laser on an aircraft, with the laser directed substantially forwardly from the aircraft;
- means for focusing said laser alternately at a near zone close to the aircraft, and at a distant zone spaced at least one-quarter mile ahead of the aircraft;
- means for receiving the reflected return from aerosols or other particles in the air and for beating them with reference signals derived from said laser to provide a radio frequency signal representative of the doppler shift in the reflected signals at both the near zone and at the distant zone;
- means for determining the relative speed of the air with respect to the aircraft both at the near and distant zones from said radio frequency signals;
- means for determining the difference in relative speeds at the near and distant zones;
- a response circuit for initiating action to avoid air craft stall;
- and
- means for energizing said response circuit when said difference exceeds a predetermined level;
- whereby wind shear is detected at least several seconds prior to a drastic change in airspeed so that appropriate corrective action may be taken.
An airborne wind shear safety system for mounting on an aircraft comprising:
- a laser;
- means for mounting said laser on an aircraft, with the laser directed substantially forwardly from the aircraft;
- means for focusing said laser alternately at a near zone close to the aircraft, and at a distant zone spaced at least one-quarter mile ahead of the aircraft;
- means for receiving the reflected return from aerosols or other particles in the air and for beating them with reference signals derived from said laser to provide a radio frequency signal representative of the dopplar shift in the reflected signals at both the near zone and at the distant zone;
- means for determining the relative speed of the air with respect to the aircraft both at the near and distant zones from said radio frequency signals;
- means for determining the difference in relative speeds at the near and distant zones;
- a response circuit for initiating action to avoid aircraft stall;
- means for energizing said response circuit when said difference exceeds a predetermined level;
- and
- said system including means for providing a series of high power very short laser pulses for said distant velocity measurements, means for providing a long lower power pulse for said near velocity measurements, and means for maintaining said laser at very low power levels between pulses for reference frequency purposes;
- whereby wind shear is detected at least several seconds prior to a drastic change in airspeed so that appropriate corrective action may be taken.
An airborne wind shear safety system for mounting on an aircraft comprising:
- a laser;
- means for mounting said laser on an aircraft, with the laser directed substantially forwardly from the aircraft;
- means for focusing said laser alternately at a near zone close to the aircraft, and at a distant zone spaced at least one-quarter mile ahead of the aircraft;
- means for receiving the reflected return from aerosols or other particles in the air and for beating them with reference signals derived from said laser to provide a radio frequency signal representative of the doppler shift in the reflected signals at both the near zone and at the distant zone;
- means for determining the relative speed of the air with respect to the aircraft both at the near and distant zones from said radio frequency signals;
- means for determining the difference in relative speeds at the near and distant zones;
- a response circuit for initiating action to avoid aircraft stall;
- means for energizing said response circuit when said difference exceeds a predetermined level;
- and
- said speed determining means including an analog to digital converter, a fast fourier transform processor, and a microprocessor, for performing the velocity calculations;
- whereby wind shear is detected at least several seconds prior to a drastic change in airspeed so that appropriate corrective action may be taken.
Dependencies are inferred from the claim text.