Aerial drone for radar calibration

Patent metadata

Field	Value
Publication number	US-10705187-B1
Application number	US-201715598352-A
Country	US
Kind code	B1
Filing date	May 18, 2017
Priority date	May 18, 2017
Publication date	Jul 7, 2020
Grant date	Jul 7, 2020

Abstract

An aerial drone or unmanned aerial vehicle (UAV) is provided for radar calibration testing. The drone includes an airframe including a fuselage with nose and tail, wings and elevators. The drone includes at least one antenna attached to the airframe, as well as a signal adapter coupled to the antenna to receive impinging radar signals and transmit an electromagnetic (EM) field that effectively cancels or combines with the scattered field of the drone, depending upon the adapter's mode of operation. In the first mode of operation, the adapter transmits an EM field that has an opposite phase to the drone's scattered field thereby reducing the radar cross-section of the drone. In the second mode, the adapter transmits an EM field that is in-phase with the scattered field thereby increasing the radar cross-section of the drone.

First claim

What is claimed is:

1. An aerial drone for radar cross-section (RCS) signal response calibration of a radar that transmits an emission signal, said drone reflecting a return signal dependent on an RCS and comprising:
an airframe fuselage with port and starboard profiles along a longitudinal axis;
port and starboard wings disposed laterally to said longitudinal axis corresponding to said respective profiles;
a corner reflector on said fuselage along one of said port and starboard profiles for amplifying the return signal to increase the RCS; and
an energy absorber on said fuselage along the other of said port and starboard profiles for attenuating the return signal to decrease the RCS.

2. The drone according to claim 1 , wherein said corner reflector denotes a plurality of corner reflectors disposed along said fuselage, and said energy absorber denotes a plurality of energy absorbers disposed along said fuselage.

3. The drone according to claim 1 , further comprising a blade antenna to receive the emission signal from the radar and transmit the return signal.

4. The drone according to claim 3 , wherein said blade antenna is a plurality of blade antennas longitudinally disposed along said fuselage.

5. The drone according to claim 1 , wherein said fuselage includes opposing bilateral first and second surfaces along said longitudinal axis, said first surface exhibiting a first RCS profile and said second surface exhibiting a second RCS profile that is relatively larger than said first RCS profile.

6. The drone according to claim 5 , wherein said first surface incorporates a radar absorbing material that reduces the RCS.

7. The drone according to claim 5 , further including a passive corner reflector disposed on said second surface that increases the RCS.

8. The drone according to claim 7 , further including a shutter positioned adjacent to said passive corner reflector, said shutter being configurable to open and closed positions, wherein the emission signal is
reflected by said passive corner reflector so to enhance the RCS on said second side for said shutter being in said open position, and
obscured from said passive corner reflector for said shutter being in said closed position.

9. The drone according to claim 1 , further including:
a flight controller for directing the drone;
a GPS receiver for instructing said flight control; and
an inertial navigation system in electronic signal communication with said GPS receiver.

10. The drone according to claim 9 , wherein said flight controller flies the drone around the radar in an anti-clockwise path to present said port profile.

11. The drone according to claim 9 , wherein said flight controller flies the drone around the radar in a clockwise path to present said starboard profile.

Assignees

• Hebert James L
• Us Navy

Inventors

• Hebert James L

Classifications

• G01S7/4082

  using externally generated reference signals, e.g. via remote reflector or transponder · CPC title

• G01S7/4052

  by simulation of echoes · CPC title

• F41J9/08

  Airborne targets, e.g. drones, kites, balloons {(aircraft for towing targets B64D3/02)} · CPC title

• F41J2/00 Primary

  Reflecting targets, e.g. radar-reflector targets; Active targets transmitting electromagnetic {or acoustic} waves · CPC title

• G01S7/414

  Discriminating targets with respect to background clutter · CPC title