US 8,570,210 B1 · Aircraft MIMO radar

Abstract

Traditional airborne radar antennas are typically limited to placement above or below the aircraft, or in one or both of the wings, or in the nose. In the both-wing case, the fuselage prevents coherent array processing of both wing arrays without the introduction of grating lobes. Both wing arrays are coherently combined without grating lobes through appropriate geometric configurations of the arrays and the use of MIMO processing techniques. A virtual array is formed by convolving the transmit and receive apertures to fill in the gap created by the fuselage, thereby allowing fully coherent array processing and greater angular resolution than previously achievable through a conformal array. The signal-to-noise ratios are potentially improved.

Claims20

Dependent claims

A radar system, comprising:

first and second line arrays of receive antennas separated by a gap between an inside edge of the first line array and an inside edge of the second line array;
first and second antenna point sources transmitting signal waveforms;
wherein the first and second line arrays of receive antennas receive radar return signals originating with said first and second antenna point sources;
and
a digital processor utilizing multiple-input multiple-output (MNO) techniques for cohering said first and second line arrays of receive antennas to form a virtual array that extends across said gap.

2 more elements

A method for remote sensing,

comprising the steps of:
transmitting signal waveforms from first and second antenna point sources;
receiving radar return signals originating with said point sources with first and second line arrays of receive antennas separated by a gap between an inside edge of the first line array and an inside edge of the second line array;
and
digitally processing said radar return signals for cohering said first and second line arrays of receive antennas to form a virtual array that extends across said gap.

2 more elements

A radar system, said radar system comprising:

a first antenna array extending along a line, and having a first extent, at least in a horizontal plane;
a second antenna array extending along said line, and having an extent, which need not be the same as said first extent;
third and fourth antennas, said third antenna lying in a vertical plane passing through an inside end of said first array, and said fourth antenna lying in a vertical plane passing through an inside end of said second array, said third and fourth antennas lying at the same distance from said horizontal plane;
first and second transmitters for generating mutually orthogonal RF signals, said first and second transmitters being connected to said third and fourth antennas, respectively, for transmitting both first and second mutually orthogonal electromagnetic signals from each of said third and fourth antennas;
first and second receiver arrays coupled to said first and second antenna arrays and to said first and second transmitters, for processing reflected signals for generating first and second received signals from each of the elements of said first and second antenna arrays, respectively, each of said first and second received signals including first and second components of mutually orthogonal received signals attributable to said first and second mutually orthogonal electromagnetic signals;
first and second processors coupled to said first and second receiver arrays, respectively, and to said first and second transmitters, for processing said first and second received signals to separate said first and second components of said mutually orthogonal received signals;
and
a beamforming processor coupled to said first and second processors for coherently combining said first components of said mutually orthogonal received signals with said second components of said mutually orthogonal received signals to thereby define at least a first beam.

5 more elements

A radar system, said radar system comprising:

a first antenna array extending along a line, and having a length, at least in a horizontal plane;
a second antenna array extending along said line, and having said length, said second array being separated from said first array by a distance no greater than said
length, thereby defining an inside end and an outside end of each of said first and second arrays;
third and fourth antennas, said third antenna lying in a vertical plane passing through said inside end of said first array, and said fourth antenna lying in a vertical plane passing through said inside end of said second array, said third and fourth antennas lying at the same distance from said horizontal plane;
first and second transmitters for generating mutually orthogonal RF signals, said first and second transmitters being connected to said third and fourth antennas, respectively, for transmitting first and second mutually orthogonal electromagnetic signals from said third and fourth antennas, respectively;
first and second receiver arrays coupled to said first and second antenna arrays, for processing reflected signals for generating first and second received signals from each of said first and second antenna arrays, respectively, each of said first and second received signals including first and second components of mutually orthogonal received signals attributable to said first and second mutually orthogonal electromagnetic signals;
first and second processor arrays coupled to said first and second receiver arrays, respectively, for processing said first and second received signals to separate said first and second components of said mutually orthogonal received signals;
a second processor coupled to said first and second processor arrays for coherently combining said first components of said mutually orthogonal received signals with said second components of said mutually orthogonal received signals to thereby define a first beam.

5 more elements

Dependencies are inferred from the claim text.

Aircraft MIMO radar

Life of this patent

Aircraft MIMO radar

Life of this patent

Abstract

Claims20