Kai Bor Yu

US Patent:

6531976, Mar 11, 2003

Filed:

Sep 7, 2001

Appl. No.:

09/948959

Inventors:

Kai Bor Yu - Niskayuna NY

Assignee:

Lockheed Martin Corporation

International Classification:

G01S 736

US Classification:

342 16, 342 13, 342 74, 342 81, 342128, 342130, 342131, 342132, 342195, 342196

Abstract:

A wideband adaptive digital beamforming technique for maintaining a high range resolution profile of a target in motion in the presence of jamming utilizes a sequence of adaptively calculated narrowband jamming cancellation weights. The adaptive weights are calculated such that the desired frequency dependent gain is maintained toward the target center. These adaptive weights tend to preserve the range profile quality and low range sidelobes. This technique also tends to eliminate signal cancellation problems as well as adaptive weight modulation effects.

US Patent:

6580392, Jun 17, 2003

Filed:

Sep 7, 2001

Appl. No.:

09/949170

Inventors:

Kai Bor Yu - Niskayuna NY

Assignee:

Lockheed Martin Corporation

International Classification:

G01S 302

US Classification:

342378, 342 17, 342450, 342453, 342417, 367119

Abstract:

A radar system and method for detecting and tracking a target of interest in the presence of interference, wherein the interference emits interfering signals, includes a receiver for receiving the interfering signals directly from the interference. The receiver also receives reflected signals, wherein the reflected signals is the interfering signals reflected by the target of interest. The interfering signals and the reflected signals are compared to detect the target of interest. In one embodiment, the reflected signals and the interfering are cross-correlated. The results of the cross-correlation are used to obtain range, position, and velocity information about the target of interest from a range/Doppler map.

US Patent:

6697009, Feb 24, 2004

Filed:

Jul 3, 2002

Appl. No.:

10/189337

Inventors:

Kai Bor Yu - Niskayuna NY

Assignee:

Lockheed Martin Corporation

International Classification:

G01S 736

US Classification:

342 17, 342 13, 342 16, 342 74, 342 75, 342 80, 342149, 342159, 342175, 342195

Abstract:

A system and method for detecting a radar target of interest in the presence of radar jamming interference include a sub-array beamformer, a sum and difference beamformer, a weight calculator, a composite beamformer, and a monopulse ratio calculator. A plurality of sub-arrays is formed from antenna array element data. Respective sum and difference beams are formed for each of the plurality of sub-arrays. A single weight is formulated from the sum and difference beams, respectively. Composite sum beams are formed in accordance with the sum weights and the sum beams, and composite difference beams are formed in accordance with the difference weights and the difference beams. Composite beams are formed such that at least one null of each of the composite beams is steered toward an interference and a boresight gain of each of the composite beams is maintained.

US Patent:

7576682, Aug 18, 2009

Filed:

Mar 14, 2006

Appl. No.:

11/375460

Inventors:

Kai Bor Yu - Niskayuna NY, US

Assignee:

Lockheed Martin Corporation - Bethesda MD

International Classification:

G01S 13/06

US Classification:

342 90, 342 16, 342147

Abstract:

A method for radar target detection and angle estimation in the presence of jamming includes the steps of receiving a signal from a radar array having elements arranged in rows and columns; performing deterministic row-based beamforming on the received signal to obtain row sum azimuth beams; performing deterministic column-based beamforming on the received signal to obtain column sum elevation beams; performing one-dimensional maximum likelihood estimation on the row sum azimuth beams to obtain an estimated target elevation angle and an adaptive array sum azimuth beam; performing one-dimensional maximum likelihood estimation on the column sum elevation beams to obtain an estimated target azimuth angle and an adaptive array sum elevation beam; and performing target detection based on the adaptive array sum azimuth beam and the adaptive array sum elevation beam.

US Patent:

20030184473, Oct 2, 2003

Filed:

Mar 27, 2002

Appl. No.:

10/107977

Inventors:

Kai Yu - Niskayuna NY, US

International Classification:

G01S003/16

US Classification:

342/380000

Abstract:

A radar system and technique provide the capability to detect a target of interest and maintain the detection in the presence of multiple mainlobe and sidelobe jamming interference. The system and technique utilize the versatility of digital beamforming to form sub-arrays for canceling jamming interference. Jamming is adaptively suppressed in the sub-arrays prior to using conventional deterministic methods to form the sum, , and difference, , beams for monopulse processing. The system and technique provide the ability to detect a target of interest, provide an undistorted monopulse ratio, m, and maintain target angle estimation, in the presence of multiple mainlobe and multiple sidelobe jammers. Further, this system and technique are not constrained by requiring a priori knowledge of the jamming interference.