Hyo K Chung

US Patent:

7456788, Nov 25, 2008

Filed:

Dec 22, 2005

Appl. No.:

11/316299

Inventors:

Hyo K. Chung - Greenville TX, US
David L. Reid - Richardson TX, US

Assignee:

L-3 Communications Integrated Systems L.P. - Greenville TX

International Classification:

G01S 3/02

US Classification:

342451, 342453

Abstract:

A method and apparatus for reducing geolocation ambiguity in signal tracking. The method and apparatus generally include acquiring a first and a second set of geolocations and comparing the sets to reduce ambiguous geolocations. Such a configuration enables accurate and rapid geolocation determination without requiring complex and time-consuming direction finding devices and methods.

US Patent:

7471245, Dec 30, 2008

Filed:

Jan 31, 2007

Appl. No.:

11/669734

Inventors:

Hyo K. Chung - Greenville TX, US
Phuong H. Le - Plano TX, US
John M. Parker - Sachse TX, US
David L. Reid - Richardson TX, US
Mark A. Robertson - Greenville TX, US

Assignee:

L3 Communications Integrated Systems, L.P. - Greenville TX

International Classification:

G01S 3/02

US Classification:

342465, 342451

Abstract:

Methods and apparatus operable to estimate the geolocation of a signal emitter. In some embodiments, the methods comprise acquiring collection data from a plurality of collector elements, computing a plurality of candidate geolocations from the acquired collection data, and applying a clustering analysis to the candidate geolocations to estimate the geolocation of the signal emitter.

US Patent:

7489937, Feb 10, 2009

Filed:

Dec 22, 2005

Appl. No.:

11/316297

Inventors:

Hyo K. Chung - Greenville TX, US
David L. Reid - Richardson TX, US

Assignee:

L-3 Communications Integrated Systems, L.P. - Greenville TX

International Classification:

H04Q 7/20

US Classification:

4554561, 342 84

Abstract:

A method and apparatus for detecting emitter movement. The method and apparatus generally include acquiring a measured signal characteristic corresponding to a signal emitted from an emitter, estimating a signal characteristic corresponding to the signal, and comparing the measured and estimated signal characteristics to determine if the emitter is moving. Such a configuration enables a rapid and accurate detection of emitter movement without requiring multiple measurements, complex systems, or time-consuming calculations.

US Patent:

7626546, Dec 1, 2009

Filed:

Sep 27, 2007

Appl. No.:

11/904630

Inventors:

Hyo K. Chung - Greenville TX, US
Phuong H. Le - Plano TX, US
John M. Parker - Sachse TX, US
David L. Reid - Richardson TX, US
Mark A. Robertson - Greenville TX, US

Assignee:

L-3 Communications Integrated Systems L.P. - Greenville TX

International Classification:

G01S 3/02

US Classification:

342465

Abstract:

Systems and methods for detection and geolocation of multiple emitters that are emitting RF signal energy on a common frequency, and that may be implemented to separate, geolocate, and/or determine the number of emitters (e. g. , radio users) emitting on a common RF frequency. Real-time signal qualification processing may be employed to continuously monitor and collect incoming receiver tuner data for signal activity and ignore irrelevant noise data. Each set of data blocks from an emitter transmission signal may be defined as an emission cluster, and a set of time difference of arrival (TDOA)/frequency difference of arrival (FDOA) pairs may be computed for each emission cluster with each TDOA/FDOA pair yielding a geolocation result. A statistical qualification method may be used to produce a final geolocation answer from each set of emission cluster geolocation results, and a geolocation error ellipse computed for the final geolocation answer of each emission cluster. The final geolocation answer of each emission cluster may be run through a correlation and fusion algorithm.

US Patent:

7664512, Feb 16, 2010

Filed:

Aug 10, 2006

Appl. No.:

11/463804

Inventors:

Hyo K Chung - Greenville TX, US
Phuong H Le - Plano TX, US
John M Parker - Sachse TX, US
David L Reid - Richardson TX, US
Mark A Robertson - Greenville TX, US

Assignee:

L3 Communications Integrated Systems, L.P. - Greenville TX

International Classification:

H04W 24/00

US Classification:

4554561, 455 121, 375350, 34235701, 34235709

Abstract:

A geolocation system () includes an emitter (), a plurality of collection nodes (), and a control station (). Each collection node includes a receiver () that is operable to receive signals transmitted from the emitter (), generate a reduced data stream that includes only signal data, and communicate the reduced data stream to the control station () along with navigation data. The receiver () identifies signal data by detecting an energy level of the raw collection data. More specifically, the receiver () determines a bandwidth and a signal-to-noise ratio of each portion of the collection data, and identifies each portion as including signal data if both the bandwidth and the signal-to-noise ratio exceed predetermined threshold amounts. The receiver () includes a digital signal processing component () for performing calculations used by the receiver () to determine the bandwidth and the signal-to-noise ratio.