Charles H Hansen

US Patent:

6987479, Jan 17, 2006

Filed:

Aug 17, 2004

Appl. No.:

10/919733

Inventors:

Charles T. Hansen - Palos Verdes Estates CA, US
Michael E. Lawrence - San Pedro CA, US

Assignee:

Raytheon Company - Waltham MA

International Classification:

G01S 13/90

US Classification:

342 25F, 342 25 R, 342 25 A, 342175, 342176, 342179, 342190, 342191, 342195, 342196

Abstract:

Motion compensation for coherent combination of pulses facilitates a SAR image of a scene on earth's surface. A great circle () is centered with respect to the earth's center, The great circle () has an axis () perpendicular to a first plane. Axis () passes through the earth's center. The first plane contains great circle () and includes the earth's center. Great circle () has a first center defined by an intersection of the first plane and axis (). The scene has one or more radar scatterers and is located on a surface (). The radar system is mounted on a moving platform () moving with a component of motion in a direction along great circle (). The radar comprises a radar receiver for digitizing the radar returns having a phase from scatterers on surface (), and a computer for focusing the phase of said radar returns from the scatterers on surface (). The surface () is located on a local scene centerline circle (), the local scene centerline circle () defining a second plane. This second plane is parallel to the first plane.

US Patent:

7126524, Oct 24, 2006

Filed:

Aug 4, 2004

Appl. No.:

10/911438

Inventors:

Charles T. Hansen - Palos Verdes Estates CA, US
Michael E. Lawrence - San Pedro CA, US

Assignee:

Raytheon Company - Waltham MA

International Classification:

G01S 13/90

US Classification:

342 25A, 342 25 F

Abstract:

A synthetic aperture image of a scene is acquired using a radar system. The scene has one or more radar scatterers located on a horizontal flat {circumflex over (x)},ŷ plane. The radar system is mounted on a moving platform moving at an angle θwith respect to the {circumflex over (x)},ŷ plane, with a component of motion in a perpendicular {circumflex over (z)} direction. The synthetic aperture image acquisition requires digitizing radar returns having a phase returned from scatterers in the scene, adjusting the phase of the radar returns in response to θto generate phase adjusted returns, then computing the synthetic aperture image from said phase adjusted returns. The phase adjustment takes into account θplatform motion with respect to the scene.

US Patent:

7142149, Nov 28, 2006

Filed:

Oct 19, 2004

Appl. No.:

10/967956

Inventors:

Charles T. Hansen - Palos Verdes Estates CA, US

Assignee:

Raytheon Company - Waltham MA

International Classification:

G01S 13/90

US Classification:

342 25R, 342 25 A, 342 25 F

Abstract:

A radar system is mounted on a moving platform moving along a great circle. The radar comprises a radar receiver for digitizing radar returns having a phase from a scatterer (target) in a scene. A computer focuses the phase of the radar returns from the scatterer in the scene, using cylindrical coordinates to arrive at an image. An initial position estimate of the scatterer (target) within the image is made. This initial position is converted from cylindrical coordinates to geodesic coordinates of initial latitude, initial longitude and initial elevation. The geodesic coordinates are used to compare with a database descriptive of earth's surface. The initial elevation is replaced with that contained in the database. A second scatterer (target) location is computed using the database elevation. The second target location is compared with the first target location to obtain a difference.

US Patent:

8384588, Feb 26, 2013

Filed:

Oct 26, 2010

Appl. No.:

12/925668

Inventors:

Charles T. Hansen - Palos Verdes Estates CA, US

Assignee:

Raytheon Company - Waltham MA

International Classification:

G01S 13/44

US Classification:

342154, 342149, 342196

Abstract:

A method for estimating a target angle of a wideband signal received on an electronically steered antenna array includes: generating spatial frequency data from the received wideband signal; stabilizing the spatial frequency data to a beam steering direction; compressing the stabilized spatial frequency data to a plurality of frequency range bins; calculating a monopulse discriminant from the stabilized spatial frequency data; and calculating the target angle using the monopulse discriminant.

US Patent:

8451173, May 28, 2013

Filed:

Apr 21, 2011

Appl. No.:

13/092073

Inventors:

Charles T. Hansen - Palos Verdes Estates CA, US

Assignee:

Raytheon Company - Waltham MA

International Classification:

G01S 5/02

US Classification:

342422

Abstract:

A method for estimating a target direction of a wideband signal received on an electronically steered array includes: applying convolutional or stretch processing to spatial frequency data of the wideband signal; initializing a stabilization direction to a beam pointing direction; stabilizing the spatial frequency data to the stabilization direction; compressing the spatial frequency data to a plurality of frequency range or time bins; selecting range or time bins and forming a covariance matrix; calculating an estimated target direction using the covariance matrix; determining if a stabilization direction accuracy condition is met; recalculating the stabilization direction based on the estimated target direction if the stabilization direction accuracy condition is not met; and iteratively repeating until the stabilization direction accuracy condition is met.

US Patent:

20230087268, Mar 23, 2023

Filed:

Sep 21, 2021

Appl. No.:

17/448258

Inventors:

- Santa Clara CA, US
Seth Schneider - San Jose CA, US
Cody Robson - Portland OR, US
Lars Nordskog - Corte Madera CA, US
Charles Hansen - San Francisco CA, US
Rouslan Dimitrov - Santa Clara CA, US

International Classification:

G06T 1/20
G06F 9/48
G06F 9/38

Abstract:

A weighted average execution time associated with each execution stage of a plurality of execution stages used to process a plurality of frames in parallel is obtained. The processing of each of the plurality of frames is performed at each of the plurality of execution stages in a sequential order, starting with an initial execution stage and continuing with each subsequent execution stage. A first largest weighted average execution time associated with one of the plurality of execution stages is determined. A delay to the initial execution stage prior to processing a first next frame is applied. The delay is determined based on the first largest weighted average execution time.

US Patent:

20190280608, Sep 12, 2019

Filed:

May 16, 2019

Appl. No.:

16/413993

Inventors:

- Waltham MA, US
Charles Hansen - Palos Verdes Estates CA, US
Michael Brandon Kremer - Cambridge MA, US
Christopher Paul Vander Valk - West Chester OH, US
Joud Khoury - Boston MA, US

International Classification:

H02M 5/458
H04L 5/00
G01S 13/02
H04L 27/26
G01S 7/00
H04L 1/00
H03M 13/25
H04L 25/03
G01S 13/26
G01S 7/36
G01S 7/02

Abstract:

Generally discussed herein are systems, devices, and methods for generating multi-function waveforms. A device can include input circuitry to receive parameters indicating respective frequencies and codes for the multi-function waveforms, one or more memories to store the respective frequencies and codes, waveform management circuitry configured to produce a series of values based on the frequencies and codes, respectively, and refine the series of values by reducing a cost associated with a waveform produced using the series of values, and a transceiver to generate the waveform.

US Patent:

20190179007, Jun 13, 2019

Filed:

Dec 11, 2017

Appl. No.:

15/838053

Inventors:

- Waltham MA, US
Charles T. Hansen - Palos Verdes Estates CA, US

International Classification:

G01S 13/90

Abstract:

A system and method for forming synthetic aperture radar images. Radar return pulses are grouped into sub-dwells, and their frequency content is separated into frequency sub-bands. A coarse image is formed for each sub-band/sub-dwell combination. The coarse images are iteratively interpolated to higher resolution and combined, to form a single high-resolution synthetic aperture radar image.