Bertice Lee Tise

US Patent:

6469661, Oct 22, 2002

Filed:

Jan 19, 2001

Appl. No.:

09/766322

Inventors:

Armin W. Doerry - Albuquerque NM
Bertice L. Tise - Albuquerque NM

Assignee:

Sandia Corporation - Albuquerque NM

International Classification:

G01S 7285

US Classification:

342194, 375349

Abstract:

A method of providing a balanced demodular output for a signal such as a Doppler radar having an analog pulsed input; includes adding a variable phase shift as a function of time to the input signal, applying the phase shifted input signal to a demodulator; and generating a baseband signal from the input signal. The baseband signal is low-pass filtered and converted to a digital output signal. By removing the variable phase shift from the digital output signal, a complex data output is formed that is representative of the output of a balanced demodulator.

US Patent:

6825800, Nov 30, 2004

Filed:

May 13, 2003

Appl. No.:

10/436728

Inventors:

Peter A. Dudley - Albuquerque NM
Armin W. Doerry - Albuquerque NM
Dale F. Dubbert - Cedar Crest NM
Bertice L. Tise - Albuquerque NM

Assignee:

Sandia Corporation - Albuquerque NM

International Classification:

G01S 735

US Classification:

342195, 342 25, 342194

Abstract:

Frequency dependent corrections are provided for quadrature imbalance. An operational procedure filters imbalance effects without prior calibration or equalization. Waveform generation can be adjusted/corrected in a synthetic aperture radar system (SAR), where a rolling phase shift is applied to the SARs QDWS signal where it is demodulated in a receiver; unwanted energies, such as imbalance energy, are separated from a desired signal in Doppler; the separated energy is filtered from the receiver leaving the desired signal; and the separated energy in the receiver is measured to determine the degree of imbalance that is represented by it. Calibration methods can also be implemented into synthesis. The degree of quadrature imbalance can be used to determine calibration values that can then be provided as compensation for frequency dependent errors in components, such as the QDWS and SSB mixer, affecting quadrature signal quality.

US Patent:

6828933, Dec 7, 2004

Filed:

May 13, 2003

Appl. No.:

10/436631

Inventors:

Armin W. Doerry - Albuquerque NM
Peter A. Dudley - Albuquerque NM
Dale F. Dubert - Cedar Crest NM
Bertice L. Tise - Albuquerque NM

Assignee:

Sandia Corporation - Albuquerque NM

International Classification:

G01S 735

US Classification:

342194, 342 25, 342195

Abstract:

Frequency dependent corrections are provided for quadrature imbalance and Local Oscillator (LO) feed-through. An operational procedure filters imbalance and LO feed-through effects without prior calibration or equalization. Waveform generation can be adjusted/corrected in a synthetic aperture radar system (SAR), where a rolling phase shift is applied to the SARs QDWS signal where it is demodulated in a receiver; unwanted energies, such as LO feed-through and/or imbalance energy, are separated from a desired signal in Doppler; the separated energy is filtered from the receiver leaving the desired signal; and the separated energy in the receiver is measured to determine the degree of imbalance that is represented by it. Calibration methods can also be implemented into synthesis. The degree of LO feed-through and imbalance can be used to determine calibration values that can then be provided as compensation for frequency dependent errors in components, such as the QDWS and SSB mixer, affecting quadrature signal quality.

US Patent:

6836240, Dec 28, 2004

Filed:

May 13, 2003

Appl. No.:

10/437329

Inventors:

Dale F. Dubbert - Cedar Crest NM
Peter A. Dudley - Albuquerque NM
Armin W. Doerry - Albuquerque NM
Bertice L. Tise - Albuquerque NM

Assignee:

Sandia Corporation - Albuquerque MN

International Classification:

G01S 735

US Classification:

342194, 342 25, 342195

Abstract:

Frequency dependent corrections are provided for Local Oscillator (LO) feed-through. An operational procedure filters LO feed-through effects without prior calibration or equalization. Waveform generation can be adjusted/corrected in a synthetic aperture radar system (SAR), where a rolling phase shift is applied to the SARs QDWS signal where it is demodulated in a receiver, unwanted energies, such as LO feed-through energy, are separated from a desired signal in Doppler; the separated energy is filtered from the receiver leaving the desired signal; and the separated energy in the receiver is measured to determine the degree of imbalance that is represented by it. Calibration methods can also be implemented into synthesis. The degree of LO feed-through can be used to determine calibration values that can then be provided as compensation for frequency dependent errors in components, such as the QDWS and SSB mixer, affecting quadrature signal quality.

US Patent:

6864827, Mar 8, 2005

Filed:

Oct 15, 2003

Appl. No.:

10/686379

Inventors:

Bertice L. Tise - Albuquerque NM, US
Dale F. Dubbert - Cedar Crest NM, US

Assignee:

Sandia Corporation - Albuquerque NM

International Classification:

G01S013/90

US Classification:

342 25A, 342 25 D, 342 25 F, 342194, 342195

Abstract:

A digital IF receiver (DRX) module directly compatible with advanced radar systems such as synthetic aperture radar (SAR) systems. The DRX can combine a 1 G-Sample/sec 8-bit ADC with high-speed digital signal processor, such as high gate-count FPGA technology or ASICs to realize a wideband IF receiver. DSP operations implemented in the DRX can include quadrature demodulation and multi-rate, variable-bandwidth IF filtering. Pulse-to-pulse (Doppler domain) filtering can also be implemented in the form of a presummer (accumulator) and an azimuth prefilter. An out of band noise source can be employed to provide a dither signal to the ADC, and later be removed by digital signal processing. Both the range and Doppler domain filtering operations can be implemented using a unique pane architecture which allows on-the-fly selection of the filter decimation factor, and hence, the filter bandwidth. The DRX module can include a standard VME-64 interface for control, status, and programming. An interface can provide phase history data to the real-time image formation processors.

US Patent:

7864097, Jan 4, 2011

Filed:

Jan 6, 2009

Appl. No.:

12/349137

Inventors:

Richard C. Ormesher - Albuquerque NM, US
Bertice L. Tise - Albuquerque NM, US

Assignee:

Sandia Corporation - Albuquerque NM

International Classification:

G01S 13/08

US Classification:

342 51, 342 42

Abstract:

In radar transponder operation, a variably delayed gating signal is used to gate a received radar pulse and thereby produce a corresponding gated radar pulse for transmission back to the source of the received radar pulse. This compensates for signal distortion due to amplitude modulation on the retransmitted pulse.

US Patent:

8400349, Mar 19, 2013

Filed:

Jul 27, 2010

Appl. No.:

12/844576

Inventors:

Dale F. Dubbert - Cedar Crest NM, US
Bertice L. Tise - Albuquerque NM, US

Assignee:

Sandia Corporation - Albuquerque NM

International Classification:

G01S 13/58

US Classification:

342113, 342128, 342129

Abstract:

The spurious-free dynamic range of a wideband radar system is increased by apportioning de-ramp processing across analog and digital processing domains. A chirp rate offset is applied between the received waveform and the reference waveform that is used for downconversion to the intermediate frequency (IF) range. The chirp rate offset results in a residual chirp in the IF signal prior to digitization. After digitization, the residual IF chirp is removed with digital signal processing.

US Patent:

47961988, Jan 3, 1989

Filed:

Oct 17, 1986

Appl. No.:

6/919994

Inventors:

Karlan D. Boultinghouse - Sandia Park NM
J. Lee Schoeneman - Albuquerque NM
Bertice L. Tise - Albuquerque NM

Assignee:

The United States of America as represented by the United States
Department of Energy - Washington DC

International Classification:

G01N 2186

US Classification:

364513

Abstract:

A low power, narrow laser beam, generated by a laser carried by a mobile vehicle, is rotated about a vertical reference axis as the vehicle navigates within a structured environment. At least three stationary retroreflector elements are located at known positions, preferably at the periphery of the structured environment, with one of the elements having a distinctive retroreflection. The projected rotating beam traverses each retroreflector in succession, and the corresponding retroreflections are received at the vehicle and focussed on a photoelectric cell to generate corresponding electrical signals. The signal caused by the distinctive retroreflection serves as an angle-measurement datum. An angle encoder coupled to the apparatus rotating the projected laser beam provides the angular separation from this datum of the lines connecting the mobile reference axis to successive retroreflectors. This real-time angular data is utilized with the known locations of the retroreflectors to trigonometrically compute using three point resection, the exact real-time location of the mobile reference axis (hence the navigating vehicle) vis-a-vis the structured environment, e. g.