Ronald Martin Hatch

US Patent:

6347113, Feb 12, 2002

Filed:

Nov 9, 1999

Appl. No.:

09/437108

Inventors:

Ronald R. Hatch - Wilmington CA

Assignee:

NavCom Technology, Inc. - Redondo Beach CA

International Classification:

H04K 100

US Classification:

375149, 375150

Abstract:

A Global Positioning System receiver includes an intermediate frequency (IF) processor configured to downconvert broadcast signal to generate a first channel signal which is further downconverted to recover a PRN signal by an angle rotator. The receiver further includes a signal generator configured to generate N gated PRN signals. The N gated PRN signals are generated based on a local replica PRN signal time-divided by M intervals within a chip period of the local replica PRN signal. N and M are positive integers. A number of correlators is also provided. Each of which the correlators are configured to multiply a respective one of N gated PRN signals with the PRN signal to generate a number of correlation values. The correlation values are utilized to monitor distortions in the broadcast signal and/or to track the PRN signal with the local replica PRN signal. Further, methods of monitoring and/or tracking the PRN signal with the local replica PRN signal by utilizing the correlation values are also provided.

US Patent:

6603803, Aug 5, 2003

Filed:

Mar 7, 2000

Appl. No.:

09/520152

Inventors:

Ronald R. Hatch - Wilmington CA

Assignee:

Navcom Technology, Inc. - Redondo Beach CA

International Classification:

H04B 1707

US Classification:

375150, 375142, 375326, 375343, 34235707

Abstract:

A Global Positioning System receiver includes an intermediate frequency (IF) processor configured to downconvert broadcast signal to generate a first channel signal which is further downconverted to recover a PRN signal by an angle rotator. The receiver further includes a signal generator configured to generate N gated PRN signals. The N gated PRN signals are generated based on a local replica PRN signal time-divided by M intervals within a chip period of the local replica PRN signal. N and M are positive integers. A number of correlators is also provided. Each of which the correlators are configured to multiply a respective one of N gated PRN signals with the PRN signal to generate a number of correlation values. The correlation values are utilized to monitor distortions in the broadcast signal and/or to track the carrier frequency signal. Further, a corresponding method is also provided.

US Patent:

6753810, Jun 22, 2004

Filed:

Jan 7, 2003

Appl. No.:

10/338264

Inventors:

Yunchun Yang - Harbor City CA
Ronald R. Hatch - Wilmington CA
Richard T. Sharpe - Torrance CA

Assignee:

NavCom Technology, Inc. - Torrance CA

International Classification:

H04B 7185

US Classification:

34235714, 34235706

Abstract:

A method of fast GPS carrier phase integer ambiguity resolution is based on properties of a Residual Sensitivity Matrix (S matrix), which directly relates a set of integer ambiguities to carrier phase residuals. In one embodiment, the method uses the singular value decomposition of the S Matrix to split the integer ambiguity set into two integer ambiguity subsets and to derive a relationship between the two integer ambiguity subsets. Thus, searching for the integer ambiguity set is reduced to searching for one of the two integer ambiguity subsets, resulting in greatly reduced search space. In an alternative embodiment, a portion of the rows of the S matrix that are linearly independent rows are selected and the S matrix is rearranged according to the selection. The rearranged S matrix is then split into four sub-matrices, which are used to relate the two integer ambiguity subsets.

US Patent:

6864836, Mar 8, 2005

Filed:

Sep 5, 2003

Appl. No.:

10/656956

Inventors:

Ronald R. Hatch - Wilmington CA, US
Richard T. Sharpe - Torrance CA, US
Yunchun Yang - Harbor City CA, US

Assignee:

Navcom Technology, Inc. - Torrance CA

International Classification:

G01S005/02
H04B007/185

US Classification:

34235715, 34235706

Abstract:

A method for detecting and identifying a faulty measurement among a plurality of GPS measurements, obtained by a GPS receiver with respect to a plurality of satellites in view of the GPS receiver, determines whether the plurality of GPS measurements include a faulty measurement. In response to a determination that the plurality of GPS measurements include a faulty measurement, the method identifies a satellite contributing the faulty measurement by computing a correlation value associated with each of the plurality of satellites, and selecting a satellite associated with a highest correlation value as the satellite contributing the faulty measurement.

US Patent:

6934632, Aug 23, 2005

Filed:

Oct 8, 2003

Appl. No.:

10/682553

Inventors:

Ronald R. Hatch - Wilmington CA, US

Assignee:

NavCom Technology, Inc. - Torrance CA

International Classification:

G01C021/00

US Classification:

701213

Abstract:

A method for generating an ambiguity-resolved, refraction-corrected, and noise-minimized carrier-phase measurement. The method includes forming a first composite measurement using GPS carrier-phase measurements on the L1, L2 and L5 frequencies. To reduce the noise in the first composite measurement, the method further includes forming a second composite measurement using GPS carrier-phase measurements on at least two of the three GPS carrier frequencies. The second composite measurement is formed to have a small multi-path noise therein so that it can be used to smooth the first composite measurement so that the multipath noise is minimized.

US Patent:

7071870, Jul 4, 2006

Filed:

Jul 13, 2005

Appl. No.:

11/181410

Inventors:

Richard T. Sharpe - Torrance CA, US
Frederick W. Nelson - Waukee IA, US
Terence D. Pickett - Waukee IA, US
Ronald R. Hatch - Wilmington CA, US
Yunchun Yang - Harbor City CA, US

Assignee:

Navcom Technology, Inc. - Torrance CA

International Classification:

H04B 7/185
G01S 5/14

US Classification:

34235704, 34235703

Abstract:

The present invention includes a method for a combined use of a local RTK system and a regional, wide-area, or global differential carrier-phase positioning system (WADGPS) in which disadvantages associated with the RTK and the WADGPS navigation techniques when used separately are avoided. The method includes determining a floating ambiguity value and a first position of an object using WADGPS in a first mode of operation, and determining a second position of the object using the local RTK system in a second mode of operation.

US Patent:

7117417, Oct 3, 2006

Filed:

Jul 30, 2003

Appl. No.:

10/630302

Inventors:

Richard T. Sharpe - Torrance CA, US
Ronald R. Hatch - Wilmington CA, US
Frederick W. Nelson - Waukee IA, US

Assignee:

Navcom Technology, Inc. - Torrance CA

International Classification:

G06F 11/00
G01S 1/00
G01C 21/26

US Classification:

714746, 34235702, 34235712, 701214

Abstract:

A method for generating satellite clock corrections for a WADGPS network computers satellite clock corrections after removing other substantial error components. Errors caused by the ionosphere refraction effects are removed from GPS measurements taken at reference stations using dual-frequency GPS measurements. The multipath noise are removed by smoothing of GPS pseudorange code measurements with carrier-phase measurements. The tropospheric refraction effect can be largely removed by modeling, and if desired, can be improved by the use of small stochastic adjustments included in the computation of the clock correction. After removing the above error factors, satellite clock corrections are computed for individual reference stations, and an average clock correction is formed for each of a plurality of satellites by taking an average or weighted average of the satellite clock corrections over reference stations to which the satellite is visible.

US Patent:

7119741, Oct 10, 2006

Filed:

Jan 13, 2004

Appl. No.:

10/757340

Inventors:

Richard T. Sharpe - Torrance CA, US
Frederick W. Nelson - Waukee IA, US
Terence D. Pickett - Urbandale IA, US
Ronald R. Hatch - Wilmington CA, US
Yunchun Yang - Harbor City CA, US

Assignee:

Navcom Technology, Inc. - Torrance CA

International Classification:

H04B 7/185
G01S 5/14

US Classification:

34235704, 34235703

Abstract:

The present invention includes a method for a combined use of a local RTK system and a regional, wide-area, or global differential carrier-phase positioning system (WADGPS) in which disadvantages associated with the RTK and the WADGPS navigation techniques when used separately are avoided. The method includes using a known position of a user receiver that has been stationary or using an RTK system to initialize the floating ambiguity values in the WADGPS system when the user receiver is moving. Thereafter, the refraction-corrected carrier-phase measurements obtained at the user GPS receiver are adjusted by including the corresponding initial floating ambiguity values and the floating ambiguity values are treated as well known (small variance) in subsequent processes to position the user receiver in the WADGPS system.