Navcom Technology, Inc.

Deere + Company

Daniel J Eslinger

Liwen L Dai

Ronald R Hatch

Richard T Sharpe

Chaochao Wang

Terence Daniel Pickett

Frederick William Nelson

Yunfeng Shao

John Perry Genta

Jing Sun

Liwen Dai

A method and system for estimating the position comprises measuring a first carrier phase of a first carrier signal and a second carrier phase of a second carrier signal received by a location-determining receiver. A primary real time kinematic (RTK) engine or receiver data processing system estimates a primary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carder phase. A quality evaluator determines if a primary integer ambiguity set is resolved correctly to the predefined reliability rate during an earlier evaluation period. A secondary real time kinematic (RTK) engine or receiver data processing system estimates a secondary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carrier phase during a later period following the earlier evaluation period.

Method and system for estimating position using dual real time kinematic engines

A system and method for determining the heading angle of a vehicle includes first and second antennas associated with the vehicle. The first and second antennas are configured to receive signals comprising global positioning system data. A receiver front end is configured to receive the signals comprising global positioning system data. An electronic data processor is capable of receiving the global positioning system data from the receiver front end. The data processor is configured or programmed to execute a method to determine the attitude of the vehicle which may include the heading angle of the vehicle.

System and method for determining the heading angle of a vehicle

A method and system for estimating the position comprises measuring a first carrier phase of a first carrier signal and a second carrier phase of a second carrier signal received by a location-determining receiver. A primary real time kinematic (RTK) engine or receiver data processing system estimates a primary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carrier phase. A quality evaluator determines if a primary integer ambiguity set is resolved correctly to the predefined reliability rate during an earlier evaluation period. A secondary real time kinematic (RTK) engine or receiver data processing system estimates a secondary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carrier phase during a later period following the earlier evaluation period.

A method for mitigating atmospheric errors in code and carrier phase measurements based on signals received from a plurality of satellites in a global navigation satellite system is disclosed. A residual tropospheric delay and a plurality of residual ionospheric delays are modeled as states in a Kalman filter. The state update functions of the Kalman filter include at least one baseline distance dependant factor, wherein the baseline distance is the distance between a reference receiver and a mobile receiver. A plurality of ambiguity values are modeled as states in the Kalman filter. The state update function of the Kalman filter for the ambiguity states includes a dynamic noise factor. An estimated position of mobile receiver is updated in accordance with the residual tropospheric delay, the plurality of residual ionospheric delays and/or the plurality of ambiguity values.

Distance dependent error mitigation in real-time kinematic (RTK) positioning

Distance dependant error mitigation in real-time kinematic (RTK) positioning

In a method of mitigating errors in satellite navigation measurements at a satellite navigation receiver, respective single-frequency signals are received from respective satellites in a plurality of satellites in a satellite navigation system. Pseudorange and carrier-phase measurements corresponding to respective received single-frequency signals are calculated. These calculations include filtering the pseudorange and carrier-phase measurements in a Kalman filter having a state vector comprising a plurality of states, including a position state, a receiver clock state, and a plurality of bias states. Each bias state corresponds to a respective satellite in the plurality of satellites. The filtering includes updating the state vector. An estimated position of the satellite navigation receiver is updated in accordance with an update to the state vector.

Methods and systems to increase accuracy in the navigation of single frequency receivers

A method for performing integer ambiguity resolution in a global navigation satellite system is disclosed. A set of ambiguities, which are associated with carrier phase measurements of at least some of the signals received from the satellites in an identified set of satellites, are identified. Integer ambiguities are estimated and a best candidate set and a second best candidate set of integer ambiguity values are determined. Upon determining that the best set of integer ambiguity values fail to meet a discrimination test, each ambiguity for which integer ambiguity values in the best candidate set and second best candidate set fail to meet predefined criteria are removed from the set of ambiguities to produce a reduced set of ambiguities. The integer ambiguities in the reduced set of ambiguities are then resolved and an output is generated in accordance with the resolved integer ambiguities.

Partial search carrier-phase integer ambiguity resolution

A mobile satellite navigation receiver for calculating an offset between a local positioning system and a wide-area satellite positioning system is presented. The mobile satellite navigation receiver determines a first solution of a position of the mobile satellite navigation receiver relative to a first local positioning system, wherein the first local positioning system includes one or more reference receivers at known locations. The mobile satellite navigation receiver determines a second solution of the position of the satellite navigation receiver relative to a wide-area differential satellite positioning system. The mobile satellite navigation receiver then calculates an offset between the first solution and the second solution.

Navigation receiver and method for combined use of a standard RTK system and a global carrier-phase differential positioning system

The present invention includes a method for a combined use of a local positioning system, a local RTK system and a regional, wide-area, or global differential carrier-phase positioning system (WADGPS) in which disadvantages associated with the local positioning system, the RTK and the WADGPS navigation techniques when used separately are avoided. The method includes determining a first position of the object based on information from the WADGPS, and determining a second position of the object based on position information from a local positioning/RTK positioning system. Thereafter, position determined by the WADGPS and the position determined by the local positioning/RTK positioning system are compared. The WADGPS position is used for navigating the object when the WADGPS position and local positioning/position differ by more than a predefined threshold, and using the local positioning/RTK position for navigating the object when the WADGPS position and local positioning/RTK position differ by less than the predefined threshold.

Method for increasing the reliability of position information when transitioning from a regional, wide-area, or global carrier-phase differential navigation (WADGPS) to a local real-time kinematic (RTK) navigation system

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Huntington Beach, CA, United States of America

Daniel J Eslinger