Navcom Technology, Inc.

Deere + Company

Richard T Sharpe

Ronald R Hatch

Daniel J Eslinger

Yunchun Yang

Liwen L Dai

Frederick William Nelson

Terence Daniel Pickett

Chaochao Wang

Jing Sun

Terrence D Pickett

A reusable wreath frame assembly for supporting and retaining wreath material. The reusable wreath frame assembly includes a frame and a multi-link fastening assembly. The frame forms a wreath back and is configured to extend adjacent the wreath material. The multi-link fastening assembly extends from the frame. The multi-link fastening assembly is operative to assume a fastened mode and an unfastened mode. The multi-link fastening assembly secures the wreath material to the frame when in the fastened mode. When the multi-link fastening assembly is in the unfastened mode, the wreath material can be placed on the frame.

Reusable wreath frame assembly

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

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

A method and system are provided to determine a relative position vector between primary receiver associated with a reference station and secondary receiver associated with a user. The method and system determine a position of the reference station at the reference station according to signals received thereat from a plurality of satellites, determine a position of the user receiver at the user based on measurements obtained thereat and on error corrections computed at the reference station, and compute the relative position vector by differencing the position of the reference station and the position of the user.

Moving reference receiver for RTK navigation

The present invention includes a process for navigating an object according to signals from satellites by propagating the position of the object forward in time using successive changes in the carrier-phase measurements. The process computes at a low rate matrices required for solving for the position of the objects, and repeatedly uses the most recently computed matrices to compute position updates at a high rate until the next low-rate computation is completed.

GPS navigation using successive differences of carrier-phase measurements

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.

Method for combined use of a local RTK system and a regional, wide-area, or global carrier-phase positioning system

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.

Method for generating clock corrections for a wide-area or global differential GPS system

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.

Method for combined use of local positioning system and a global positioning system

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.

Method for receiver autonomous integrity monitoring and fault detection and elimination

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.

Growing community of inventors

Torrance, CA, United States of America

Richard T Sharpe