Disclosed is a method for automatically controlling a blade of a motor grader. At least one global navigation satellite system (GNSS) antenna and at least one inertial measurement unit (IMU) are mounted on the motor grader. No GNSS antenna is mounted on the blade; and no pole is used for mounting. With each GNSS antenna, GNSS navigation signals are received, and a position of each GNSS antenna is computed. With each IMU, three orthogonal accelerations and three orthogonal angular rotation rates are measured. With at least one processor, a blade position and a blade orientation are computed, based at least in part on the GNSS and IMU measurements. The blade elevation and the blade slope angle (and, in some embodiments, the blade side shift) are automatically controlled, based at least in part on the computed blade position, the computed blade orientation, and a digital job site model.

Disclosed embodiments pertain to a method on a UE may comprise determining a first absolute position of the UE at a first time based on GNSS measurements from a set of satellites. At a second time subsequent to the first time, the UE may determine a first estimate of displacement of the UE relative to the first absolute position using non-GNSS measurements. Further, at the second time, the UE may also determine a second estimate of displacement relative to the first absolute position and/or a second absolute position of the UE based, in part, on: the GNSS carrier phase measurements at the first time from the set of satellites, and GNSS carrier phase measurements at the second time from a subset comprising two or more satellites of the set of satellites, and the first estimate of displacement of the UE.

Disclosed embodiments pertain to a method on a UE may comprise determining a first absolute position of the UE at a first time based on GNSS measurements from a set of satellites. At a second time subsequent to the first time, the UE may determine a first estimate of displacement of the UE relative to the first absolute position using non-GNSS measurements. Further, at the second time, the UE may also determine a second estimate of displacement relative to the first absolute position and/or a second absolute position of the UE based, in part, on: the GNSS carrier phase measurements at the first time from the set of satellites, and GNSS carrier phase measurements at the second time from a subset comprising two or more satellites of the set of satellites, and the first estimate of displacement of the UE.

A system and related methods for determining precision navigation solutions decorrelates GPS carrier-phase ambiguities derived from multiple-source GPS information via Least-squares AMBiguity Decorrelation Adjustment (LAMBDA) algorithms, and fixes a subset of the decorrelated integer ambiguities within the LAMBDA domain. To maintain high accuracy, a partial almost fix solution is generated using the subset of the decorrelated ambiguities to be fixed in the LAMBDA domain. The subset of decorrelated ambiguities is used to compute protection levels and the probability of almost fix (PAF), or that the navigation solution corresponding to the decorrelated ambiguities is within the region of correctly-fixed or low-error almost-fixed ambiguities. The partial list of fixed ambiguities is used to generate the optimal navigation solution (floating-point, partial almost-fix, or fully fixed) while maintaining protection levels within alert limits and PAF above the desired threshold.

A system and related methods for determining precision navigation solutions decorrelates GPS carrier-phase ambiguities derived from multiple-source GPS information via Least-squares AMBiguity Decorrelation Adjustment (LAMBDA) algorithms, and fixes a subset of the decorrelated integer ambiguities within the LAMBDA domain. To maintain high accuracy, a partial almost fix solution is generated using the subset of the decorrelated ambiguities to be fixed in the LAMBDA domain. The subset of decorrelated ambiguities is used to compute protection levels and the probability of almost fix (PAF), or that the navigation solution corresponding to the decorrelated ambiguities is within the region of correctly-fixed or low-error almost-fixed ambiguities. The partial list of fixed ambiguities is used to generate the optimal navigation solution (floating-point, partial almost-fix, or fully fixed) while maintaining protection levels within alert limits and PAF above the desired threshold.

Systems and methods for vehicle attitude determination are provided. In one embodiment, a method for vehicle orientation detection comprises: generating differenced carrier phase measurements based on measurements from an on-board GNSS Receiver System; receiving attitude aiding measurements and a baseline length from on-board aiding sources; calculating float ambiguity values with associated covariance values as a function of the differenced carrier phase measurements, attitude aiding measurements and baseline length; calculating a set of integer candidate arrays from the float ambiguity values, wherein the integer candidate arrays are calculated from dis-similar ambiguity estimation algorithms; selecting a first integer candidate array as resolved integer values as a function of residuals calculated from the differenced carrier phase measurements and the attitude aiding measurements and the baseline length and further based on comparing the plurality of residuals to a plurality of thresholds; and outputting the resolved integer values to an attitude and heading calculator.

Systems and methods for vehicle attitude determination are provided. In one embodiment, a method for vehicle orientation detection comprises: generating differenced carrier phase measurements based on measurements from an on-board GNSS Receiver System; receiving attitude aiding measurements and a baseline length from on-board aiding sources; calculating float ambiguity values with associated covariance values as a function of the differenced carrier phase measurements, attitude aiding measurements and baseline length; calculating a set of integer candidate arrays from the float ambiguity values, wherein the integer candidate arrays are calculated from dis-similar ambiguity estimation algorithms; selecting a first integer candidate array as resolved integer values as a function of residuals calculated from the differenced carrier phase measurements and the attitude aiding measurements and the baseline length and further based on comparing the plurality of residuals to a plurality of thresholds; and outputting the resolved integer values to an attitude and heading calculator.

Methods and apparatus are disclosed for gathering raw Global Navigation Satellite Systems (GNSS) phase measurements at a GNSS receiver and making them available to a remote device for processing to calculate a position fix for the GNSS receiver. The measurements are arranged in a first subset and a second subset. First bits of the first subset and second bits of the second subset are embedded in one or more data messages for transmission to the remote device. The first bits include a coarse part and a fine part of the respective phase measurement. In contrast, the second bits describe at least a portion of the fine part, but none of the coarse part, of the respective phase measurement.

Methods and apparatus are disclosed for gathering raw Global Navigation Satellite Systems (GNSS) phase measurements at a GNSS receiver and making them available to a remote device for processing to calculate a position fix for the GNSS receiver. The measurements are arranged in a first subset and a second subset. First bits of the first subset and second bits of the second subset are embedded in one or more data messages for transmission to the remote device. The first bits include a coarse part and a fine part of the respective phase measurement. In contrast, the second bits describe at least a portion of the fine part, but none of the coarse part, of the respective phase measurement.

A small-sized state calculating device which may acquire a highly-precise state calculation value is provided. The state calculating device may include antennas, receiving parts, a phase difference calculating part and an operation part. The receiving parts may calculate carrier phase measurements PY.sub.A, PY.sub.B and PY.sub.C of GNSS signals received by the antennas, respectively. The phase difference calculating part may set the antennas to be switched between a master antenna and a slave antenna, and calculate the plurality of inter-antenna phase differences .sub.AB, .sub.BC and .sub.CA, for every combination of the master antenna and the slave antenna, using the carrier phase measurements PY.sub.A, PY.sub.B and PY.sub.C. The operation part may calculate an attitude angle AT using the plurality of inter-antenna phase differences .sub.AB, .sub.BC and .sub.CA.