Abstract: A relative navigation system comprising of a pair of Global Navigation Satellite System (GNSS) and Inertial Navigation System (INS) units that communicate to provide updated position, velocity and attitude information from a master to a rover. The rover unit produces a carrier based solution that enables the system to reduce the uncorrelated low latency position error between the master and the rover units to less than 50 cm.

Abstract: In an example embodiment, motion is detected with an IMU utilizing standard deviation. Specifically, an IMU may obtains IMU measurements. An IMU motion detection process may accumulate a particular number of IMU measurements over a time interval to calculate an absolute magnitude of earth rate (ERimu) value and an absolute magnitude of normal gravity value (GNimu). The values calculated may be referred to as a sample. The IMU motion detection process may create sample rolling histories based on a particular number of samples, e.g., consecutive samples. The IMU motion detection process may then calculate standard deviation values for a sample rolling history based on the ERimu and GNimu values included in the sample rolling history. The IMU motion detection process may compare the standard deviation values to respective motion threshold values, which may be adaptive, to determine if a body of interest, e.g., vehicle, is moving or is stationary.

Abstract: A system and method for dead reckoning for marine positioning applications is provided. After INS mechanization, an exponential moving average (EMA) is calculated that is used to generate an update for a Kalman filter. The use of the EMA allows the system to limit position error in a linear fashion while being self-contained.

Abstract: A system operating in a dead reckoning mode accumulates relative yaw measurements, i.e., measurements of rotation about a z-axis, made by one or more over mechanization update intervals and produces dead reckoning mechanization update values. The system accumulates the values over a turn rate accumulation period, calculates a yaw rate and determines if the yaw rate exceeds a turn rate threshold. If so, the system directs an INS filter to perform a zero yaw rate update at the start of a next mechanization update interval, to correct for the z-axis drift errors of the gyroscopes based on the sensed rotation in the relative yaw measurements over the previous mechanization update interval. The system then sets the z-axis drift errors to zero. If the system determines that the yaw rate exceeds the turn rate threshold, the zero yaw rate update is not performed at the start of the next mechanization update interval.

Abstract: A relative navigation system comprising of a pair of Global Navigation Satellite System (GNSS) and Inertial Navigation System (INS) units that communicate to provide updated position, velocity and attitude information from a master to a rover. The rover unit produces a carrier based solution that enables the system to reduce the uncorrelated low latency position error between the master and the rover units to less than 50 cm.

Abstract: A relative navigation system comprising of a pair of Global Navigation Satellite System (GNSS) and Inertial Navigation System (INS) units that communicate to provide updated position, velocity and attitude information from a master to a rover. The rover unit produces a carrier based solution that enables the system to reduce the uncorrelated low latency position error between the master and the rover units to less than 50 cm.

Abstract: In an example embodiment, motion is detected with an IMU utilizing standard deviation. Specifically, an IMU may obtains IMU measurements. An IMU motion detection process may accumulate a particular number of IMU measurements over a time interval to calculate an absolute magnitude of earth rate (ERimu) value and an absolute magnitude of normal gravity value (GNimu). The values calculated may be referred to as a sample. The IMU motion detection process may create sample rolling histories based on a particular number of samples, e.g., consecutive samples. The IMU motion detection process may then calculate standard deviation values for a sample rolling history based on the ERimu and GNimu values included in the sample rolling history. The IMU motion detection process may compare the standard deviation values to respective motion threshold values, which may be adaptive, to determine if a body of interest, e.g., vehicle, is moving or is stationary.

Abstract: A system operating in a dead reckoning mode accumulates relative yaw measurements, i.e., measurements of rotation about a z-axis, made by one or more over mechanization update intervals and produces dead reckoning mechanization update values. The system accumulates the values over a turn rate accumulation period, calculates a yaw rate and determines if the yaw rate exceeds a turn rate threshold. If so, the system directs an INS filter to perform a zero yaw rate update at the start of a next mechanization update interval, to correct for the z-axis drift errors of the gyroscopes based on the sensed rotation in the relative yaw measurements over the previous mechanization update interval. The system then sets the z-axis drift errors to zero. If the system determines that the yaw rate exceeds the turn rate threshold, the zero yaw rate update is not performed at the start of the next mechanization update interval.

Abstract: A navigation system that utilizes yaw rate constraint during inertial dead reckoning is provided. The system accumulates relative yaw measurements to produce dead reckoning mechanization update values. The system corrects for z axis drift errors.

Abstract: A relative navigation system comprising of a pair of Global Navigation Satellite System (GNSS) and Inertial Navigation System (INS) units that communicate to provide updated position, velocity and attitude information from a master to a rover. The rover unit produces a carrier based solution that enables the system to reduce the uncorrelated low latency position error between the master and the rover units to less than 50 cm.

Abstract: A system operating in a dead reckoning mode accumulates relative yaw measurements, i.e., measurements of rotation about a z-axis, made by one or more over mechanization update intervals and produces dead reckoning mechanization update values. The system accumulates the values over a turn rate accumulation period, calculates a yaw rate and determines if the yaw rate exceeds a turn rate threshold. If so, the system directs an INS filter to perform a zero yaw rate update at the start of a next mechanization update interval, to correct for the z-axis drift errors of the gyroscopes based on the sensed rotation in the relative yaw measurements over the previous mechanization update interval. The system then sets the z-axis drift errors to zero. If the system determines that the yaw rate exceeds the turn rate threshold, the zero yaw rate update is not performed at the start of the next mechanization update interval.

Abstract: A system and method for providing location information using a long baseline accelerometer/GNSS system. A first set of accelerometers is operatively associated with the first GNSS antenna while a second set of accelerometers is operatively associated with a second (or more) GNSS antenna. The multiple assemblies are separated by predefined distances and held rigid to each other. Accelerometer data is combined with the GNSS data to provide improved navigation and location information.

Abstract: A system and method for providing location information using a long baseline accelerometer/GNSS system. A first set of accelerometers is operatively associated with the first GNSS antenna while a second set of accelerometers is operatively associated with a second (or more) GNSS antenna. The multiple assemblies are separated by predefined distances and held rigid to each other. Accelerometer data is combined with the GNSS data to provide improved navigation and location information.

Abstract: A GNSS/INS navigation system includes an INS filter that uses relative yaw values as an observable for attitude updates. The system calculates the relative yaw values based on carrier phase measurements, e.g., phase windup measurements, of GNSS signals received at a system GNSS antenna. The use of the relative yaw values as an observable in the INS filter allows the system to improve estimates of associated biases, and also to continue to estimate the associated biases in low dynamic environments.

Abstract: A GNSS/INS navigation system includes an INS filter that uses relative yaw values as an observable for attitude updates. The system calculates the relative yaw values based on carrier phase measurements, e.g., phase windup measurements, of GNSS signals received at a system GNSS antenna. The use of the relative yaw values as an observable in the INS filter allows the system to improve estimates of associated biases, and also to continue to estimate the associated biases in low dynamic environments.

Abstract: A navigation system for use with moving vehicles includes target points proximate to a rendezvous site located on a first moving vehicle. One or more transmitters broadcast target point positioning information. A navigation unit on a second moving vehicle utilizes a camera to capture images that include the target points or a detector system that emits one or more beams to the target points. The navigation unit determines the relative position and orientation of the rendezvous site at the second vehicle. The navigation unit utilizes the relative position and orientation and an absolute position and orientation of the rendezvous site calculated from the target position information and calculates an absolute position and orientation corresponding to the second vehicle. The navigation unit then initializes its component inertial subsystem using a local position and orientation that are based on the calculated absolute position and orientation of the second vehicle.

Abstract: A navigation system for use with moving vehicles includes target points proximate to a rendezvous site located on a first moving vehicle. One or more transmitters broadcast target point positioning information. A navigation unit on a second moving vehicle utilizes a camera to capture images that include the target points or a detector system that emits one or more beams to the target points. The navigation unit determines the relative position and orientation of the rendezvous site at the second vehicle. The navigation unit utilizes the relative position and orientation and an absolute position and orientation of the rendezvous site calculated from the target position information and calculates an absolute position and orientation corresponding to the second vehicle. The navigation unit then initializes its component inertial subsystem using a local position and orientation that are based on the calculated absolute position and orientation of the second vehicle.

Abstract: A navigation system for use with moving vehicles includes target points proximate to a rendezvous site located on a first moving vehicle. One or more transmitters associated with the target points broadcast time-tagged target point positioning information. A navigation unit on a second moving vehicle utilizes a camera with known properties to capture images that include the target points. The navigation unit processes the image that corresponds in time to the positioning information, to determine the relative position and orientation of the rendezvous site at the second vehicle. The navigation unit utilizes the relative position and orientation and an absolute position and orientation of the rendezvous site calculated from the target position information and calculates an absolute position and orientation corresponding to the second vehicle.

Abstract: An inertial (“INS”)/GPS receiver uses injected alignment data to determine the alignment of the INS sub-system when the receiver is in motion during start-up. The alignment data is determined from parameterized surface information, measured GPS velocity, and a known or predetermined angular relationship between the vehicle on which the receiver is mounted and an inertial measurement reference, or body, frame associated with the accelerometers and gyroscopes of the inertial measuring unit (“IMU”). The parameterized surface information, which provides a constraint, may be the orientation of the surface over which the vehicle that houses the receiver is moving. The receiver uses the initial GPS position to determine the location of the vehicle on the parameterized surface, and thus, the known surface orientation. The receiver then determines the roll, pitch and heading of the vehicle on the surface using the associated GPS velocity vector.

Abstract: An inertial (“INS”)/GPS receiver includes an INS sub-system which incorporates, into a modified Kalman filter, GPS observables and/or other observables that span previous and current times. The INS filter utilizes the observables to update position information relating to both the current and the previous times, and to propagate the current position, velocity and attitude related information. The GPS observable may be delta phase measurements, and the other observables may be, for example, wheel pick-offs (or counts of wheel revolutions) that are used to calculate along track differences, and so forth. The inclusion of the measurements in the filter together with the current and the previous position related information essentially eliminates the effect of system dynamics from the system model. A position difference can thus be formed that is directly observable by the phase difference or along track difference measured between the previous and current time epochs.