Abstract: Systems and methods for friction detection and slippage control are provided. In one embodiment, a method for detection and slippage control comprises: measuring vehicle motion, the motion providing data including at least lateral acceleration, longitudinal acceleration and yaw; measuring wheel rotation rates; estimating wheel rotation rates based on the measured vehicle motion, the measured wheel rotation rates, and a vehicle model; estimating a wheel coefficient of friction based the estimated wheel rotation rates, the measured wheel rotation rates, and the vehicle motion; calculating one or both of a road coefficient of friction and a wheel slippage; and producing an output signal representing on one or both of the road coefficient of friction and wheel slippage. When measuring vehicle motion provides less than six-degree-of-freedom measurements, the method further comprises at least one of: detecting driver input; and determining vehicle position from a GNSS signal.

Abstract: Methods and apparatus for navigating with the use of correlation within a select area are provided. One method includes, storing data required to reconstruct ranges and associated angles to objects along with statistical accuracy information while initially traversing throughout the select area. Measuring then current ranges and associated angles to the objects during a subsequent traversal throughout the select area. Correlating the then current ranges and associated angles to the objects to reconstructed ranges and associated angles to the objects from the stored data. Determining at least one of then current location and heading estimates within the select area based at least in part on the correlation and using the least one of the then current location and heading estimates for navigation.

Abstract: An electronic protection system for an articulated vehicle comprises a lead sensor configured to detect yaw rotational rate of a lead portion about a first yaw axis; a load sensor configured to detect yaw rotational rate of a load portion about a second yaw axis; and a processing unit coupled to the lead sensor and the load sensor, wherein the processing unit is configured to determine when to initiate corrective controls based at least in part on the data received from the lead sensor and the load sensor.

Abstract: A method for characterizing distortions in the earth's magnetic field caused by a vehicle having a magnetometer affixed therein is described. The method includes repeatedly measuring the distorted magnetic field utilizing the magnetometer and obtaining a three-dimensional orientation of the vehicle axes with respect to the earth at a time of each magnetometer measurement. The method also includes receiving undistorted earth magnetic field data for the vicinity of the vehicle relative to the earth at the time of each magnetometer measurement and characterizing distortions caused by one or more of the vehicle and magnetometer errors utilizing the magnetic field measurements, the orientations of the vehicle, and the undistorted earth magnetic field data.

Abstract: An arrangement and appertaining method utilizing the arrangement provides a cost effective way to implement an accurate and cost effective satellite positioning differential augmentation system. This hybrid system integrates a network of Ground Based Augmentation Systems (GBAS) with a Satellite Based Augmentation System (SBAS), permitting the high integrity features of the GBAS to be utilized with the much broader coverage area of the SBAS system without requiring significant expenditures that would be required for upgrading either of the systems independently.

Abstract: A method for characterizing distortions in the earth's magnetic field caused by a vehicle having a magnetometer affixed therein is described. The method includes repeatedly measuring the distorted magnetic field utilizing the magnetometer and obtaining a three-dimensional orientation of the vehicle axes with respect to the earth at a time of each magnetometer measurement. The method also includes receiving undistorted earth magnetic field data for the vicinity of the vehicle relative to the earth at the time of each magnetometer measurement and characterizing distortions caused by one or more of the vehicle and magnetometer errors utilizing the magnetic field measurements, the orientations of the vehicle, and the undistorted earth magnetic field data.

Abstract: An arrangement and appertaining method utilizing the arrangement provides a cost effective way to implement an accurate and cost effective satellite positioning differential augmentation system. This hybrid system integrates a network of Ground Based Augmentation Systems (GBAS) with a Satellite Based Augmentation System (SBAS), permitting the high integrity features of the GBAS to be utilized with the much broader coverage area of the SBAS system without requiring significant expenditures that would be required for upgrading either of the systems independently.

Abstract: A fail operational system including two sets of first and second sensors responsive to different stimuli to produce signals indicative of a condition, and a comparator for comparing the outputs of the first and second sensors to produce a "valid" signal when the outputs are substantially the same.

Abstract: A differential ground station repeater in which a plurality of transmitters are utilized to relay information to an aircraft from a single ground station situated to receive satellite information and to transmit the satellite and other information to the plurality of correction transmitters in which the transmitters utilize a single frequency but transmit at different described sub-time slots so that the aircraft may utilize the signal of any of the transmitters it may be receiving signals.

Abstract: A pair of antennae in combination with a GPS signal receiver system is employed for detecting the reception of satellite information signals from a spoofing signal transmitter as opposed to those satellite information signals transmitted aboard each of the satellite vehicles which form a satellite positioning system. As described herein, an indication of the pointing angle between the antennae and the actual transmitter transmitting the satellite information signals is detected. The pointing angle and/or alternatively the range difference may be observed by monitoring the behavior of the pseudo random code associated with the carrier of the satellite information signal, or the carrier itself. In turn, pseudo range measurements, pseudo range rate measurements, carrier phase measurements, and or Doppler count measurement associated with the two antennae may be use to obtain the desired discriminant.

Abstract: A method and apparatus are provided for predicting the position error bound in a satellite positioning system at a future time. The future position of each satellite at the future time is predicted from the trajectory data obtained from each satellite. The predicted position for each satellite and the estimated position of the satellite positioning system receiver is then used to generate a line of sight matrix at a future time, from which a position error bound value determined.

Abstract: An aircraft landing system is disclosed in which a differential GPS global positioning system is employed. A ground station, located in the vicinity of one or more landing strips, includes a GPS receiver and a data link transmitter for transmitting GPS correction data and also the global position of two points which define a desired aircraft glide path associated with a particular landing strip. The system further includes aircraft equipment comprising a receiver for receiving the correction data and the global position of the two glide path points, and a GPS receiver. The aircraft equipment further includes a computer for determining a corrected global position of the aircraft as a function of the aircraft GPS range data and the correction data, and subsequently determines the lateral deviation and vertical deviation from the glide path defined by the two glide path points.