Abstract: A system vitally determines a position of a train. The system includes a plurality of diverse sensors, such as tachometers and accelerometers, structured to repetitively sense at least change in position and acceleration of the train, a global positioning system sensor, which is diverse from each of the diverse sensors, structured to repetitively sense position of the train, and a track map including a plurality of track segments which may be occupied by the train. A processor cooperates with the diverse sensors, the global positioning system sensor and the track map. The processor includes a routine structured to provide measurement uncertainty for each of the diverse sensors and the global positioning system sensor. The routine cross-checks measurements for the diverse sensors, and cross-checks the global positioning system sensor against the track map. The routine provides the vitally determined position of the train and the uncertainty of the vitally determined position.

Abstract: A system comprises an outer shell having an inner spherical cavity and an inner sphere located in the spherical cavity. The inner sphere comprises a sensor; at least three transmit antennas; and at least three transmitters each coupled to the sensor and to a respective one of the at least three transmit antennas. The system comprises at least three receive antennas each located in the spherical cavity, wherein each of the at least three receive antennas is frequency matched to a transmit frequency of a respective one of the at least one transmit antennas. The system also comprises at least three receivers each coupled to a respective one of the at least three receive antennas and a data selection logic circuit configured to select at least one signal from the signals received from each of the at least three receivers based on the respective signal quality of the received signals.

Abstract: Methods and systems for determining reliability of Global Positioning System (GPS) ground speed. An example system receives GPS track information and GPS ground speed, determines a change in GPS track information and determines reliability of the GPS ground speed based on the determined change in GPS track information relative to the GPS ground speed. The system sets a GPS ground speed based on the determined reliability. A GPS ground speed output is set to zero, if the GPS ground speed is determined unreliable and the GPS ground speed output is set to the GPS ground speed, if the GPS ground speed is determined reliable. The system sends the GPS ground speed output to a Runway Awareness and Advisory System (RAAS). Also, the system sets the GPS ground speed output to zero, if a received GPS ground speed validity signal or a received GPS track validity signal indicate invalid.

Abstract: A global navigation satellite sensor system (GNSS) and gyroscope control system for vehicle steering control comprising a GNSS receiver and antennas at a fixed spacing to determine a vehicle position, velocity and at least one of a heading angle, a pitch angle and a roll angle based on carrier phase position differences. The roll angle facilitates correction of the lateral motion induced position errors resultant from motion of the antennae as the vehicle moves based on an offset to ground and the roll angle. The system also includes a control system configured to receive the vehicle position, heading, and at least one of roll and pitch, and configured to generate a steering command to a vehicle steering system. The system includes gyroscopes for determining system attitude change with respect to multiple axes for integrating with GNSS-derived positioning information to determine vehicle position, velocity, rate-of-turn, attitude and other operating characteristics.

Abstract: A method is described for generating a navigation chart. The navigation chart includes a plurality of allocated areas corresponding to symbols for a plurality of chart features. The method includes identifying an unallocated area of the navigation chart proximate to a symbol for one chart feature of the plurality of chart features. A first label and a second label are determined for the one chart feature. The first label includes a plurality of feature attribute indicators, and the second label includes a subset of the plurality of feature attribute indicators. A label is selected from among the first label and the second label based on dimensions of the unallocated area. At least a portion of the unallocated area is allocated to the selected label, and the navigation chart is displayed.

Abstract: A navigation system is described which includes a mobile terminal 100 which has a transmission source receiver 204 for receiving the signals from one or more unsynchronised terrestrial transmission sources 102-105 and a satellite positioning receiver 200 for receiving signals from the satellite or satellites 107-110 of a satellite positioning system. The terminal also has a clock 208. A processor 209 is arranged to acquire a measurement vector having a list of values, each value representing a measurement made by a receiver 200,204, and the terminal clock's bias. It computes a state vector representing the current state of the system, using a previously-determined state vector, the measurement vector, and a dynamic model in order to derive a dynamic navigation solution.

Abstract: A receiving method and apparatus for increasing coherent integration length while receiving a positioning signal from transmitters such as GPS satellites. In order to compensate for frequency drifts that may occur in the positioning signal, a hypothesis is made as to the frequency drift, which is inserted into the receiving algorithm. Advantageously, the length of coherent integration can be increased at the expense of reducing the length of incoherent integration while keeping the total integration length the same, the net effect of which is an increase in signal detection sensitivity. The frequency drift hypothesis has any appropriate waveform; for example, approximately linear or exponential.

Abstract: A display system for a parachutist is provided based on navigation data and calculations of locations where the parachutist should steer the parachute to increase likelihood of reaching a target. A two-dimensional representation of a navigation funnel is displayed. The display may increase situational awareness by use of color to indicate preferred positions in the navigation funnel.

Abstract: The present invention relates to a navigation unit and base station used for determining location. A plurality of base stations are initialized to determine their location relative to each other. At the navigation unit, the time of arrival of at least one signal from each of the plurality of base stations is measured. From this, the location of the navigation unit relative to the plurality of base stations may be directly calculated using a closed solution. In one embodiment, a time of arrival technique is used and in another embodiment a time difference of arrival technique is used. Preferably an ultra-wide band frequency is utilized.

Abstract: A method and an apparatus for estimating behaviors of a vehicle are provided. At least two GPS antennas are located along a longitudinal axis of a vehicle so that speed vectors at the positions where the GPS antennas are located can be determined based on GPS signals received by the GPS antennas. The speed vectors are known to be estimated with high accuracy based on the GPS signals. The positions of the GPS antennas on the local coordinate system are estimated based on such highly accurate speed vectors, so that the estimated positions may also have high accuracy. Based on a line connecting these highly accurate positions of the GPS antennas, an inclination of the longitudinal axis of the vehicle is estimated. Use of the high-accuracy speed vectors enables high-accuracy estimation on the positions of the GPS antennas and the vehicle direction on the local coordinate system.

Abstract: Systems and methods for guiding a vehicle and vehicle sensor bias determination methods are disclosed. A method for guiding a vehicle includes a primary antenna of a primary survey-grade GNSS-receiver and a secondary antenna of a secondary GNSS-receiver mounted to the vehicle, which are at least temporarily receiving GNSS-signals of a global positioning system. A plurality of physical sensors mounted to the vehicle generate physical data indicative of respective measured physical parameters of at least part of the vehicle. The method includes de-biasing the physical data and applying a recursive statistical estimator, such as a Kalman filter, to the de-biased physical data and an output of the primary and secondary GNSS-receivers to determine a position and velocity of the vehicle.

Abstract: The present invention relates to an air navigation device with inertial sensor units and radio navigation receivers, and is characterized in that its radio navigation receivers are multiple-constellation receivers and in that their output data are hybridized with the data from the inertial sensor units. According to another feature of the invention, at least some of the inertial sensor units are of MEMS type.