Abstract: Systems and methods for use in navigating aircraft are provided. The systems can use Geometry Redundant Almost Fixed Solutions (GRAFS) or Geometry Extra Redundant Almost Fixed Solutions (GERAFS) to compute high confidence error bounds for a heading angle estimate or pitch angle derived using signals received on at least two antennas.

Abstract: A system and method established and maintains precision relative position, navigation, and timing (PNT) across a network of at least four mutually connected mobile platforms. In embodiments, a key (e.g., advantaged, absolute positioning capable) node of the network determines its pressure altitude and inertial state relative to its platform reference frame and receives inertial state and pressure altitude data from each neighboring node (in exchange for its own) to estimate the relative position and orientation of each neighbor node in its platform frame. The key node performs ranging to each neighboring node, and the neighboring nodes additionally range between each other and exchange ranging data with the key node. By correcting position and orientation estimates via ranging data, the key node determines and maintains extended relative PNT (e.g., in GPS-denied areas), which relative PNT solution is distributed across all network nodes.

Abstract: A system detects slowly diverging navigational signals by updating the current location from purely internal navigational aids for a period of time. The updated location compared to a continuously corrected current location; if the comparison indicates a deviation outside an expected boundary threshold, the external source is excluded from further measurements. Multiple monitoring elements may be staggered such that one or more monitoring elements are always sequestered for future comparisons. The multiple monitoring elements may monitor different external sources with different weights to identify a specific faulty external source.

Abstract: The method and corresponding system for autonomous operation may include implementing a safe system controller for autonomous vehicles to receive a set of event data for an event encountered during operation of a vehicle from a status engine of the vehicle; analyze the received set of event data; determine a vehicle system state based on the analyzed set of event data; receive a set of automation operational parameters from an automation engine of the vehicle; receive a set of autonomy operational parameters from an autonomy engine of the vehicle; determine a response to the event from the set of automation operational parameters and the set of autonomy operational parameters based on the determined vehicle system state; and provide the determined response to the automation engine and the autonomy engine to adjust an operational parameter of the vehicle.

Abstract: Systems and methods for use in navigating aircraft are provided. The systems can use Geometry Redundant Almost Fixed Solutions (GRAFS) or Geometry Extra Redundant Almost Fixed Solutions (GERAFS) to compute high confidence error bounds for a heading angle estimate or pitch angle derived using signals received on at least two antennas.

Abstract: A system and related method for validating satellite-based navigation data determines an estimated altitude or position solution based on GPS altitude or position data adjusted with inertial altitude or position data integrated with barometric altitude data corrected for air temperature and latitude. The system may include a vertical monitor for validating the GPS altitude data by comparing the weighted, limited, and integrated estimated altitude solution to the GPS altitude data. The integrated altitude solution may compensate for vertical speed offset. The system may provide secondary altitude monitoring by comparing radar altimeter data to local object data to verify obstacle clearance height. The system may include a lateral monitor for validating GPS lateral position data based on weighting and limiting of altitude sources controlled by a height above threshold estimate from the vertical monitor. Validity information may be presented to the pilot or autopilot.

Abstract: A system includes a first solution engine, second solution engine, output voter engine, and output modification engine. The first solution engine receives first sensor data associated with a first error rate, and determines at least one first flight parameter based on the first sensor data. The second solution engine receives the first sensor data and second sensor data associated with a second error rate, and determines at least one second flight parameter based on the first and second sensor data. The output voter engine determines a difference between the flight parameters, compares the difference to a first threshold, and generates an output including the at least one first flight parameter or the at least one second flight parameter. The output modification engine receives the output from the output voter engine, modifies a rate of change of the output to be less than a second threshold, and transmits the modified output.

Abstract: Devices, systems, and methods for determining azimuth, elevation, or object position relative to a baseline using an integrated sighting device. The integrated sighting device includes a GPS receiver, an inertial measurement unit (IMU), an optical aperture, a microcomputer, and a handheld housing. The integrated sighting device, during transit from a reference position to a sighting position, determines a first angle between the sighting position and the reference position based on carrier phase input received during the transit. Orientation input is received from the IMU at the sighting position as the integrated sighting device is aimed and sighted along a line of sight to the reference position. The baseline is generated based on a second angle of the orientation input correlating with the first angle. The baseline is used as a reference for determining azimuth, elevation, or position of other objects or devices.

Abstract: Systems and a related method for internally monitored navigation replace one or more inertial reference units (IRU) of an aircraft navigation system with GNSS-assisted multi-mode receivers (MMR) including dual-antenna receivers. Each MMR may validate inertial position data generated by a remaining IRU by detecting drift errors in the inertial position data or latent faults in the IRU. The system may include, in place of one or more IRUs, attitude heading and reference systems (AHRS) incorporating lower-grade high-performance inertial sensors. Internal monitoring of the remaining IRUs or the inertial position data generated thereby may alternatively be carried out by the AHRS. Based on internal monitoring by the MMRs and/or AHRS, user display and flight control systems of an aircraft can exclude a faulty IRU, preventing the use of position solutions incorporating erroneous inertial data.

Abstract: Systems for multi-mode receiver (MMR)-based inertial integration of position solutions replace expensive IRUs with lower-grade but high-performance inertial sensors and GNSS-assisted MMRs, collecting inertial position data indicative of an aircraft position and integrating the inertial data with georeferenced position data within the MMRs. The inertial sensors may include microelectromechanical attitude and heading reference systems capable of generating coasted position solutions based on secondary inertial data and integrated with georeferenced data when it is available. The coasted position solutions may be used as a standby alternative to primary integrated solutions, or serve as an additional primary position solution.

Abstract: Systems and related methods for simultaneous high precision synchronization and syntonization of multiple sensors or clocks utilize a precision estimator that receives clock signals and time mark signals from both sensors (a reference sensor and a clock to be measured against the reference sensor). A precision time and frequency estimator determines a time offset, frequency offset, and phase offset of the measured sensor relative to the reference sensor. Associated systems can additionally determine the propagation delay between two remote subsystems connected by a communications channel. The communications channel may be a bidirectional duplexed or multiplexed channel allowing for mutual exchange of timing information along a single non-dedicated cable between sensors. Sensors may be synchronized to within 10 ps of each other without the need for THz clocks or fiber-optic cabling.

Abstract: An airborne navigation system that uses Doppler information from an on-board weather radar to improve the system's accuracy and/or fault tolerance. The system can determine a drift angle and ground speed from Doppler information associated with radar returns from the Earth's surface. Alternatively, the system can be configured to determine heading angle using the drift angle and a track angle received from another sensor.

Abstract: A satellite navigation signal receiver connected to a legacy satellite navigation system receives a plurality of satellite signals. The receiver selects a subset of the plurality of signals and uses all available data from all of the signals to correct any errors in the subset of signals or otherwise increase the precision of the subset of signals. Alternatively, the receiver uses all of the available data in the plurality of signals to simulate idealized satellite signals that the legacy satellite navigation system uses to derive a location.

Abstract: A system, device, and method for generating an RNP-scaled waypoint symbology presentable to a pilot are disclosed. The symbology generating system may include a source of source of navigation data, a symbology generator (SG), and a presentation system. The SG may be configured to acquire navigation data representative of one or more distance measurements of an area navigation system or a required navigation performance system; and generate presentation data as a function of each distance measurement. The presentation data could be representative of waypoint symbology presentable to a viewer. In some embodiments, the waypoint symbology may be comprised of a two-dimensional object or a three-dimensional object having a plurality of shapes centered on a reference line, where a size of a first shape may be scaled to a first distance measurement, and a size of a second shape may be scaled to a second distance measurement.

Abstract: Present novel and non-trivial system, device, and method for generating geographic position are disclosed. A processor receives navigation data representative of geographic position from an external source such as a global positioning system (“GPS”); receives navigation data representative of measurements of angular and linear motions from an internal source of navigation data such as an inertial measurement unit (“IMU”); and determines and generates navigation data representative of geographic position responsive to such determination. The generation of navigation data could be based upon internal source navigation data and an estimate of error of geographic position, where the estimate of error is based upon a delay of the external-sourced navigation data and a delayed output from one of the internal sources (e.g., delayed output of an IMU).

Abstract: Systems and methods for mitigating multipath effects on precision PNT estimation are disclosed. Frequency-domain windowing techniques are disclosed and utilized to mitigate multipath effects on precision PNT estimation for systems employing coherent communication signals. More specifically, to mitigate multipath effects an input signal, the input signal may be channelized into a plurality of carrier-specific signals, and each carrier-specific signal may be correlated against a reference signal to produce a corresponding carrier-specific correlation result. A window function may be applied to the carrier-specific correlation results for the plurality of carriers to produce a set of carrier-specific weighted correlation results. The set of carrier-specific weighted correlation results may be integrated to produce an integrated correlation output, which may then be utilized to facilitate PNT estimation.

Abstract: Present novel and non-trivial systems and methods for validating navigation data are disclosed. A processor receives navigation data from an external source such as a global positioning system (“GPS”); receives navigation data from a second source comprised of multiple sources; determines the validity of the GPS navigation data; and alerts the pilot if validity of the data falls outside a limit. In an embodiment related to lateral information (i.e., geographic position) data, the second navigation data is comprised of both GPS data and data provided from an internal source. In an embodiment related to altitude information data, the second navigation data is comprised of both GPS data and data provided by multiple internal sources.

Abstract: A method of determining the ground speed or drift angle of an aircraft is described. It is determined whether or not a weather threshold has been met based on returns of a radar beam which is pulse compressed in a first scan. If the weather threshold is determined to have not been met, a ground speed or drift angle of the aircraft is determined based on Doppler processing of radar beam returns of a radar beam in a second scan. If the weather threshold has been met, a bottom radar beam is directed lower to the ground, and a ground speed or drift angle of the aircraft is determined based on Doppler processing returns of the bottom radar beam directed lower to the ground. A corresponding radar system is also described.

Abstract: A position determining voting system that uses Doppler information from an on-board weather radar to improve the system's accuracy and/or fault tolerance includes a comparison function and an error integration function. The comparison function is used to monitor the independent position sources for correct operation, comparing and identifying a position source that should not be used based on its relative error compared with the other position sources and their characteristics. The integration function provides corrections to relative position sources by integrating the data from multiple absolute position sources when they are mutually consistent.

Abstract: Present novel and non-trivial system, device, and method for generating altitude data and/or height data are disclosed. A processor receives navigation data from an external source such as a global positioning system (“GPS”); receives navigation data from multiple internal sources; receives object data representative of terrain or surface feature elevation; determines an instant measurement of aircraft altitude as a function of these inputs; and generates aircraft altitude data responsive to such determination. In an additional embodiment, the processor receives reference point data representative of the elevation of the stationary reference point (e.g., a landing threshold point); determines an instant measurement of aircraft height as a function of this input and the instant measurement of aircraft altitude; and generates aircraft height data responsive to such determination.