Abstract: Systems and methods for fault detection, exclusion, isolation, and re-configuration of navigation sensors using an abstraction layer are provided. In certain embodiments, a system includes a plurality of sensors that provide redundant sensor measurements, wherein redundancy of the redundant sensor measurements is achieved based on an independence between measurements from different physical sensor units in the plurality of sensors. The system additionally includes a fusion function configured to receive the redundant sensor measurements from each sensor in the plurality of sensors and calculate fused navigation parameters. Further, the system includes an abstraction layer that calculates an estimated state based on the fused navigation parameters, wherein the estimated state comprises safety assessment information for the fused navigation parameters and the fused navigation parameters.

Abstract: Techniques for detecting GNSS spoofing using inertial mixing data are disclosed. One or more navigation parameters are determined by at least one GNSS receiver and a plurality of IRS from at least two periods of time. The navigation parameters from the GNSS receiver(s) and the IRS are compared at each time period, and the difference(s) between the compared navigation parameters are further compared to generate at least one differential value. A system can detect GNSS spoofing by comparing the at least one differential value to a suitable threshold. In one aspect each IRS navigation parameter is compared with a corresponding GNSS navigation parameter, wherein the plurality of differential values is mixed before threshold comparison. In another aspect, each IRS navigation parameter is mixed before comparison with a GNSS navigation parameter, and the resulting differential value is then compared against a threshold.

Abstract: A method to assure integrity of integrated certified and non-certified sensors or systems comprises calculating a certified main solution filter within a first software thread in a certified partition; calculating certified sub-solution filters, and sub-sub-solution filters within the first software thread; calculating a non-certified main solution filter within a second software thread in a non-certified partition; if applicable, reusing the certified main solution filter as a non-certified sub-solution filter, and reusing the certified sub-solution filters, as non-certified sub-sub-solution filters; calculating non-certified sub-solution filters, and sub-sub-solution filters, within the second software thread; based on the certified filters, determining protection limits of the certified partition, and/or providing execution of fault detection and exclusion; based on the non-certified filters, determining protection limits of the non-certified partition, and/or providing execution of fault detection and exc

Abstract: A method for determining fleet wide integrity comprises forming a user measurement block for each user in a fleet network, the user measurement block comprising: navigation measurements received by the user, relative user measurements received by the user from other users, and navigation state and integrity solutions. The user measurement block is signed and sent to all other users for validation. Each user executes a numerical process to determine a navigation state and integrity of all users. A fleet state block is formed comprising: a header including a hash of last valid fleet state block header, a nonce-proof of work, and a root hash of Merkle tree; and a data block including measurement, state, and integrity information of the fleet. The fleet state block is sent to all other users for validation. If the fleet state block passes validation, the user forms a chain of fleet state blocks.

Abstract: Techniques for detecting GNSS spoofing using inertial mixing data are disclosed. One or more navigation parameters are determined by at least one GNSS receiver and a plurality of IRS from at least two periods of time. The navigation parameters from the GNSS receiver(s) and the IRS are compared at each time period, and the difference(s) between the compared navigation parameters are further compared to generate at least one differential value. A system can detect GNSS spoofing by comparing the at least one differential value to a suitable threshold. In one aspect each IRS navigation parameter is compared with a corresponding GNSS navigation parameter, wherein the plurality of differential values is mixed before threshold comparison. In another aspect, each IRS navigation parameter is mixed before comparison with a GNSS navigation parameter, and the resulting differential value is then compared against a threshold.

Abstract: Systems and methods for fault detection, exclusion, isolation, and re-configuration of navigation sensors using an abstraction layer are provided. In certain embodiments, a system includes a plurality of sensors that provide redundant sensor measurements, wherein redundancy of the redundant sensor measurements is achieved based on an independence between measurements from different physical sensor units in the plurality of sensors. The system additionally includes a fusion function configured to receive the redundant sensor measurements from each sensor in the plurality of sensors and calculate fused navigation parameters. Further, the system includes an abstraction layer that calculates an estimated state based on the fused navigation parameters, wherein the estimated state comprises safety assessment information for the fused navigation parameters and the fused navigation parameters.

Abstract: A method for computing and applying alternative uncertainty limits is provided. The method includes generating a main solution from a plurality of received measurement signals. A solution separation is applied using a filter bank to generate sub-solutions from the received plurality of measurement signals. Each sub-solution uses all of the measurement signals from the plurality of measurement signals except one measurement signal to generate the associated sub-solution. Each sub-solution excludes a different measurement signal. One sub-solution is selected as fault free. A difference between the main solution and the selected sub-solution is determined. The determined difference is added to a rare normal protection limit to create a solution with improved integrity bounding. The solution with improved integrity bounding is then implemented.

Abstract: Methods, apparatuses and systems for use of a magnetometer calibration (MAG-CAL) application to calibrate a magnetometer while an aircraft is in-flight including: generating a MAG-CAL calculated pattern based on a set of aircraft parameters for the in-air magnetometer calibration, the set of aircraft parameters at least comprise: speed, bank angle, altitude and position of the aircraft; generating a set of waypoints that define a calibration flight path corresponding to the MAG-CAL calculated pattern; Configuring the calibration flight path of the MAG-CAL calculated pattern to be part of the original flight path of the in-flight aircraft to enable the aircraft while flying the original flight to proceed in part on the calibration flight path corresponding to the MAG-CAL calculated pattern; and enabling the aircraft to deviate while in-flight from the original flight path to the calibration flight path to enable a sufficient level of calibration for accurate magnetometer operation.

Abstract: A method to assure integrity of integrated certified and non-certified sensors or systems comprises calculating a certified main solution filter within a first software thread in a certified partition; calculating certified sub-solution filters, and sub-sub-solution filters within the first software thread; calculating a non-certified main solution filter within a second software thread in a non-certified partition; if applicable, reusing the certified main solution filter as a non-certified sub-solution filter, and reusing the certified sub-solution filters, as non-certified sub-sub-solution filters; calculating non-certified sub-solution filters, and sub-sub-solution filters, within the second software thread; based on the certified filters, determining protection limits of the certified partition, and/or providing execution of fault detection and exclusion; based on the non-certified filters, determining protection limits of the non-certified partition, and/or providing execution of fault detection and exc

Abstract: A vehicle disturbance and isolation detection system is provided. The system includes at least one measurement sensor that is configured to generate measurement signals, at least one filter that is used to sort disturbance causes in the measured signals by frequencies, at least one controller that is used to compare the sorted signal to at least one threshold to determine if an event has occurred, a memory to store at least operating instructions for the at least one controller, a controller that is in communication with the memory and a communication system that is in communication with the at least one controller. The communication system is configured to transmit determined events to a remote location.

Abstract: A method of inspecting a navigation aid, the method comprising: receiving navigation data relating to the navigation aid from a plurality of vehicles; statistically analyzing the received navigation data; determining the accuracy of the navigation aid based on the statistically analyzed navigation data; and calibrating the navigational aid based on the determined accuracy of the navigation aid.

Abstract: A method for computing and applying alternative uncertainty limits is provided. The method includes generating a main solution from a plurality of received measurement signals. A solution separation is applied using a filter bank to generate sub-solutions from the received plurality of measurement signals. Each sub-solution uses all of the measurement signals from the plurality of measurement signals except one measurement signal to generate the associated sub-solution. Each sub-solution excludes a different measurement signal. One sub-solution is selected as fault free. A difference between the main solution and the selected sub-solution is determined. The determined difference is added to a rare normal protection limit to create a solution with improved integrity bounding. The solution with improved integrity bounding is then implemented.

Abstract: Methods, apparatuses and systems for use of a magnetometer calibration (MAG-CAL) application to calibrate a magnetometer while an aircraft is in-flight including: generating a MAG-CAL calculated pattern based on a set of aircraft parameters for the in-air magnetometer calibration, the set of aircraft parameters at least comprise: speed, bank angle, altitude and position of the aircraft; generating a set of waypoints that define a calibration flight path corresponding to the MAG-CAL calculated pattern; Configuring the calibration flight path of the MAG-CAL calculated pattern to be part of the original flight path of the in-flight aircraft to enable the aircraft while flying the original flight to proceed in part on the calibration flight path corresponding to the MAG-CAL calculated pattern; and enabling the aircraft to deviate while in-flight from the original flight path to the calibration flight path to enable a sufficient level of calibration for accurate magnetometer operation.

Abstract: A method of inspecting a navigation aid, the method comprising: receiving navigation data relating to the navigation aid from a plurality of vehicles; statistically analyzing the received navigation data; determining the accuracy of the navigation aid based on the statistically analyzed navigation data; and calibrating the navigational aid based on the determined accuracy of the navigation aid.

Abstract: Systems and methods for isolating attitude failures are provided. In one embodiment, an attitude integrity and display system comprises a display system comprising a primary system displaying a first attitude solution and a standby system displaying a second attitude solution; an attitude integrity system generating an attitude integrity (AI) solution calculated from measurements from an attitude solution data source, the AI solution comprising an aircraft roll and pitch, the data source providing data independent from any data generated by inertial sensor flight instruments and not displayed on either the primary or the standby systems; and an attitude monitor that compares the first solution against the second solution. When the first solution deviates from the second solution by more than a threshold, the monitor identifies on the display system which of either the first or the second solution is failed based on which has a greater deviation from the AI solution.

Abstract: Systems and methods for attitude fault detection based on integrated GNSS/inertial hybrid filter residuals are provided. In one embodiment, a fault detection system for aircraft attitude measurement system comprises: a sensor monitor coupled to a first inertial measurement unit, the sensor monitor comprising: a navigation error model for the first inertial measurement unit, the model configured to model a plurality of error states including at least an attitude error state vector, an velocity error state vector, and a position error state vector determined from data generated by the first inertial measurement unit; and a propagator-estimator configured to propagate and update error states based on GNSS data; and a residual evaluator configured to input measurement error residual values generated by the propagator-estimator, wherein the residual evaluator outputs an alert signal when the measurement error residual values exceed a threshold.

Abstract: Systems and methods for attitude fault detection based on integrated GNSS/inertial hybrid filter residuals are provided. In one embodiment, a fault detection system for aircraft attitude measurement system comprises: a sensor monitor coupled to a first inertial measurement unit, the sensor monitor comprising: a navigation error model for the first inertial measurement unit, the model configured to model a plurality of error states including at least an attitude error state vector, an velocity error state vector, and a position error state vector determined from data generated by the first inertial measurement unit; and a propagator-estimator configured to propagate and update error states based on GNSS data; and a residual evaluator configured to input measurement error residual values generated by the propagator-estimator, wherein the residual evaluator outputs an alert signal when the measurement error residual values exceed a threshold.

Abstract: A method to calibrate at least one lever arm between at least one respective global positioning system (GPS) antenna/receiver and a communicatively coupled inertial navigation system is provided. The method includes receiving signals from the at least one GPS antenna/receiver at the inertial navigation system communicatively coupled to a Kalman filter; and estimating, in the Kalman filter, at least one fixed lever arm component while accounting for a bending motion of the lever arm based on the received signals.

Abstract: Systems and methods for isolating attitude failures are provided. In one embodiment, an attitude integrity and display system comprises a display system comprising a primary system displaying a first attitude solution and a standby system displaying a second attitude solution; an attitude integrity system generating an attitude integrity (AI) solution calculated from measurements from an attitude solution data source, the AI solution comprising an aircraft roll and pitch, the data source providing data independent from any data generated by inertial sensor flight instruments and not displayed on either the primary or the standby systems; and an attitude monitor that compares the first solution against the second solution. When the first solution deviates from the second solution by more than a threshold, the monitor identifies on the display system which of either the first or the second solution is failed based on which has a greater deviation from the AI solution.

Abstract: A method to calibrate at least one lever arm between at least one respective global positioning system (GPS) antenna/receiver and a communicatively coupled inertial navigation system is provided. The method includes receiving signals from the at least one GPS antenna/receiver at the inertial navigation system communicatively coupled to a Kalman filter; and estimating, in the Kalman filter, at least one fixed lever arm component while accounting for a bending motion of the lever arm based on the received signals.