Abstract: A method of mitigating filter inconsistency of a heading estimate in an inertial navigation system is provided.

Abstract: A method of mitigating filter inconsistency of a heading estimate in an inertial navigation system is provided.

Abstract: A method of mitigating filter inconsistency of a heading estimate in an inertial navigation system is provided.

Abstract: A method of mitigating filter inconsistency of a heading estimate in an inertial navigation system is provided.

Abstract: A method for data sharing between conditionally independent filters is provided. The method comprises initializing a plurality of conditionally independent filters operating in parallel, processing data measurements in each of the conditionally independent filters, sharing conditioning node estimates among the conditionally independent filters, merging the shared conditioning node estimates in each of the conditionally independent filters, and performing a conditional update in each of the conditionally independent filters.

Abstract: A system and method for motion-based adaptive frequency estimation of a Doppler sensor is provided. The system comprises a Doppler sensor configured to output a digitized Doppler data signal, and a Doppler velocity estimation module operatively coupled to the Doppler sensor to receive the Doppler data signal. An inertial navigation system is operatively coupled to the Doppler velocity estimation module, and one or more inertial sensors is operatively coupled to the inertial navigation system. The inertial sensors are configured to transmit inertial navigation data to the inertial navigation system. The Doppler velocity estimation module calculates a speed or velocity estimate based on the Doppler data signal and the inertial navigation data. The speed or velocity estimate is then transmitted to the inertial navigation system.

Abstract: Embodiments of the present invention provide improved systems and methods for estimating N-dimensional parameters while sensing fewer than N dimensions. In one embodiment a navigational system comprises a processor and an inertial measurement unit (IMU) that provides an output to the processor, the processor providing a navigation solution based on the output of the IMU, wherein the navigation solution includes a calculation of an n-dimensional parameter. Further, the navigational system includes at most two sensors that provide an output to the processor, wherein the processor computes an estimate of an n-dimensional parameter from the output of the at most two sensors for bounding errors in the n-dimensional parameter as calculated by the processor when the trajectory measured by the IMU satisfies movement requirements, wherein “n” is greater than the number of the at most two sensors.

Abstract: A method for data sharing between conditionally independent filters is provided. The method comprises initializing a plurality of conditionally independent filters operating in parallel, processing data measurements in each of the conditionally independent filters, sharing conditioning node estimates among the conditionally independent filters, merging the shared conditioning node estimates in each of the conditionally independent filters, and performing a conditional update in each of the conditionally independent filters.

Abstract: A method for collaborative navigation comprises initializing a conditionally independent filter on a local platform, propagating the conditionally independent filter forward in time, and when a local measurement has been made, updating the conditionally independent filter with the local measurement. When a common measurement has been made, the conditionally independent filter is updated with the common measurement, and a determination is made whether a remote conditioning node has arrived from a remote platform. If a remote conditioning node has arrived, a determination is made whether the remote conditioning node needs to be fused with a local conditioning node of the conditionally independent filter. If the remote conditioning node needs to be fused, a node-to-node fusion is performed in the conditionally independent filter to merge the remote conditioning node with the local conditioning node to produce a merged conditioning node.

Abstract: A system and method for motion-based adaptive frequency estimation of a Doppler sensor is provided. The system comprises a Doppler sensor configured to output a digitized Doppler data signal, and a Doppler velocity estimation module operatively coupled to the Doppler sensor to receive the Doppler data signal. An inertial navigation system is operatively coupled to the Doppler velocity estimation module, and one or more inertial sensors is operatively coupled to the inertial navigation system. The inertial sensors are configured to transmit inertial navigation data to the inertial navigation system. The Doppler velocity estimation module calculates a speed or velocity estimate based on the Doppler data signal and the inertial navigation data. The speed or velocity estimate is then transmitted to the inertial navigation system.

Abstract: Systems and methods for differential altitude estimation utilizing spatial interpolation of pressure sensor data are provided. In one embodiment, a method for mobile navigation comprises: measuring a horizontal location of a mobile navigation unit to generate two-dimensional horizontal coordinate data; measuring a barometric pressure at the mobile navigation unit with a sensor to obtain local pressure data; processing information representative of pressure data derived from a network of a plurality reference stations to obtain a correction factor; performing a calculation using the two-dimensional horizontal coordinate data, the local pressure data, and the correction factor to calculate an altitude coordinate; and determining an altitude of the mobile navigation unit from the altitude coordinate.

Abstract: Systems and methods for differential altitude estimation utilizing spatial interpolation of pressure sensor data are provided. In one embodiment, a method for mobile navigation comprises: measuring a horizontal location of a mobile navigation unit to generate two-dimensional horizontal coordinate data; measuring a barometric pressure at the mobile navigation unit with a sensor to obtain local pressure data; processing information representative of pressure data derived from a network of a plurality reference stations to obtain a correction factor; performing a calculation using the two-dimensional horizontal coordinate data, the local pressure data, and the correction factor to calculate an altitude coordinate; and determining an altitude of the mobile navigation unit from the altitude coordinate.

Abstract: Embodiments of the present invention provide improved systems and methods for estimating N-dimensional parameters while sensing fewer than N dimensions. In one embodiment a navigational system comprises a processor and an inertial measurement unit (IMU) that provides an output to the processor, the processor providing a navigation solution based on the output of the IMU, wherein the navigation solution includes a calculation of an n-dimensional parameter. Further, the navigational system includes at most two sensors that provide an output to the processor, wherein the processor computes an estimate of an n-dimensional parameter from the output of the at most two sensors for bounding errors in the n-dimensional parameter as calculated by the processor when the trajectory measured by the IMU satisfies movement requirements, wherein “n” is greater than the number of the at most two sensors.