Machine learning techniques are used, in one embodiment, to mitigate multipath in an L5 GNSS receiver. In one embodiment, training data is generated to provide ground truth data for excess path length (EPL) corrections for a set of received GNSS signals. A system extracts features from the set of received GNSS signals and uses the extracted features and the ground truth data to train a set of one or more neural networks that can produce EPL corrections for pseudorange measurements. The trained set of one or more neural networks can be deployed in GNSS receivers and used in the GNSS receivers to correct pseudorange measurements using EPL corrections provided by the trained set of neural networks.

Machine learning techniques are used, in one embodiment, to mitigate multipath in an L5 GNSS receiver. In one embodiment, training data is generated to provide ground truth data for excess path length (EPL) corrections for a set of received GNSS signals. A system extracts features from the set of received GNSS signals and uses the extracted features and the ground truth data to train a set of one or more neural networks that can produce EPL corrections for pseudorange measurements. The trained set of one or more neural networks can be deployed in GNSS receivers and used in the GNSS receivers to correct pseudorange measurements using EPL corrections provided by the trained set of neural networks.

A system, non-transitory computer readable medium, and method include entering redundant oscillators and a cascaded oscillator of a spoofing resistant system into an initialization state. All but one of the redundant oscillators are disciplined to a time-and-frequency external input into normal disciplining state with the remaining one of the redundant oscillators in a holdover state. When all but one of the redundant oscillators have reached the normal disciplining state, placing all but one of the redundant oscillators into the holdover state, disciplining the remaining one of the redundant oscillators to the time and frequency external input, and disciplining the cascaded oscillator to one of the all but one of the redundant oscillators now in the holdover state. When the remaining one of the redundant oscillators and the cascaded oscillator have reached the normal disciplining state, transitioning from an initialization stage to a steady state management stage.

A system, non-transitory computer readable medium, and method include entering redundant oscillators and a cascaded oscillator of a spoofing resistant system into an initialization state. All but one of the redundant oscillators are disciplined to a time-and-frequency external input into normal disciplining state with the remaining one of the redundant oscillators in a holdover state. When all but one of the redundant oscillators have reached the normal disciplining state, placing all but one of the redundant oscillators into the holdover state, disciplining the remaining one of the redundant oscillators to the time and frequency external input, and disciplining the cascaded oscillator to one of the all but one of the redundant oscillators now in the holdover state. When the remaining one of the redundant oscillators and the cascaded oscillator have reached the normal disciplining state, transitioning from an initialization stage to a steady state management stage.

Systems, devices, methods, and computer-readable media for improved location determination of an orbiting device. A method can include receiving, at a transceiver of a device, measurement data from a monitor device, the measurement data representative of a physical state of a mobile object, filtering, using a first of a plurality of first filters of the device, the measurement data based on a character parameter of a state transition matrix representative of the physical state resulting in filtered measurement data, filtering, using a Kalman filter, the filtered measurement data resulting in further filtered measurement data, and providing, by the transceiver, the further filtered measurement data.

Systems, devices, methods, and computer-readable media for improved location determination of an orbiting device. A method can include receiving, at a transceiver of a device, measurement data from a monitor device, the measurement data representative of a physical state of a mobile object, filtering, using a first of a plurality of first filters of the device, the measurement data based on a character parameter of a state transition matrix representative of the physical state resulting in filtered measurement data, filtering, using a Kalman filter, the filtered measurement data resulting in further filtered measurement data, and providing, by the transceiver, the further filtered measurement data.

An anechoic chamber and test system that is adapted for installation in or to a vehicle. The chamber includes an outer structure that is durable enough to withstand the effects of transportation. The anechoic chamber and test system may also include an inner faraday shield, a transmission antenna, and a controller that can introduce GNSS, alternative navigation signals, jamming, or spoofing signals into the anechoic chamber along with vehicle sensor signals. The controller is adapted to monitor a GNSS system's ability to resist the jamming or spoofing signals using, at least in part, the vehicle sensor signals.

A system of architecture, apparatus and calibration method is invented for high-power flexible-polarization payload for satellite communications. The system comprises onboard phase-tracked apparatus, flexible polarization mechanism, and in-orbit calibration method. The power combining and polarization performance of the phase-tracked payload is monitored on ground by measuring the cross-polarization discrimination (XPD) and/or axial ratio (AR). The high performance over the life is achieved by optimization of the XPD or AR on ground and adjusting complex gain of the transponders. The high-power flexible-polarization in-orbit-calibration payload may be applied but not limited to UHF, L, S, C, X, Ku and Ka-band high power satellite systems.

FAST provides a method of “bootstrapping” a pseudo-range (PR) stage and one or more carrier-phase (CP) stages to quickly produce a highly accurate, high integrity receiver-to-receiver lever arm survey based on differential GNSS processing. The lever arm estimates of a previous stage are used to resolve the carrier phase ambiguities of the next stage. The method can be integrated with the warm-up of the integrity monitors to reduce the entire survey and warm-up startup time to 90 minutes or less, which is critical for mobile and make shift and precision approach and (automated) landing operations.

FAST provides a method of “bootstrapping” a pseudo-range (PR) stage and one or more carrier-phase (CP) stages to quickly produce a highly accurate, high integrity receiver-to-receiver lever arm survey based on differential GNSS processing. The lever arm estimates of a previous stage are used to resolve the carrier phase ambiguities of the next stage. The method can be integrated with the warm-up of the integrity monitors to reduce the entire survey and warm-up startup time to 90 minutes or less, which is critical for mobile and make shift and precision approach and (automated) landing operations.