Systems and methods for automated unmanned aerial vehicle recognition. A multiplicity of receivers captures RF data and transmits the RF data to at least one node device. The at least one node device comprises a signal processing engine, a detection engine, a classification engine, and a direction finding engine. The at least one node device is configured with an artificial intelligence algorithm. The detection engine and classification engine are trained to detect and classify signals from unmanned vehicles and their controllers based on processed data from the signal processing engine. The direction finding engine is operable to provide lines of bearing for detected unmanned vehicles.

A receiver circuit is disclosed. The receiver circuit includes a receiver antenna or a receiver antenna arrays oriented at a receiver orientation angle and configured to receive a plurality of RF signals transmitted from a transmitter circuit including a transmit antenna or a transmit antenna array oriented at a transmitter orientation angle. A controller A) calculates first and second AoAs based on a first signal at a first receiver antenna array, and calculates third and fourth AoAs based on a second signal at a second receiver antenna array, and/or B) calculates first and second AoDs based on a third signal from a first transmit antenna array, and calculates third and fourth AoDs based on a fourth signal from a second transmit antenna array. The controller also determines which of the first and second AoAs is correct, and/or determines which of the first and second AoDs is correct.

Embodiments of the disclosure are drawn to apparatuses, systems, and methods for radio direction finding with an iterative ambiguity resolution algorithm. An antenna array may receive an emitted signal. Two or more phase shifts in the received emitted signal may be determined between two or more pairs of antennas of the antenna array. A set of possible expected phase shifts may be generated from at least two of the measured phase shift. To determine the proper one of the set of expected phase shifts, a set of initial guesses for parameters of a fitting equation may be generated and then each may be optimized to determine optimized fitting parameters. From these optimized fitting parameters a direction of arrival of the emitted signal may be determined.

Embodiments of the disclosure are drawn to apparatuses, systems, and methods for radio direction finding with an iterative ambiguity resolution algorithm. An antenna array may receive an emitted signal. Two or more phase shifts in the received emitted signal may be determined between two or more pairs of antennas of the antenna array. A set of possible expected phase shifts may be generated from at least two of the measured phase shift. To determine the proper one of the set of expected phase shifts, a set of initial guesses for parameters of a fitting equation may be generated and then each may be optimized to determine optimized fitting parameters. From these optimized fitting parameters a direction of arrival of the emitted signal may be determined.

A transceiver configured to: determine a reference frequency offset relative to a second transceiver based on double sided ranging; correct first and second portions of a packet received from a respective first and second antenna; and determine an angle of arrival of the packet based on corrected first and second portions and the reference frequency offset.

[FIG. 10]

A computer system for angle of arrival estimation receives one or more snapshots from a circular array of antennas. The computer system processes the one or more snapshots for amplitude and/or phase-based direction finding using two cascaded algorithms. The first algorithm of the two cascaded algorithms is configured to identify a target subregion from which a signal arrives. The second algorithm of the two cascaded algorithms is configured to identify a direction of the signal within the target subregion.

A computer system for angle of arrival estimation receives one or more snapshots from a circular array of antennas. The computer system processes the one or more snapshots for amplitude and/or phase-based direction finding using two cascaded algorithms. The first algorithm of the two cascaded algorithms is configured to identify a target subregion from which a signal arrives. The second algorithm of the two cascaded algorithms is configured to identify a direction of the signal within the target subregion.

Signals are received from antenna elements in an antenna array, and respective phase shifts are applied to the received signals. The respective phase shifts are relative to a channel phase shift associated with each antenna element, and correspond to side angles from a current antenna beam direction of the antenna array. Control signals based on the phase shifted signals are generated to control the channel phase shifts, to provide beamforming tracking.

A method for calibrating spatial errors induced by phase biases having a detrimental effect on the measurements of phase differences of radio signals received by three unaligned receiving antennas of a vehicle. An inter-satellite angular deviation of a pair of satellites is estimated in two different ways: on the basis of the respective positions of the vehicle and of the satellites to obtain a theoretical inter-satellite angular deviation; and on the basis of the respective directions of incidence of the satellites relative to the vehicle, which are determined from phase measurements, to obtain an estimated inter-satellite angular deviation. The space errors are estimated on the basis of said theoretical and estimated inter-satellite angular deviations. Also, a method and system for estimating the attitude of a vehicle, in particular a spacecraft.

A method for calibrating spatial errors induced by phase biases having a detrimental effect on the measurements of phase differences of radio signals received by three unaligned receiving antennas of a vehicle. An inter-satellite angular deviation of a pair of satellites is estimated in two different ways: on the basis of the respective positions of the vehicle and of the satellites to obtain a theoretical inter-satellite angular deviation; and on the basis of the respective directions of incidence of the satellites relative to the vehicle, which are determined from phase measurements, to obtain an estimated inter-satellite angular deviation. The space errors are estimated on the basis of said theoretical and estimated inter-satellite angular deviations. Also, a method and system for estimating the attitude of a vehicle, in particular a spacecraft.