A direction detection device for detecting a received-wave arrival direction of a received wave, and includes: antennas for receiving the received wave; an intensity difference imparting unit that imparts intensity differences different depending on the received-wave arrival direction to intensities of the received wave; a storage unit that stores an intensity difference table an which the intensity difference between two of the antennas is associated with the received-wave arrival direction, for each combination of any two of the antennas; a detector that detects the intensity difference between the two antennas of the received wave; an extractor that extracts, from the intensity difference table, received-wave arrival directions corresponding to the intensity difference detected by the detector, for each combination; and a comparator that compares the received-wave arrival directions extracted by the extractor between the combinations of the antennas to acquire a matched received-wave arrival direction as a detection result.

A direction of arrival estimation apparatus includes at least first and second sub-arrays to receive a reflected wave of a transmission waveform from a target; first and second phasing parts that perform phasing of reception signals at the first and second sub-arrays to generate first and second sub-array beams; an arrival time difference calculation part that calculates first and second correlations of the reception signals of the first and second sub-array beams at first and second time points to find an arrival time difference between times of the reflected wave arriving at the first and second sub-arrays, based on a result of a predetermined operation on the first and second correlations and a time difference between the first time point and the second time point; and a direction of arrival calculation part that finds a direction of arrival of the target based on the arrival time difference.

An active biconical antenna and a receive array comprising a combination of active biconical and Vivaldi antennas. In one configuration, the active biconical antenna includes upper and lower cones. Each cone has a respective truncated apex. First and second feed points are respectively connected to the truncated apexes of the upper and lower cones and to first and second conductors. The active biconical antenna further includes a buffer amplifier having respective input terminals connected to the first and second conductors. The buffer amplifier has an input impedance that is impedance matched to an antenna impedance at and above but not below a frequency f.sub.c and is higher than the antenna impedance at frequencies substantially less than f.sub.c. The buffer amplifier also has an output impedance that is impedance matched to a system impedance at frequencies both above and below f.sub.c. A length of the first and second conductors is less than a wavelength at the frequency f.sub.c.

The detection and identification of unmanned aerial vehicles (UAVs) from a radio wave measurement result based on artificial intelligence (AI) are provided. A method of operating an apparatus to detect unmanned aerial vehicles (UAVs) includes generating a spectrogram, determining a first region to find a direction of the UAVs in the spectrogram, determining a direction of a first UAV of the UAVs based on signal values in the first region, determining a second region to identify a type of the first UAV in the spectrogram, and identifying the type of the first UAV based on signal values in the second region.

Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for positioning a radio signal receiver at a first location within a three dimensional space; positioning a transmitter at a second location within the three dimensional space; transmitting a transmission signal from the transmitter to the radio signal receiver; processing, using a machine-learning network, one or more parameters of the transmission signal received at the radio signal receiver; in response to the processing, obtaining, from the machine-learning network, a prediction corresponding to a direction of arrival of the transmission signal transmitted by the transmitter; computing an error term by comparing the prediction to a set of ground truths; and updating the machine-learning network based on the error term.

Using captured and stored wideband historical radio frequency data bearing information to the source of a signal of interest achieved using as few as two receivers and a plurality of commutating antennas. Wideband IQ data streams are received at two or more receivers and stored for later analysis. A first receiver is coupled to a reference antenna and a second receiver is commutatively coupled to a plurality of commutating antennas. Later, streams of wideband IQ data are retrieved for a select period of time and synchronized. From these streams a signal of interest identified and synchronously sampled over an acquisition interval by each receiver. Phase differences of the signal at each of the plurality commutating antennas is measured enabling a determination of the bearing to the common signal of interest.

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.

In examples, systems and methods for direction finding of electromagnetic signals are described. The device includes a first antenna configured to receive electromagnetic energy. The device also includes a second antenna configured to separately receive the same electromagnetic energy. The device further includes a radome located in a receiving pathway of the first antenna, where the radome is configured to cause a predetermined phase shift that varies based on an angular position of the receiving pathway. The device includes 1 or more radio receivers to receive the signals independently from the antennas. Additionally, the direction finding device includes a processor configured to determine an angle of arrival of the electromagnetic energy based on a comparison of a phase of the electromagnetic energy received by the first antenna to a phase of the electromagnetic energy received by the second antenna.

A laser measuring system comprising a laser transmitter and a laser receiver is provided. The laser transmitter includes one or more laser sources for projecting an initial laser pulse and a reflective surface. The laser receiver includes a first reflective surface for reflecting the initial laser pulse to provide a first reflected laser pulse, and a second reflective surface for reflecting the initial laser pulse to provide a second reflected laser pulse. The laser receiver further includes a photo detection unit for receiving 1) a first double reflected laser pulse produced by the first reflected laser pulse reflecting off the reflective surface of the laser transmitter, and 2) a second double reflected laser pulse produced by the second reflected laser pulse reflecting off the reflective surface of the laser transmitter. The laser receiver determines an orientation angle associated with the laser receiver based on the first and second double reflected laser pulse.

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.