Two antennas receive three kinds of radio waves with different frequencies. A computation unit determines the arrival direction of the three kinds of radio waves arriving at the two antennas after propagating along two mutually different paths from a single transmit point in accordance with receive signals of the three kinds of radio waves with different frequencies received individually by the two antennas.

A direction detection device includes: antennas that receive a 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 in 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 an intensity difference between the two antennas and a phase difference between the two antennas, of the received wave; an extractor that extracts, from the table, a received-wave arrival direction corresponding to the detected intensity difference, for each combination; a calculation unit that calculates a received-wave arrival direction corresponding to the detected phase difference; and a comparator that compares the extracted received-wave arrival direction with the calculated received-wave arrival direction to acquire a matched received-wave arrival direction.

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 apparatus for estimating an angle of arrival, comprises: a window setting unit for setting a window time that is a time interval for comparing a template signal and each of a plurality of reception signals obtained by receiving a transmission signal transmitted a pre-designated number of times ; a template generator that generates a template signal of a waveform corresponding to the transmission signal, by adjusting a generation time point in units of the window time; a plurality of signal correlators provided corresponding to each of the plurality of antennas, and detecting a level of a correlation signal obtained by correlating a corresponding reception signal; and an angle of arrival determination unit, determining a reception time at which each of the plurality of reception signals is received by a corresponding antenna, and estimating the angle of arrival of the transmission signal using a difference between the determined reception times.

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 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.

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.

Disclosed are examples of systems, apparatus, methods and computer program products for locating unmanned aerial vehicles (UAVs). A region of airspace may be scanned with two scanning apparatuses. Each scanning apparatus may include one or more directional Radio Frequency (RF) antennae. The two scanning apparatuses may have different locations. Radio frequency signals emitted by a UAV can be received at each of the two scanning apparatuses. The received radio frequency signals can be processed to determine a first location of the UAV.