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.

A receiver system comprising: an input terminal configured to receive input signalling comprising a plurality of antenna-signals, wherein the plurality of antenna-signals each comprise information that corresponds to a first-frequency-bin and a second-frequency-bin. AoA-blocks can determine a first-angle-of-arrival and a second-angle-of-arrival associated with the first- and second-frequency-bins. A first-weighting-determination-block configured to, based on the first-angle-of-arrival and the second-angle-of-arrival, either: set first-weighting-values as values for constructively combining the information that corresponds to the first-frequency-bins of the plurality of antenna-signals; or set first-weighting-values as values for destructively combining the information that corresponds to the first-frequency-bins of the plurality of antenna-signals.

A receiver system comprising: an input terminal configured to receive input signalling comprising a plurality of antenna-signals, wherein the plurality of antenna-signals each comprise information that corresponds to a first-frequency-bin and a second-frequency-bin. AoA-blocks can determine a first-angle-of-arrival and a second-angle-of-arrival associated with the first- and second-frequency-bins. A first-weighting-determination-block configured to, based on the first-angle-of-arrival and the second-angle-of-arrival, either: set first-weighting-values as values for constructively combining the information that corresponds to the first-frequency-bins of the plurality of antenna-signals; or set first-weighting-values as values for destructively combining the information that corresponds to the first-frequency-bins of the plurality of antenna-signals.

A method for direction finding of at least one incoming signal with a direction finding antenna unit is described, the direction finding antenna unit comprising at least an antenna system having several antenna elements. One antenna element is used as a reference antenna element. A subset of the several antenna elements is selected when the reference antenna element detects the incoming signal, the selected subset ensuring the best signal-to-noise ratio of all possible subsets of the several antenna elements with respect to the reference antenna element. Phase difference and orientation of the incoming signal are related to the reference antenna element. Further, a direction finding antenna unit is described.

A method of determining incident angles of Radio Frequency, RF, signals received by an antenna array comprising a plurality of antennae is described. The method comprises generating a plurality of direction finding, DF, signals based on antenna signals received from the antenna array, wherein each DF signal corresponds to a respective antenna array element and each antenna array element corresponds to one or more antennae. A plurality of DF spectra are then generated, each DF spectrum corresponding to a respective DF signal and comprising measured values of signal power at two or more given respective frequencies. An incident signal angle is calculated for each given frequency, based on the measured values of power at the frequency, the configuration of the antennae in the antenna array and antenna gain patterns corresponding to the antenna array elements.

A method of determining incident angles of Radio Frequency, RF, signals received by an antenna array comprising a plurality of antennae is described. The method comprises generating a plurality of direction finding, DF, signals based on antenna signals received from the antenna array, wherein each DF signal corresponds to a respective antenna array element and each antenna array element corresponds to one or more antennae. A plurality of DF spectra are then generated, each DF spectrum corresponding to a respective DF signal and comprising measured values of signal power at two or more given respective frequencies. An incident signal angle is calculated for each given frequency, based on the measured values of power at the frequency, the configuration of the antennae in the antenna array and antenna gain patterns corresponding to the antenna array elements.

Provided herein is a compact and economical direction finding antenna using a mono-pulse antenna system, where a plurality of antenna elements are disposed in a circular array. The directional antennas may be formed by any type of antenna element, including a patch or reflector. The antenna beams of the directional antenna elements overlap, so that from any azimuthal direction, the point is covered by more than one antenna beam. Signals from each pair of adjacent antenna elements of the circular array are processed in order to determine the angle of arrival of a received signal.

Provided herein is a compact and economical direction finding antenna using a mono-pulse antenna system, where a plurality of antenna elements are disposed in a circular array. The directional antennas may be formed by any type of antenna element, including a patch or reflector. The antenna beams of the directional antenna elements overlap, so that from any azimuthal direction, the point is covered by more than one antenna beam. Signals from each pair of adjacent antenna elements of the circular array are processed in order to determine the angle of arrival of a received signal.

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.

In a method for determining a 3D directional vector between a sending device and a receiving device, the receiving device comprises at least two antenna arrays that each comprise a plurality of linearly arranged antenna elements that are aligned to different orientations. The method comprises receiving, with the antenna arrays, a signal sent from the sending device, sampling, based on the received signal, outputs of each antenna element of each antenna array at a plurality of time instants, determining, for each antenna array, a Propagator Direct Data Acquisition, PDDA, pseudo-spectrum by performing a 1-dimensional PDDA, 1D-PDDA, based on the sampled outputs of the respective antenna array and on a plurality of steering vectors associated with the respective antenna array, determining a maximum of each PDDA pseudo-spectrum, determining an angular quantity () for each antenna array based on the respective maximum of the PDDA pseudo-spectrum, and determining the 3D directional vector based on the angular quantities () of each antenna array and on the orientations of the antenna arrays.