A radio presence-advertising signal (PAS) a PAS emitter is simultaneously received at two or more co-located directional antennas that are coupled to respective radio receivers. The antennas have reception sensitivity lobes that overlap to define a region of interest at the overlap. Substantially cotemporaneous signal strength indications are obtained from the radio receivers. A difference signal representative of a difference between two of the obtained signal strength indications of the respective antennas is generated. An average signal representative of a running average of two or more of the obtained signal strength indications is generated and used to produce a normalized confidence indicator indicating a level of confidence that the PAS emitter is disposed inside (e.g., centered in) the region of interest or alternatively indicating a level of confidence that the PAS emitter is disposed outside the region of interest. Action is taken or avoided based on the confidence 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.

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.

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.

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.

An object orientation system, an object orientation method and an electronic apparatus are provided. A signal transmitter includes a directional antenna and emits a first wireless signal. A plurality of signal receivers are respectively disposed in a plurality of orientations. The signal receivers receive the first wireless signal and measure a plurality of first received signal strength indicators of the first wireless signal. The electronic apparatus is coupled to the signal receivers, estimates a plurality of strength variation data of the first received signal strength indicators measured by the signal receivers, and obtains orientation information of the signal transmitter according to the strength variation data corresponding to the signal receivers.

An object orientation system, an object orientation method and an electronic apparatus are provided. A signal transmitter includes a directional antenna and emits a first wireless signal. A plurality of signal receivers are respectively disposed in a plurality of orientations. The signal receivers receive the first wireless signal and measure a plurality of first received signal strength indicators of the first wireless signal. The electronic apparatus is coupled to the signal receivers, estimates a plurality of strength variation data of the first received signal strength indicators measured by the signal receivers, and obtains orientation information of the signal transmitter according to the strength variation data corresponding to the signal receivers.

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.

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.

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.