An aircraft flight control apparatus includes a flight track acquiring unit and a determining unit. The flight track acquiring unit is configured to measure a position of an aircraft to acquire a flight track of the aircraft. The determining unit is configured to determine, when an own-aircraft deviation amount gradually increases, whether the aircraft receives a spoofed signal as a satellite positioning system signal, on the basis of the own-aircraft deviation amount. The own-aircraft deviation amount is an amount of deviation of the flight track acquired by the flight track acquiring unit from a scheduled flight route of the aircraft.

A base station of a communication system may include an antenna; a memory; and a processor. The processor analyzes a signal received through the antenna to determine if the received signal is a signal transmitted from a fake base station. Based on a determination that the source of the received signal is the fake base station, the processor generates a random access preamble signal for accessing the fake base station. The processor transmits the generated random access preamble signal through the antenna. Thus, the base station may effectively defend against an attack from a fake base station by detecting the fake base station based on collected information of a neighboring base station and causing radio resources of the detected fake base station to be exhausted. Various other embodiments are possible.

System and for signal re-transmission including a channelizer, a signal-effect-processor and a controller. The signal-ef-fect-processor includes a plurality of sub-band-processors and a summer. The channelizer receives a sampled Intermediate-Frequency signal exhibiting a first sampling-rate. The channelizer produces a plurality of sub-band-signals, each associated with a respective sub-band of the Intermediate-Frequency signal. Each sub-band-signal exhibit a second sampling-rate lower than the first sampling-rate. Each of at least one selected sub-band-processor receives a respective sub-band-signal, introduces at least one effect to the respective sub-band-signal, and increases the sampling-rate of the respective sub-band-signal to the first sampling-rate, thereby producing a respective affected sub-band re-transmit signal. Each selected sub-band-processor is further provides the respective affected sub-band re-transmit signal to a respective input of the summer. The summer sums the inputs thereof to produce a wideband affected re-transmit signal. The controller selects the selected sub-band processor and controls settings of the at least one effect.

A communications system and methods for covert communications are provided. A first transmitter that transmits an information carrying signal to a target receiver, a second transmitter and a third transmitter transmit jamming signals to the target receiver, such that the information carrying signals and the jamming signals are interleaved when received by the target receiver The information carrying signals and the jamming signals can be at least partially overlapping by an eavesdropper.

In some examples, a system includes a transceiver configured to receive surveillance messages from Y target vehicles, where Y is an integer greater than two. The system includes processing circuitry configured to determine predicted positions of the Y target vehicles based on the surveillance messages. The processing circuitry is also configured to determine reported positions of the Y target vehicles based on later received surveillance messages. The processing circuitry is further configured to determine that respective differences between the respective predicted position and the respective reported position for X of the Y target vehicles is greater than a threshold distance. The processing circuitry is configured to determine that Global Navigation Satellite System interference has occurred in response to determining that X divided by Y is greater than a threshold level.

Disclosed is a method of producing an output signal from a signal generator, comprising: determining a driving input to the signal generator, the driving input for driving the signal generator to provide a predetermined output signal, wherein the output signal includes at least one frame, the at least one frame comprising an active period and a dummy period and wherein the active period and dummy period are determined by the driving input. Also disclosed is a method of producing an output signal from a signal generator, comprising: receiving a synchronisation signal; obtaining an input signal for controlling the signal generator to generate an output signal comprising at least one frame wherein the at least one frame comprises at least one active period and at least one dummy period; producing the output signal comprising a series of frames; and, synchronising the output signal with the synchronisation signal by varying a duration of the at least one of the dummy period or active period.

A interference detection device (22) perform the following actions: receiving individual position data from mobile terminals (4(j)) which individual position data indicates an area (12(j)) in which individual ones of the mobile terminals (4(j)) are located based on positioning signals received by the mobile terminals (4(j)); identifying if individual position data may have been affected by one or more interfering signals transmitted by interfering device (14(m)) and interfering with the positioning signals; (A) identifying if a number of mobile terminals (4.sub.v(j)) in a first area (18) is higher than a maximum threshold number, and, if so, determining that individual position data of the number of mobile terminals (4.sub.v(j)) may have been affected by the interfering signals; or (B) identifying if a number of the mobile terminals (4(j)) in a second area (36) is lower than a minimum threshold number; and, if so, determining that individual position data of the number of mobile terminals (4(j)) may have been affected by interfering signals; or (C) receiving further individual position data which indicates further areas (18) in which mobile terminals (4(j)) are located based on another positioning technique than a positioning technique used to determine the individual position data as received from the mobile terminals (4(j)); determining if the areas (12(j)) overlap with the further areas (18) at least to a minimum extent, and, if not, determining that individual position data of the mobile terminals (4(j)) may have been affected by the interfering signals.

A system, method and computer program product for controlled drone descent, and deactivation, including a drone deactivation system; and a location system. The drone deactivation system calculates positioning, signal reception, signal strength, and signal identification parameters of a target drone from the location system, and determines an attack method based on the calculated parameters. The drone deactivation system employs the determined attack method against the target drone for forcing at least one of controlled drone descent, and deactivation of the target drone.

Some embodiments of the time resilient system and methods disclosed herein can be configured to detect and defend against invalid time signals. According to various embodiments of the disclosed technology, the time resilient system include a receiver for collecting time signals sourced from an external clock. By way of example only, the external clock may be a high precision clock housed within a Global Positioning System. Other embodiments may include an internal clock calibrated to a time reflected on the external clock so that the internal clock and the external clock are synchronized. Additionally, a controller may monitor changes in time signals of the external over a period of time against the internal clock, where the system is alerted of a timing attack when the time signals collected from the receiver deviate a pre-determined time range with the time of the internal clock.

Systems, methods, and apparatus for identifying, tracking, and disrupting UAVs are described herein. Sensor data can be received from one or more portable countermeasure devices or sensors. The sensor data can relate to an object detected proximate to a particular airspace. The system can analyze the sensor data relating to the object to determine a location of the object and determine that the object is flying within the particular airspace based at least in part on location data. A portable countermeasure device can be identified that corresponds to the location of the object. The system can transmit information about the object to the identified portable countermeasure device. The portable countermeasure device can transmit additional data relating to the object to the system.