A system includes a first transmission unit configure to emit a first terahertz wave, a second transmission unit disposed at a position different from a position of the first transmission unit and configured to emit a second terahertz wave, a detection unit for detecting at least one of a first reflected terahertz wave that is a part of the first terahertz wave reflected from an object, or a second reflected terahertz wave that is a part of the second terahertz wave reflected from the object, and outputting image data based on the detected terahertz wave, and a first control unit configured to, under a condition set based on the image data, control at least one of an operation of the first transmission unit or an operation of the second transmission unit.

One aspect of the invention provides a device for passive detection of the presence of a drone. The device includes: an antenna; a receiver in communication with the antenna to passively receive wireless signals; and a processor in communication with the receiver and programmed to determine whether a drone is present based on a pattern in the wireless signals emitted from the drone that is correlated with a physical movement of the drone. Another aspect of the invention provides a method for passively detecting the presence of a drone. The method includes: receiving a wireless signal at a device comprising an antenna, a receiver and a processor; and analyzing the wireless signal to determine whether the wireless signal includes a pattern in the signal that is indicative of a physical movement of a drone.

A microwave barrier system is provided, including: a first microwave barrier including a first microwave transmitter and receiver, the first transmitter including an electrically tunable microwave generator and being configured to be operated at a selectable microwave frequency; and a second microwave barrier including a second microwave transmitter and receiver, the second transmitter including an electrically tunable microwave generator and being configured to be operated at a selectable microwave frequency, the system being configured to determine microwave operating channels in an available frequency range for microwave barriers by one of the receivers, and to assign a respective microwave operating channel to at least one of the barriers to reduce mutual interference between the barriers, the barriers further including respective communication devices to signal-couple the respective receiver with the respective transmitter to transmit a microwave operating channel for operation of the barriers from the receivers to the transmitters.

A method and apparatus that identify a composition of an object using a non-contact chemical sensor provided. The method includes detecting an object based on information provided by a plurality of sensors, transmitting a chemical detection signal, from a non-contact chemical sensor, at the detected object, identifying a composition of the detected object based on an attenuation of the chemical detection signal, determining whether a path change is required based on the identified composition of the detected object, and controlling one or more actuators to stop a vehicle or adjust the path of the vehicle if the path change is required.

A system includes a transmission unit, a reception unit, and a lens unit and is placed in a passage, wherein in a case where a first plane that intersects a forward direction of the passage and is a surface of an object, and a second plane that intersects the forward direction of the passage, includes the lens unit, and is at a position different from a position of the first plane are set, a first area to which a terahertz wave from the transmission unit reflected from the first plane is emitted and the lens unit are disposed at positions different from each other on the second plane.

A system includes first and second gas cells, each comprising a respective sealed interior waveguide. The first gas cell contains a dipolar gas and the second gas cell does not contain a dipolar gas. The system includes first and second transmit antennas coupled to the first and second gas cells, respectively, to provide first and second electromagnetic waves to the interior of the first and second gas cells, respectively; first receive antenna coupled to the first gas cell to generate a first signal indicative of an amount of energy in the first electromagnetic wave after travel through the first gas cell; second receive antenna coupled to the second gas cell to generate a second signal indicative of an amount of energy in the second electromagnetic wave after travel through the second gas cell; processor configured to calculate a background-free signal based on a difference between the first and second signals.

An apparatus for producing an image of an object by electromagnetic radiation includes a transmitting device for producing the electromagnetic radiation, a plurality of transmitting antennas connected to the transmitting device for emitting the electromagnetic radiation, a plurality of receiving antennas, which receive the electromagnetic radiation emitted by the transmitting antennas, and a receiving device, connected to the plurality of receiving antennas, for receiving the electromagnetic radiation and a motor-driven rotating scanner. The transmitting antennas and the receiving antennas are arranged on the scanner. The scanner is set up in such a way that the transmitting antennas and the receiving antennas are rotatable at the same speed about an axis of rotation. The transmitting antennas and the receiving antennas are arranged in relation to one another in such a way that the object can be moved past them, and so in an operating mode of the apparatus the electromagnetic radiation is transported through the object or is reflected by the object.

The present disclosure relates to a monitoring method, a monitoring system and a control device for a human-body security-inspection device. The monitoring method includes: collecting operation parameters of preset monitoring points in target circuit modules of the human-body security-inspection device; obtaining parameter ranges according to module identifiers of the target circuit modules and monitoring-point identifiers of the preset monitoring points, wherein the parameter ranges are associated with the module identifiers and the monitoring-point identifiers respectively; determining whether the operation parameters are in the parameter ranges respectively, and then determining location information of a fault point according to the module identifiers and the monitoring-point identifiers if any of the operation parameters is not in a corresponding parameter range. Therefore, the present disclosure can quickly locate the position of the fault point, thus it is convenient in the maintenance and test work, and improve the efficiency of the maintenance and test work.

A vehicle-based method of determining the extent to which a target object is a single scatterer, said vehicle including a radar system including a radar transmit element, adapted to send a radar signal towards said target object, and an antenna receive array comprising a plurality M of a receive elements, providing a corresponding plurality of N radar receive channels, and adapted to receive radar signals reflected from said target object, said method comprising: a) transmitting a radar signal from said radar transmit element to said target object; b) receiving the reflected signal of the signal transmitted in step a) from the target object at said plurality of receiver elements; c) for each antenna element or channel, processing the received signal to provide amplitude or power data in the frequency domain; d) with respect to the data in step c), for each receive element/channel, determining the frequency with the maximum amplitude or power; e) determining the degree of variability of the results of step d) with respect to each receive element/channel; f) determining the extent to which the target object is a single scatterer based on the result of step e).

A system may comprise a scanner assembly and a radiometer. The radiometer may comprise a W-Band and F-Band receiver and an intermediate frequency processor. The system may be rotatably mounted to a bus via the scanner assembly.