According to one embodiment, a radar device includes a first and second radar units. The first radar unit includes a first substrate, and first transmit and receive array antennas. The second radar unit includes a second substrate, and second transmit and receive array antennas. A shape of the first substrate corresponds to a shape of the second substrate. A relative position of the first transmit or receive array antenna in the first substrate corresponds to a relative position of the second transmit or receive array antenna in the second substrate.

Described herein are systems for detecting a representation of an object in a radio frequency (RF) image. The system transmits one or more first RF signals toward an object, and receives one or more second RF signals, associated with the one or more transmitted RF signals, that have been reflected from the object. The system determines a plurality of first feature maps corresponding to a RF image associated with the one or more second RF signals. The system combines the plurality of first feature maps. The system further detects a representation of the object in the RF image based at least in part on the combined plurality of first feature maps.

The present invention relates to a method for detecting (S) a target object using a detector (I) employing radiant energy, comprising the following steps: SI: placing an individual to be inspected in a first position within the detector (I); S2: acquiring first signals representative of a radiant energy when the individual to be inspected is in the first position; S3: placing the individual to be inspected in a second position within the detector (I), the second position being different from the first position; and S4: acquiring second signals representative of a radiant energy when the individual to be inspected is in the second position: and S5: on the basis of the first signals and of the second signals, producing an electronic image so as to determine whether the individual to be inspected is carrying, wearing or bearing a target object.

Described herein are examples of evaluating electromagnetic energy reflection data of security scans. In embodiments, a method to evaluate electromagnetic energy reflection data determines whether electronic information of a security scan contains an anomaly, and identifies an anomaly location in the electronic information corresponding to the anomaly. The method determines a subset of the electronic information corresponding to the anomaly location, determines anomaly attributes using the subset of the electronic information, and evaluates the anomaly attributes using a database of reference items by comparing anomaly attributes to respective reference characteristics of reference items or identity information. When a comparison meets the respective match criterion for the given reference item, the method assigns to the anomaly the respective identifier as an anomaly identifier.

A single frequency, or very narrow frequency band, microwave imaging system is described herein. A microwave imaging system can include an array transmitter; an array receiver; and a computing device that receives signals detected from the array receiver, transforms the signals received by the array receiver into independent spatial measurements, constructs an image using the independent spatial measurements, and outputs a reconstructed image. The array transmitter and the array receiver may each have a plurality of independently controllable metasurface resonant elements.

A permittivity sensor, for determining an image of a distribution of permittivity of a material of an object in a scene, comprising an input interface, a hardware processor, and an output interface is provided. The input interface is configured to accept phaseless measurements of propagation of a known incident field through the scene and scattered by the material of the object in the scene. The hardware processor is configured to solve a multi-variable minimization problem over unknown phases of the phaseless measurements and unknown image of the permittivity of the material of the object by minimizing a difference of a nonlinear function of the known incident field and the unknown image with a product of known magnitudes of the phaseless measurements and the unknown phases. Further, the output interface is configured to render the permittivity of the material of the object provided by the solution of the multi-variable minimization problem.

In one aspect, a system for obtaining dielectric properties of an object is disclosed, which comprises a plurality of transceivers for generating radiation in the microwave or millimeter-wave region of the electromagnetic spectrum. The transceivers are positioned in spatially fixed relationships relative to one another. The system further includes a controller for selectively activating the transceivers for irradiating at least a portion of the object and detecting at least a portion of the radiation reflected from said portion of the object in response to the irradiation, where each of the activated transceivers generates a signal in response to detection of the reflected radiation. The reflected signals are analyzed to determine a plurality of reflectivity coefficients corresponding to different discrete locations of the object, and the reflectivity coefficients are used to determine the complex permittivity of the discrete locations.

A radar-based security screening system for detecting objects is described. The screening system includes a radar transmitter, a radar receiver, and a processing unit. In use, the radar transmitter steers a radar beam across a screening volume. The radar receiver, in turn, receives a return signal from an object over time as the object moves in the screening volume to create a three-dimensional temporal signature for the object. The processing unit classifies the three-dimensional temporal signature utilizing a classification process based on a deep neural network model, and provides an alert when the object is classified as an object of interest. During screening, a screened person is not required to remain still in a confined volume and is not exposed to harmful radiation.

This invention is related to a supervision system that monitors automated movements performed by components of an medical imaging modality, in order to ensure that the moving components behave as expected, while identifying at the same time potential conflicts with (alien) objects or persons in the medical scene. The invention is based on the analysis of differences between measured distance data obtained by a detector that is mounted on the medical imaging modality, and a calculated virtual model of the geometric state of the modality components in the medical scene.

An electromagnetic non-line-of-sight imaging method based on time reversal and compressed sensing is provided. The electromagnetic signal passively scattered by the target behind the obstacle is received by the antenna, the contour imaging of the target is realized by using compressed sensing, the signal-to-noise ratio of the electromagnetic signal of the target is improved by using time reversal for the contour area, so as to achieve the purpose of staring at and detecting the non-line-of-sight target; a random radiation signal is transmitted for multiple times through active metasurface modulation, compressed sensing is performed for calculation imaging after receiving the signal to judge the number of targets and the contour area in the occluded area; for the target contour area, the amplitude and phase of signals obtained at different positions are adjusted by the active metasurface, so as to focus and scan the electromagnetic signals at different positions behind the obstacle. The method can detect the target in the unsealed scene behind the wall and the metal structure (3) which cannot be penetrated by electromagnetic signals, and expand the detection capability of the traditional detection and imaging radar.