Abstract: A close-range microwave imaging method includes: implementing Fourier transform in a pre-set rotation axis direction on an echo signal reflected from a target object and acquired by rotating an array antenna around the pre-set rotation axis to obtain a first echo signal, wherein the first echo signal is represented in polar coordinates; multiplying the first echo signal by a pre-set reference function to obtain a second echo signal; converting the second echo signal into rectangular coordinates by a pre-set algorithm to obtain a third echo signal; and implementing three-dimensional Fourier transform on the third echo signal to obtain three-dimensional image data of the target object. By means of the method, three-dimensional image data of a target object can be obtained fast, fast imaging of the target object can be realized, the data processing amount is small, the imaging precision is high and the method is easy to implement.

Abstract: A millimeter-wave real-time imaging based safety inspection system and safety inspection method. The safety inspection system includes a conveying device (10), a millimeter wave transceiver module (11), an antenna array (17, 18), a switch array (16a, 16b), a switch control unit (15a, 15b), a quadrature demodulation and data acquisition module (12), and an image display unit (13). By using an Inverse Synthetic Aperture Radar (ISAR) imaging principle, the millimeter-wave real-time imaging based safety inspection system performs real-time imaging on an object to be inspected when the object moves, so that not only the imaging speed is improved, but also the field of view is enlarged. A safety inspector can determine whether an inspected person carries dangerous goods by observing a three-dimensional diagram of the inspected person, thereby eliminating the inconvenience caused by back-and-forth movement of a safety inspection device used by the safety inspector around the inspected person.

Abstract: A human body gender automatic recognition method includes: acquiring a current millimeter wave grayscale image, and determining gender part region positions of a human body in the millimeter wave grayscale image according to a pre-set body proportion; extracting a region sub-image corresponding to the gender part region position; performing dimension normalization on the region sub-image to obtain a normalized region sub-image; performing feature information extraction on the normalized region sub-image to obtain feature information about the normalized region sub-image; recognizing the millimeter wave grayscale image by means of each pre-set classifier, and respectively outputting results; and integrating the output results to obtain a classification recognition result of the millimeter wave grayscale image. The method has relatively high recognition rate and calculation efficiency and solves the problem of a privacy protection and detection method in a millimeter wave security inspection system.

Abstract: An amplitude-phase correction method and system for a microwave imaging system are provided. The method comprises: carrying out data processing, in a range direction, on an echo signal reflected from a target object and acquired by a linear array antenna according to a first pre-set algorithm to obtain a compressed signal in the range direction; extracting a range value corresponding to the maximum amplitude, in the range direction, of the compressed signal in the range direction; carrying out time delay compensation on the echo signal according to the range value to obtain a time-delay-compensated signal; carrying out data processing on the time-delay-compensated signal according to a second pre-set algorithm to obtain an amplitude-phase signal; and carrying out amplitude-phase correction on the echo signal according to the time-delay-compensated signal and the amplitude-phase signal to obtain a corrected echo signal.

Abstract: Provided are a direct wave suppression method and system for a microwave imaging system. The method includes a series of filtering operations, such as conversion from a frequency domain to a time domain, filtering, conversion from the time domain to the frequency domain, and cancellation subtraction, on an echo signal set composed of echo signals obtained by a vertical linear array antenna at all the equivalent antenna collection positions thereof.

Abstract: A disclosed system includes a support frame including a plurality of surfaces, a millimeter-wave transmission link that generates a millimeter-wave transmission signal, a plurality of millimeter-wave array antennas, a millimeter-wave reception link, and an image processing device. The millimeter-wave array antennas are disposed on different surfaces of the support frame, and transmit millimeter-wave transmission signals from different angles to a to-be-detected object and receive echo signals reflected from the to-be-detected object. By providing the millimeter-wave array antennas on each of the plurality of surfaces of the support frame, and transmitting millimeter-wave transmission signals from different angles to a to-be-detected object and receiving echo signals reflected from different angles of the to-be-detected object, a three-dimensional image of the to-be-detected object can be established, thereby achieving omni-directional detection of the to-be-detected object.

Abstract: This invention relates to a method and a device for human body gender detection in a microwave image. The structure feature of a human body itself as well as the constructed vertical direction spatial distribution histogram and horizontal direction spatial distribution histogram are used to accurately locate the chest position and the crotch position of the human body. A human body chest subimage is extracted according to the chest position, and a human body crotch subimage is extracted according to the crotch position. Then, the feature values of the human body chest subimage and the human body crotch subimage are respectively extracted by a feature value extraction algorithm, and the human body gender is automatically identified according to the feature values. The technical solution of this invention is simple, and after experimental verification, can be effectively applied in actual microwave security check system.

Abstract: The present invention discloses a mail detection device and method. The device comprises a broad-band terahertz generator, a collimator, a beam splitter, a fixed reflector, a movable reflector, a wave buncher, a matrix detector, an acquisition card and an information processing module; wherein the information processing module is used for generating a terahertz image of a mail to be detected according to the electric signals sent by the acquisition card when the movable reflector is motionless; and when finding suspicious articles according to the terahertz image of a mail to be detected, the information processing module controls the movable reflector to move, and generates spectral information of the suspicious articles according to an electric signal sequence sent by the acquisition card during the movement of the movable reflector.

Abstract: The present invention discloses a mail detection device and method. The device comprises a broad-band terahertz generator, a collimator, a beam splitter, a fixed reflector, a movable reflector, a wave buncher, a matrix detector, an acquisition card and an information processing module; wherein the information processing module is used for generating a terahertz image of a mail to be detected according to the electric signals sent by the acquisition card when the movable reflector is motionless; and when finding suspicious articles according to the terahertz image of a mail to be detected, the information processing module controls the movable reflector to move, and generates spectral information of the suspicious articles according to an electric signal sequence sent by the acquisition card during the movement of the movable reflector.