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 GPU-based human body microwave echo simulation method includes: transmitting emulation input parameters from the memory of a CPU host into the display memory of a GPU device; configuring, at the CPU host, parallel computing network parameters to be run at the GPU device; initiating a kernel function for human body microwave echo simulation preset in the CPU host; computing the kernel function in parallel, in a plurality of processing kernels of the GPU device, in a multi-threaded manner, according to the parallel computing network parameters, to obtain simulation echoes of human body microwaves; transmitting the obtained simulation echoes of human body microwaves from the GPU device back to the CPU host. The method makes full use of the characteristic that a GPU can perform parallel computing to accelerate the echo simulation process, greatly improving the real-time performance of echo simulation of a human body microwave scanning and imaging system.

Abstract: A three-dimensional imaging system and method based on rotational scanning is disclosed. The system includes a column-shaped frame with a column-shaped side; a transceiving antenna array element arranged on the column-shaped side that transmits a micro-wave detection signal to a detected object located in the column-shaped frame and receives an echo signal reflected back from the detected object; a signal transceiving device that generates the micro-wave detection signal and sends same to the transceiving antenna array element and processes the echo signal; a rotation control device that controls rotational movement of the transceiving antenna array element so that the transceiving antenna array element transmits the micro-wave detection signal to the detected object in a plurality of angles; and a positioning trigger fixedly arranged on the column-shaped frame and configured to trigger the signal transceiving device when the transceiving antenna array element arrives at a position of the positioning trigger.

Abstract: A security check method includes: pre-creating at least four concurrently operating threads, one thread being responsible for movement control and data acquisition, one thread being responsible for imaging processing, one thread being responsible for interface displaying, and one thread being responsible for target detection and recognition; then the four concurrently operating threads divide original echo data of a human body to be checked into data of a plurality of adjacent overlapped azimuthal segments during data processing and perform individual processing on the data of each azimuthal segment. The security check system includes a thread creating unit, a first thread parallel unit, a second thread parallel unit, a third thread parallel unit, a fourth thread parallel unit, and a thread loop control unit. Because subsequent data processing is not required to be performed after the acquisition of all data is completed, the time for a security check process is reduced.

Abstract: A millimeter wave security inspection instrument debugging system and a millimeter wave security inspection instrument debugging method, which are used for debugging the imaging definition of a millimeter wave holographic imaging security inspection system. A main control apparatus is used for generating a millimeter wave detection signal and a reference signal. The main control apparatus is also used for, where a millimeter wave transmitting antenna, a millimeter wave receiving antenna and a detected object are respectively located at different relative positions, transmitting the millimeter wave detection signal to the detected object by means of the millimeter wave transmitting antenna, and receiving an echo signal reflected from the detected object by means of the millimeter wave receiving antenna, and then using a holographic image technique to perform three-dimensional imaging according to the reference signal and the echo signal.

Abstract: This invention provides millimeter wave holographic 3D imaging detection system, which comprises: a transmitting antenna configured to transmit a millimeter wave transmitting signal to an object to be detected; a receiving antenna configured to receive an echo signal from the object to be detected; a millimeter wave transceiving module configured to generate the millimeter wave transmitting signal transmitted to the object to be detected and receive and process the echo signal from the receiving antenna; a scanning device configured to support the millimeter wave transceiving module, the transmitting antenna and the receiving antenna, and move the millimeter transceiving module, the transmitting antenna and the receiving antenna along a preset track, so as to scan the object to be detected with millimeter waves; a data gathering and processing module configured to gather and process the echo signal output from the millimeter wave transceiving module to generate a 3D image of the object to be detected; and an

Abstract: The invention relates to a power adjustment method and apparatus, and a human body security check device. An adjustable power attenuator is provided in a millimeter wave signal transmitting link of the millimeter wave transceiver. The method comprises: obtaining a current humidity value by detecting the ambient humidity around the millimeter wave transceiver using a preset humidity sensor; determining a target power attenuation value of the adjustable power attenuator according to the current humidity value, the sum of the target power attenuation value and a power attenuation value caused to a millimeter wave signal by the ambient humidity being a constant value; and controlling the adjustable power attenuator to adjust its power attenuation value to be consistent with the target power attenuation value. The solution can reduce radiation hazard while ensuring the definition of an image.

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: A close range microwave imaging method and system is provided. The method comprises: controlling a linear antenna array consisting of a preset number of antennas to rotate along a preset arc trajectory so as to scan a target region; controlling the linear antenna array to acquire a preset number of echo data at azimuthal positions on the arc trajectory and to send an echo data set constituted by the preset number of echo data to a signal processing device until the linear antenna array completes the acquisition of echo data at preset azimuthal positions on the arc trajectory; and controlling, every time the signal processing device receives the echo data set, the signal processing device to perform imaging processing on the echo data set.

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: A millimeter-wave three-dimensional holographic imaging method and system. The method comprises: transmitting a continuous frequency wave to a measured human body, and receiving an echo signal reflected back; performing Fourier transform, phase compensation, inverse Fourier transform, and “non-uniform sampling to uniform sampling” interpolation; and projecting three-dimensional echo data to obtain two-dimensional reconstruction data, and generating a two-dimensional reconstructed image.

Abstract: An electrically scanned array antenna device applied to a millimeter wave imaging system is provided. The electrically scanned array antenna device comprises an adjustable light source for outputting an optical signal with an adjustable wavelength; an electro-optical modulation module; an optocouple; a time delay module for performing optical delay of different duration on each modulated signal, and correspondingly changing the duration of the optical delay according to the wavelength of the optical signal to obtain modulated signals of different phases; an optical detector; and an array antenna. The millimeter wave is loaded on the optical signal with an adjustable wavelength to obtain a modulated signal; the modulated signal is divided into multiple signals; time delay of different duration is performed on each signal; and millimeter wave signals of different phases are obtained after demodulation and are simultaneously transmitted to scan an object to be measured.

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 millimeter wave image based human body foreign object detection method, comprising: acquiring a millimeter wave gray scale image of a human body; according to a pre-determined foreign object imaging characteristic, extracting from the millimeter wave gray scale image a foreign object area image; according to a pre-determined foreign object image recognition algorithm, performing calculations on the foreign object area image, and acquiring a foreign object image from the foreign object area image; displaying the foreign object image as a foreign object detection result. Also provided is a millimeter wave image based human body foreign object detection system.

Abstract: This invention provides a security check apparatus for multiple human bodies based on linear frequency modulation, which comprises a scanning device, a millimeter wave signal transceiver module, and an image processing unit. The scanning device comprises several detection seats and several guideways and motors arranged on the detection seats; the detection seats are configured to accommodate persons to be security checked; a set of the millimeter wave signal transceiver modules are arranged on each guideway, and each millimeter wave signal transceiver module is driven by the motor to move along the guideway; the several detection seats are arranged in longitudinal direction. The millimeter wave signal transceiver modules are configured to transmit millimeter wave signals to the persons to be security checked and receive millimeter wave signals reflected from the persons to be security checked.

Abstract: A disclosed method includes: dividing an signal into a first signal and a second signal; performing frequency multiplication and amplification on the first signal to obtain an intermediate signal of corresponding power and frequency, and using the second signal as a local oscillation signal. The method further includes dividing the intermediate signal into a first intermediate signal and a second intermediate signal, and using the first intermediate signal as a reference signal; performing frequency mixing on the second intermediate signal and the local oscillation signal to obtain a mixed signal, which is a high-frequency millimeter wave signal; transmitting the mixed signal by a transmitting antenna; and performing frequency mixing on the signal received by a receiving antenna and the reference signal to obtain an intermediate-frequency controllable signal having a frequency consistent with that of the output signal of the signal source.

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: A servo rotary scanning system of three-dimensional holographic imaging may include a servomotor (20) having a first angle sensor (21), a second angle sensor (30), a control component (40), a servo driver (50) and a rotary frame (10), the servo rotary scanning system of three-dimensional holographic imaging is a full-closed loop servo control system, the second angle sensor (30) detects an actual rotating angle of the rotary frame (10) and feeds back a frame feedback signal to the control component (40), an instruction signal in the control component (40) is compared with the frame feedback signal to generate a following error, the first angle sensor (21) detects an output rotating angle of the servomotor (20) and feeds back a motor feedback signal to the servo driver (50), and the servo driver (50) controls the servomotor (20) to rotate according to the following error and the motor feedback signal.

Abstract: A terahertz security check method and system may include: a terahertz scanning device collecting a terahertz original image of a human body under test, and sending the same to a central server that identifies the terahertz original image, and determines whether the human body under test carries an article. If so, the image is marked with the position of the article and sent to a monitoring terminal. The monitoring terminal correspondingly marking the position of the article on a pre-stored human body cartoon image, and displaying the terahertz original images before and after marking to monitoring personnel, so that the monitoring personnel determine whether the central server has an identification error; and if so, the monitoring terminal changing a marker on the human body cartoon image, and sending the changed cartoon image to a client of security check personnel for displaying.