Tsinghua University

Beijing Institute of Satellite Environmental Engineering

Xiao-Ping Zheng

Hua Geng

Xiao-Jiao Deng

Bin Wang

Zhen-Yuan Sun

Bin Cao

Xia-Hui Han

Sheng-Chuang Bai

De-Jian Zhang

Li Ping Yang

Jia Qi Li

Shan Zhang

Zhi-Jie Li

Jia-Ming Liu

Zhan Ou

Guo-Min Zuo

A method for discovering an unexploded ordnance in a target area includes: acquiring first feedback signals respectively corresponding to detection regions, the first feedback signals being first induced electromotive force signals; judging whether there is any abnormal signal in the first feedback signals, if there is the abnormal signal, determining the detection region corresponding to the abnormal signal is an abnormal region; acquiring second feedback signals respectively corresponding to detection sites in the abnormal region, the second feedback signals being magnetic field gradient signals; acquiring third feedback signals respectively corresponding to the detection sites, the third feedback signals being second induced electromotive force signals; acquiring location information of the detection sites; obtaining a feature spatial distribution map of the abnormal region; and judging whether there is any unexploded ordnance in the abnormal region according to the feature spatial distribution map.

Method for discovering unexploded ordnance by detecting transient electromagnetic field in combination with magnetic field gradient

A magnetism detection apparatus includes a detection device, at least one first locating device, and a central control device. The detection device includes an array of detection assemblies arranged in a same plane. The array of detection assemblies is configured to detect magnetic fields and output magnetic field signals corresponding to locations of the detection assemblies. The at least one first locating device is disposed on one of the detection assemblies to locate this detection assembly and output a first coordinate signal corresponding to this detection assembly. The central control device is communicatively and respectively connected to each of the detection assemblies and the at least one first locating device, and configured to process the magnetic field signals and the first coordinate signal.

Magnetism detection apparatus for underwater unexploded ordnance and method for controlling the same

A detection method for discovering an unexploded ordnance includes: surrounding a detection region with a transmitting coil and surrounding a detection site with a second receiving coil; conducting the transmitting coil with a second electric current; respectively acquiring a plurality of second feedback signals at a plurality of second feedback time points; partitioning the transmitting coil into a plurality of dipoles, and acquiring a plurality of distance values r respectively between the plurality of dipoles and the detection site; respectively calculating feedback depths according to feedback time periods; respectively calculating apparent resistivity values corresponding to the feedback depths; obtaining an apparent resistivity distribution in depth at the detection site according to the apparent resistivity values and the feedback depths; and judging whether there is any unexploded ordnance at the detection site according to the apparent resistivity distribution in depth.

Transient electromagnetic field detection apparatus having dynamic emission source in combination with static emission source and transient electromagnetic field detection method for discovering unexploded ordnance

The present application provides a terahertz leaky-wave antenna measuring system in which an original feed enclosed by a structure is replaced with a probe. The probe is moved along grooves in different directions to acquire amplitude and phase information in real-time to achieve an antenna equivalent measurement according to the reciprocity theorem, wherein the feed and the structure are separated from each other.

Terahertz leaky-wave antenna measuring system

A method for collecting and processing terahertz spectral imaging data includes: scanning an object to generate terahertz spectral data having a hyper- or low-spectral resolution respectively at a plurality of pixel points; collecting the terahertz spectral data and recording coordinate data of each pixel point, thereby obtaining a mixed data including a hyper-spectral data and a low-spectral data corresponding to different pixel points; constructing a hyper-spatial and low-spectral imaging data-cube from the mixed data; extracting a hyper-spectral data-set from the mixed data; and reconstructing a hyper-spatial and hyper-spectral imaging data-cube from the hyper-spatial and low-spectral imaging data-cube based on the hyper-spectral data-set. A terahertz spectral imaging apparatus is further provided.

Method and apparatus for processing terahertz spectral imaging data

An amphibious portable magnetism detector includes a first housing, a first wiring tube, a first magnetic field sensor, and a central control device. The first housing defines a first inner space and a first through hole in communication with the first inner space. The first wiring tube is connected to the first housing with a first leak-tight seal formed between them, and in communication with the first inner space via the first through hole. The first magnetic field sensor is disposed in the first inner space and configured to detect a magnetic field at a target area and generate a first detection signal. The central control device is electrically connected to the first magnetic field sensor and configured to receive the first detection signal and output a first magnetic field value according to the first detection signal.

Amphibious portable magnetism detector

The present application provides a terahertz spectral imaging data reconstruction method, an apparatus, a device, and a storage medium. The method includes: scanning a target object according to the first spatial interval and the first time domain sampling period to acquire the first terahertz spectral data; scanning the target object according to the second spatial interval and the second time domain sampling period to acquire the second terahertz spectral data, the first spatial interval is larger than the second spatial interval, and the first time domain sampling period is larger than the second time domain sampling period; and reconstructing the second terahertz spectral data on basis of the first terahertz spectral data by using the preset reconstruction method to obtain the third terahertz spectral data.

Terahertz spectral imaging data reconstruction method, apparatus, device, and storage medium

A gas detecting apparatus and a gas detecting method based on terahertz spectroscopy are provided. The apparatus includes a sample chamber allowing a terahertz wave to pass therethrough; a gas feeding unit connected to the sample chamber to feed gas into the sample chamber; a gas outputting unit connected to the sample chamber to output gas from the sample chamber; and a vacuum pump connected to the sample chamber to evacuate the sample chamber. The apparatus further comprises one or more of a pressure gauge disposed on the sample chamber, an anemometer disposed on the sample chamber, a humidity regulation device connected to the sample chamber, and a temperature regulation device connected to the sample chamber.

Gas detecting apparatus and method based on terahertz spectroscopy

The present disclosure provides a waveguide-excited terahertz microstrip antenna. The antenna includes a dielectric substrate, a ground plate, a rectangular waveguide, a metal pin, and a radiation patch. The dielectric substrate has a first surface and a second surface opposite to the first surface. The ground plate is located on the first surface of the dielectric substrate and defines a coupling slit. The rectangular waveguide is located on a surface of the ground plate away from the dielectric substrate and extended substantially along a first direction parallel to the first surface. The metal pin is located inside the rectangular waveguide, and is in contact with the ground plate and substantially perpendicular to the ground plate. The radiation patch is located on the second surface of the dielectric substrate.

Waveguide-excited terahertz microstrip antenna

A fluxgate detector for buried and abandoned chemical weapons is provided, comprising: a probe for sensing an external magnetic field, comprising a probe input and a probe output; an excitation module electrically connected to the probe input for inputting an excitation signal into the probe; a frequency selection module electrically connected to the probe output for isolating a second harmonic signal in an induced voltage generated by the probe; and a signal acquisition module electrically connected to the frequency selection module. The second harmonic signal in the induced voltage can be isolated by the frequency selection module, transmitted to the signal acquisition module, and converted to an intensity of the magnetic field by the signal acquisition module. The substance detected can be identified according to the intensity of the magnetic field, so that the buried ACWs can be found efficiently and accurately.

Fluxgate detector for buried and abandoned chemical weapons

The present application relates to a terahertz transmitting antenna including a microstrip feed line, a substrate, at least two antenna switches, at least one conducting plate, an insulating layer and at least two antenna patches. The terahertz transmitting antenna is provided with at least two antenna switches and at least two corresponding antenna patches, which substantially increases a transmitting bandwidth and a corresponding transmitting power of the terahertz transmitting antenna. The terahertz transmitting antenna with the increased transmitting bandwidth and the increased transmitting power can be applied to a small sized terahertz spectral detection device to assist the transmitting source to transmit the signal in the terahertz band. The terahertz transmitting antenna adopting the multi-frequency switching technology can reduce an operation time of a spectral fingerprint recognition algorithm to rapid identify specific target substances.

Terahertz antenna based on multi-frequency transmission switching and spectral detection device thereof

A cesium optical pump detector for buried and abandoned chemical weapons of Japan is provided, comprising a pumping light generation module, a first optical module, a magnetic resonance module, a photoelectric detection module, and a signal processing module. The signal processing module includes an amplifying and filtering unit, a self-oscillation unit, a measuring unit, and a calculating unit connected in sequence. The amplifying and filtering unit comprises a first band-pass filter configured to coarsely measure a frequency of the electrical signal and a second band-pass filter configured to finely measure the frequency of the electrical signal. The self-oscillation unit comprises a first phase shifter connected to the first band-pass filter and a second phase shifter connected to the second band-pass filter. In the present disclosure, the intensity of a magnetic field detected can be finely measured, so that the ACWs can be found efficiently and accurately.

Cesium optical pump detector for buried and abandoned chemical weapons

The present disclosure relates to a terahertz-based high-risk chemical detecting device, which includes a terahertz wave generating unit, a terahertz wave transmitting and receiving unit and an echo analysis unit. The terahertz wave generating unit is configured for generating a terahertz detection signal, a terahertz reference signal and a terahertz local oscillation signal. The terahertz wave transceiver unit is configured to transmit the terahertz detection signal and the terahertz reference signal to a high-risk chemical to be tested, and receive information about carrying a high-risk chemical to be tested. The terahertz echo signal is configured to analyze the terahertz echo signal and the terahertz local oscillation signal to obtain information about a high-risk chemical to be tested. The present disclosure also relates to a terahertz-based high-risk chemical detecting method.

Terahertz gas detection method and device based on Gregory double reflection antenna

The disclosure relates to a method and a system for terahertz ISAR imaging. In the method, a chirp signal is transmitted to an imaging target moving at a preset speed and a terahertz ISAR echo signal is received. The terahertz ISAR echo signal is matched filtered in a fast time domain, baseband transformed in a slow time domain, corrected to eliminate a time domain zero offset, baseband transformed, discretized, interpolated, and two-dimensional inverse Fourier transformed to obtain a two-dimensional image of the imaging target.

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Beijing, China

Xiao-Ping Zheng