Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.