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Article List
2022, 20(2):97-105.
DOI: 10.11805/TKYDA2021126
Abstract:
Global Navigation Satellite System(GNSS)-based passive radar is a hotspot of current research. In the positioning method based on the sum of distance, the time synchronization error and positioning error of GNSS will reduce the positioning accuracy. Considering the above errors and combining the signal characteristics and parameter measurement capabilities of the four major GNSSs in the world, the three-dimensional localization accuracy expressions and the Cramer-Rao Lower Bound(CRLB) for the system of multi-transmit multi-receive are derived. Through simulation analysis, the relationship between the number of satellites or receiving stations and the localization accuracy is revealed. When the satellite position errors are ignored, the percentage increases in localization accuracy caused by the number increases of receiving stations are the fixed values for any number of radiation sources; if the satellite position errors increase, the improvement in positioning accuracy by increasing the number of receiving stations will decrease. The obtained conclusions can provide a theoretical reference for the selection of GNSS-based passive radar radiation sources and the deployment of receiving stations.
Global Navigation Satellite System(GNSS)-based passive radar is a hotspot of current research. In the positioning method based on the sum of distance, the time synchronization error and positioning error of GNSS will reduce the positioning accuracy. Considering the above errors and combining the signal characteristics and parameter measurement capabilities of the four major GNSSs in the world, the three-dimensional localization accuracy expressions and the Cramer-Rao Lower Bound(CRLB) for the system of multi-transmit multi-receive are derived. Through simulation analysis, the relationship between the number of satellites or receiving stations and the localization accuracy is revealed. When the satellite position errors are ignored, the percentage increases in localization accuracy caused by the number increases of receiving stations are the fixed values for any number of radiation sources; if the satellite position errors increase, the improvement in positioning accuracy by increasing the number of receiving stations will decrease. The obtained conclusions can provide a theoretical reference for the selection of GNSS-based passive radar radiation sources and the deployment of receiving stations.
2022, 20(2):147-153.
DOI: 10.11805/TKYDA2021325
Abstract:
There are contradictions between similarity and particularity when simulating the signal and data processing of different radar systems. Based on the component design, radar signal and data processing are divided into 28 components including antenna simulation, target echo power calculation, pulse compression, parameter measurement, trajectory start, tracking filter, scheduling strategy and so on. By choosing the parameter of radar type, the particularity radar function can be simulated. Meanwhile, the components of similarity radar function are reusable so that the phased array radar, mechanical scanning radar and passive radar are simulated in functional level. The components are tested to verify the effectiveness of the component design method.
There are contradictions between similarity and particularity when simulating the signal and data processing of different radar systems. Based on the component design, radar signal and data processing are divided into 28 components including antenna simulation, target echo power calculation, pulse compression, parameter measurement, trajectory start, tracking filter, scheduling strategy and so on. By choosing the parameter of radar type, the particularity radar function can be simulated. Meanwhile, the components of similarity radar function are reusable so that the phased array radar, mechanical scanning radar and passive radar are simulated in functional level. The components are tested to verify the effectiveness of the component design method.
2022, 20(2):154-158.
DOI: 10.11805/TKYDA2020684
Abstract:
Huynen Target Parameters(HTPs) and Optimum Polarizations(OPs) are two fundamental concepts in the polarization information processing field. According to the characteristic angle of HTPs, the graphical representation of OPs can be divided into three classes, needle shape, top shape, and the well-known fork shape, which has not been sufficiently discussed before. In this paper, OPs are derived based on the Kennaugh matrix. Then, the relationship between HTPs and OPs is revealed. On the basis of that, the polarization scattering characteristics of several typical structures are investigated. This paper aims to establish a clear concept about HTPs and OPs for radar polarimetry researchers.
Huynen Target Parameters(HTPs) and Optimum Polarizations(OPs) are two fundamental concepts in the polarization information processing field. According to the characteristic angle of HTPs, the graphical representation of OPs can be divided into three classes, needle shape, top shape, and the well-known fork shape, which has not been sufficiently discussed before. In this paper, OPs are derived based on the Kennaugh matrix. Then, the relationship between HTPs and OPs is revealed. On the basis of that, the polarization scattering characteristics of several typical structures are investigated. This paper aims to establish a clear concept about HTPs and OPs for radar polarimetry researchers.
2022, 20(2):119-126.
DOI: 10.11805/TKYDA2021341
Abstract:
Netted radar data fusion processing has the characteristics of wide application scenes, adopting diverse algorithms and using controllable parameters. Aiming at the problems of long development cycle and high system design complexity existing in the development of traditional fusion processing system, based on the component design of fusion processing, a general template of network fusion processing is designed by using open and reconfigurable architecture. Because of the low coupling of components, the system can be expanded easily only by modifying some components instead of building a whole system. The expanded contents include new component algorithms and new fusion templates. Compared with reconstructing the whole system, the independent and easy-to-understand component expansion operation reduces the complexity of the system and the ability requirements for developers. Simulation experiments have achieved two types of expansion. The results show that the design is feasible, improves the integration efficiency of the new algorithm, and enhances the scene adaptability of the networked fusion processing system.
Netted radar data fusion processing has the characteristics of wide application scenes, adopting diverse algorithms and using controllable parameters. Aiming at the problems of long development cycle and high system design complexity existing in the development of traditional fusion processing system, based on the component design of fusion processing, a general template of network fusion processing is designed by using open and reconfigurable architecture. Because of the low coupling of components, the system can be expanded easily only by modifying some components instead of building a whole system. The expanded contents include new component algorithms and new fusion templates. Compared with reconstructing the whole system, the independent and easy-to-understand component expansion operation reduces the complexity of the system and the ability requirements for developers. Simulation experiments have achieved two types of expansion. The results show that the design is feasible, improves the integration efficiency of the new algorithm, and enhances the scene adaptability of the networked fusion processing system.
2022, 20(2):133-139.
DOI: 10.11805/TKYDA2021332
Abstract:
There are many problems faced by cognitive Electronic Warfare (EW) equipment, including complex and diverse combat scenes, being difficult to obtain real data and high cost of actual combat training. In order to meet the needs of scheme demonstration and key technology research, by combining artificial intelligence with system simulation technology, the signal level model of cognitive EW equipment and its typical combat objects is established. The information interaction process between EW equipment and combat objects in complex electromagnetic environment is simulated. A learning training and simulation evaluation system for future battlefield cognitive confrontation is built. The function, architecture, workflow and key modules/models of the system are introduced in detail. The application examples of the system are analyzed. According to the application effect, the system can provide guidance for intelligent algorithm model training of cognitive EW and the simulation test evaluation on equipment combat capability.
There are many problems faced by cognitive Electronic Warfare (EW) equipment, including complex and diverse combat scenes, being difficult to obtain real data and high cost of actual combat training. In order to meet the needs of scheme demonstration and key technology research, by combining artificial intelligence with system simulation technology, the signal level model of cognitive EW equipment and its typical combat objects is established. The information interaction process between EW equipment and combat objects in complex electromagnetic environment is simulated. A learning training and simulation evaluation system for future battlefield cognitive confrontation is built. The function, architecture, workflow and key modules/models of the system are introduced in detail. The application examples of the system are analyzed. According to the application effect, the system can provide guidance for intelligent algorithm model training of cognitive EW and the simulation test evaluation on equipment combat capability.
2022, 20(2):106-118.
DOI: 10.11805/TKYDA2021310
Abstract:
With the development of synchronization and high-performance computing technologies, the four advantages of bistatic/multi-static radar systems on anti-jamming, anti-destruction, anti-stealth targets, and anti-low-altitude target invasion have been gradually coming true. The bistatic/multi-static radar systems have attracted great attention. The bistatic scattering characteristics on Radar Cross-Section(RCS),scattering center,and polarization are quite different from the monostatic radar. Only baed on the detailed understanding of bistatic scattering characteristics, ?the bistatic/multi-static radar potentials in target detection,feature extraction,and target recognition can be fully exploited. The issue of bistatic scattering characteristics is one of the urgent problems waiting to be investigated. This paper reviews the newest development of bistatic scattering characteristics and attempts to guide future research on bistatic radar.
With the development of synchronization and high-performance computing technologies, the four advantages of bistatic/multi-static radar systems on anti-jamming, anti-destruction, anti-stealth targets, and anti-low-altitude target invasion have been gradually coming true. The bistatic/multi-static radar systems have attracted great attention. The bistatic scattering characteristics on Radar Cross-Section(RCS),scattering center,and polarization are quite different from the monostatic radar. Only baed on the detailed understanding of bistatic scattering characteristics, ?the bistatic/multi-static radar potentials in target detection,feature extraction,and target recognition can be fully exploited. The issue of bistatic scattering characteristics is one of the urgent problems waiting to be investigated. This paper reviews the newest development of bistatic scattering characteristics and attempts to guide future research on bistatic radar.
2022, 20(2):140-146.
DOI: 10.11805/TKYDA2021327
Abstract:
In order to improve the reality of false-target image in deception jamming against Inverse Synthetic Aperture Radar(ISAR), the signal modeling of two-dimensional decoys in Self-Screening Jamming(SSJ) scenarios with controllable position is studied based on the modulation template in scattering center model. Firstly, the time delay in the fast time domain corresponding to the longitudinal modulated coordinates and offsets can control the position of the false target in the down range. Secondly, the phase modulating coefficient in the slow time domain corresponding to the transverse modulated coordinates and offsets can control the position in the cross range. Thirdly, the modulated speed would cause horizontal extension or compression of the false-target image. The simulation results verify the correctness of the theoretical analysis and demonstrate the effectiveness of the proposed jamming method, and it also has low power requirement.
In order to improve the reality of false-target image in deception jamming against Inverse Synthetic Aperture Radar(ISAR), the signal modeling of two-dimensional decoys in Self-Screening Jamming(SSJ) scenarios with controllable position is studied based on the modulation template in scattering center model. Firstly, the time delay in the fast time domain corresponding to the longitudinal modulated coordinates and offsets can control the position of the false target in the down range. Secondly, the phase modulating coefficient in the slow time domain corresponding to the transverse modulated coordinates and offsets can control the position in the cross range. Thirdly, the modulated speed would cause horizontal extension or compression of the false-target image. The simulation results verify the correctness of the theoretical analysis and demonstrate the effectiveness of the proposed jamming method, and it also has low power requirement.
2022, 20(2):127-132.
DOI: 10.11805/TKYDA2021336
Abstract:
In order to improve the efficiency of radar system simulation, a component-based method for constructing signal processing module of radar simulation system is proposed in this paper. Firstly, a library of signal processing function components is established based on the independence of the different functions of radar signal processing for the proposed method; on this basis, the required signal processing modules can be flexibly constructed by selecting and splicing components after analyzing the simulated radar; finally, the effectiveness of the proposed method is demonstrated by the experiment through the radar componentized signal processing module constructed in Visual Studio 2013 platform.
In order to improve the efficiency of radar system simulation, a component-based method for constructing signal processing module of radar simulation system is proposed in this paper. Firstly, a library of signal processing function components is established based on the independence of the different functions of radar signal processing for the proposed method; on this basis, the required signal processing modules can be flexibly constructed by selecting and splicing components after analyzing the simulated radar; finally, the effectiveness of the proposed method is demonstrated by the experiment through the radar componentized signal processing module constructed in Visual Studio 2013 platform.
2022, 20(3):200-207.
DOI: 10.11805/TKYDA2021344
Abstract:
In order to verify the effect of Unmanned Aerial Vehicle(UAV) cluster electronic countermeasures, the influence mechanism of cluster ontology, cluster suppression interference, cluster retransmitting interference, and cluster coherent interference on multi-radar parameter measurement is discussed. The influencing factors such as Signal-Noise Ratio(SNR), Jamming-Signal Ratio(JSR), and the amplitude ratio between target echo and UAV body echo are analyzed emphatically. Firstly, the UAV jamming resources are allocated based on the greedy algorithm, and then the influence of several jamming methods on the measurement of radar parameters is analyzed through simulation. The experimental results show that the cluster body has a small effect on the radar, mainly due to the small size of the UAV and the low echo power; the cluster suppression interference increases the detection threshold, which greatly reduces the target detection probability of multiple radars; retransmitting interference can produce a large number of false targets, leading to larger errors in radar angle measurement; cluster coherent interference can cause radar angle measurement to deviate from the direction of the main beam, forming angle deception. Comprehensive analysis shows that the three interference methods, suppression interference, retransmitting interference and coherent interference, have good interference effects when applied in cluster interference.
In order to verify the effect of Unmanned Aerial Vehicle(UAV) cluster electronic countermeasures, the influence mechanism of cluster ontology, cluster suppression interference, cluster retransmitting interference, and cluster coherent interference on multi-radar parameter measurement is discussed. The influencing factors such as Signal-Noise Ratio(SNR), Jamming-Signal Ratio(JSR), and the amplitude ratio between target echo and UAV body echo are analyzed emphatically. Firstly, the UAV jamming resources are allocated based on the greedy algorithm, and then the influence of several jamming methods on the measurement of radar parameters is analyzed through simulation. The experimental results show that the cluster body has a small effect on the radar, mainly due to the small size of the UAV and the low echo power; the cluster suppression interference increases the detection threshold, which greatly reduces the target detection probability of multiple radars; retransmitting interference can produce a large number of false targets, leading to larger errors in radar angle measurement; cluster coherent interference can cause radar angle measurement to deviate from the direction of the main beam, forming angle deception. Comprehensive analysis shows that the three interference methods, suppression interference, retransmitting interference and coherent interference, have good interference effects when applied in cluster interference.
2022, 20(3):235-240.
DOI: 10.11805/TKYDA2021353
Abstract:
Multi-expert evaluation, as a traditional and effective method to evaluate the anti-jamming capability of radar systems, has the disadvantages of inaccurate evaluation caused by differences of expert levels and individual preferences. In this paper, by combining Analytic Hierarchy Process(AHP) with Principal Component Analysis(PCA), an AHP-PCA method is proposed to ensure the consistency of multi-expert group decision-making. The comprehensive results about the anti-jamming capability of the seeker system in the same environment are obtained through the application of AHP-PCA to the anti-jamming capability evaluation of radar seekers. Then the consistency of the group decision on the comprehensive evaluation results is described quantitatively. The evidences suggest that the AHP-PCA method can reduce the impact of evaluation inaccuracy and the subjectivity of evaluation caused by different preferences of experts, and that AHP-PCA is of engineering application value.
Multi-expert evaluation, as a traditional and effective method to evaluate the anti-jamming capability of radar systems, has the disadvantages of inaccurate evaluation caused by differences of expert levels and individual preferences. In this paper, by combining Analytic Hierarchy Process(AHP) with Principal Component Analysis(PCA), an AHP-PCA method is proposed to ensure the consistency of multi-expert group decision-making. The comprehensive results about the anti-jamming capability of the seeker system in the same environment are obtained through the application of AHP-PCA to the anti-jamming capability evaluation of radar seekers. Then the consistency of the group decision on the comprehensive evaluation results is described quantitatively. The evidences suggest that the AHP-PCA method can reduce the impact of evaluation inaccuracy and the subjectivity of evaluation caused by different preferences of experts, and that AHP-PCA is of engineering application value.
2022, 20(3):218-227.
DOI: 10.11805/TKYDA2022002
Abstract:
The obtuse dihedral structure plays an important role in the stealth characteristics of the target, but its bistatic characteristics are still unclear. The method of combining electromagnetic simulation and statistical modeling is utilized to analyze its bistatic scattering characteristics from the perspective of frequency domain, space domain, polarization domain and statistical distribution. Studies have shown that when the electrical size is small, the bistatic scattering enhancement characteristics are not obvious, and the probability density distributions of monostatic/bistatic Radar Cross Section(RCS) are very different; the bistatic RCS probability density distribution of co-polarization exhibits bimodal characteristics. For this reason, the Bimodal Lognormal Distribution Model(BLDM) is proposed. This distribution model has achieved an ideal fitting effect. When the electrical size is large, the co-polarized bistatic forward scattering characteristics are significantly enhanced, and the monostatic/bistatic RCS probability density distributions are similar, which conforms to the lognormal distribution and the chi-square distribution. The law revealed has reference significance for the utilization and detection of obtuse dihedral structures.
The obtuse dihedral structure plays an important role in the stealth characteristics of the target, but its bistatic characteristics are still unclear. The method of combining electromagnetic simulation and statistical modeling is utilized to analyze its bistatic scattering characteristics from the perspective of frequency domain, space domain, polarization domain and statistical distribution. Studies have shown that when the electrical size is small, the bistatic scattering enhancement characteristics are not obvious, and the probability density distributions of monostatic/bistatic Radar Cross Section(RCS) are very different; the bistatic RCS probability density distribution of co-polarization exhibits bimodal characteristics. For this reason, the Bimodal Lognormal Distribution Model(BLDM) is proposed. This distribution model has achieved an ideal fitting effect. When the electrical size is large, the co-polarized bistatic forward scattering characteristics are significantly enhanced, and the monostatic/bistatic RCS probability density distributions are similar, which conforms to the lognormal distribution and the chi-square distribution. The law revealed has reference significance for the utilization and detection of obtuse dihedral structures.
2022, 20(3):228-234.
DOI: 10.11805/TKYDA2021314
Abstract:
As the typical signal of Aegis radar, the intra-pulse multi-carrier frequency signal has awesome advantages of anti-interception and anti-jamming. However, its signal processing method is unclear. Taking the intra-pulse four-carrier frequency signal as an example, its signal characteristics and processing methods are studied. Based on the principle of optimal detection probability, the possible processing methods are proposed, and the processing framework and process are given. Especially for the case of aiming interference, the interference detection algorithm is employed to eliminate the interfered sub pulses. The detection performance of the two processing methods in different scenarios is compared through signal level simulation. The conclusion provides a reference for the processing and application of intra-pulse multi-carrier frequency signal.
As the typical signal of Aegis radar, the intra-pulse multi-carrier frequency signal has awesome advantages of anti-interception and anti-jamming. However, its signal processing method is unclear. Taking the intra-pulse four-carrier frequency signal as an example, its signal characteristics and processing methods are studied. Based on the principle of optimal detection probability, the possible processing methods are proposed, and the processing framework and process are given. Especially for the case of aiming interference, the interference detection algorithm is employed to eliminate the interfered sub pulses. The detection performance of the two processing methods in different scenarios is compared through signal level simulation. The conclusion provides a reference for the processing and application of intra-pulse multi-carrier frequency signal.
2022, 20(3):292-296.
DOI: 10.11805/TKYDA2020184
Abstract:
Multipath routing is essential to overcome the high loss rate in Wireless Sensor Networks(WSNs). Current proposals rely on centralized computation or iterative distributed algorithms and consume large amount of convergence time. Therefore, Exploration Packet-based Multipath Routing(EPMR) is proposed in this paper. EPMR routing first collects local topology information by using the transmission of exploration packets. According to the arrival time of the received exploration packet, the port priority is set, and the node that gives priority to the port priority participates in the route. Once participating in a path, the node will no longer participate in other paths between the source node and the destination node pair, thus ensuring the disjunction between multiple paths. Simulation results show that the proposed EPMR improves the packet transmission success rate and cuts the running time.
Multipath routing is essential to overcome the high loss rate in Wireless Sensor Networks(WSNs). Current proposals rely on centralized computation or iterative distributed algorithms and consume large amount of convergence time. Therefore, Exploration Packet-based Multipath Routing(EPMR) is proposed in this paper. EPMR routing first collects local topology information by using the transmission of exploration packets. According to the arrival time of the received exploration packet, the port priority is set, and the node that gives priority to the port priority participates in the route. Once participating in a path, the node will no longer participate in other paths between the source node and the destination node pair, thus ensuring the disjunction between multiple paths. Simulation results show that the proposed EPMR improves the packet transmission success rate and cuts the running time.
2022, 20(3):195-199.
DOI: 10.11805/TKYDA2021339
Abstract:
Forward scattering radar is a particular bistatic radar scheme with the bistatic angle approaching 180°. According to the total field variation, the forward scattering radar can detect the target when targets pass through the baseline. Therefore, the research on echo characteristics of forward-scattering radar is of great significance. The effects of coherent superposition of scattering and radiation fields are analyzed based on the measurement data of metallic sphere, dihedral, trihedral, and cylinder radar targets in an anechoic chamber. It is summarized that when the radar target enters the forward scattering zone, the echo amplitude decreases firstly, and then rebounds slightly. This work helps to improve the knowledges about forward-scattering radar echo characteristics, and provides supports for the target detection and recognition technologies.
Forward scattering radar is a particular bistatic radar scheme with the bistatic angle approaching 180°. According to the total field variation, the forward scattering radar can detect the target when targets pass through the baseline. Therefore, the research on echo characteristics of forward-scattering radar is of great significance. The effects of coherent superposition of scattering and radiation fields are analyzed based on the measurement data of metallic sphere, dihedral, trihedral, and cylinder radar targets in an anechoic chamber. It is summarized that when the radar target enters the forward scattering zone, the echo amplitude decreases firstly, and then rebounds slightly. This work helps to improve the knowledges about forward-scattering radar echo characteristics, and provides supports for the target detection and recognition technologies.
