Modern Defense Technology

Research on Tracking and Prediction Technology of Near Space Target

LI Jun-long, ZHOU Di, WANG Guan, CHEN Xiao-bo, QIN Lei

2021, 49(3): 1-12. doi:10.3969/j.issn.1009-086x.2021.03.001

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With the rapid development of near space hypersonic vehicle,tracking and prediction technology of near space target has attracted wide attention.The main tracking and prediction technologies of near space target are discussed,such as the model of near space hypersonic maneuvering target,the design method of multi-model filter,the trajectory prediction method of near space hypersonic maneuvering target,etc.The main problems of existing methods are pointed out,and the main research directions are given.

Analysis on the Operation of Attack and Defense of UAVs in Naka Conflict and Suggestions for Ground-to-Air Anti-UAVs

WU Jing, CAI Hai-feng, LIU Jun-liang

2021, 49(3): 13-20. doi:10.3969/j.issn.1009-086x.2021.03.002

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Many kinds of UAVs were used throughout the conflict in Nagorno-Karabakh in 2020.The UAVs strike a lot of tactical targets,and play an important role in effecting on battlefield situation.By analyzing the main UAVs' performance of Azerbaijan,the operational mode and typical attack and defense cases are analyzed.The suggestion for capability demand on ground-to-air anti-UAVs is provided based on the reason of failure in Armenia anti-air operation.This conclusion supports development and operation of ground-to-air anti-UAVs equipment.

Evaluation Method of Technical Contribution Rate of U.S. Aircraft Carrier Combat System-of-Systems Considering the Influence of Time and Space

CHEN Qiu-li, LUO Cheng-kun, LIU Ying, ZHANG Yang-ming

2021, 49(3): 21-29. doi:10.3969/j.issn.1009-086x.2021.03.003

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Aiming at the current evaluation methods of technical contribution rate are mostly based on static combat networks with low credibility of the evaluation results,an evaluation method of technical contribution rate of U.S. aircraft carrier combat system-of-systems considering the influence of time and space is proposed.The U.S. aircraft carrier combat network model considering time and space factors is constructed based on OODA (observation,orientation,decision,action) operation loop.The effectiveness evaluation method of combat system-of-systems based on self-information is proposed. Combining the degree of technical support for equipment combat technical indicators, an evaluation model of technical contribution rate is established.Taking the air defense and anti-missile combat system-of-systems of the U.S. aircraft carrier as an example,the results show that the proposed method fully takes into account the spatial-temporal dynamic characteristics of the combat network,which can assess the contribution rate of technology more realistically and objectively,and support for the equipment project approval demonstration and technology optimization development.

Research on Requirements of Unmanned Underwater Vehicles in Anti-Submarine Operations of Surface Vessels

QI Xue-wen, XIA Qing-feng, WANG Xiang

2021, 49(3): 30-37. doi:10.3969/j.issn.1009-086x.2021.03.004

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The military requirements of unmanned underwater vehicles are researched for unmanned underwater submarine vehicles can provide anti-submarine barrier for surface vessels.According to the characteristics of underwater threats of surface vessels,the basic requirements of unmanned underwater vehicles force allocation are put forward.Based on the analysis of maneuver elements of both sides,submarine attack position line and the latest warning line of unmanned underwater vehicles are defined,and the expressions are derived through analytical calculation to obtain the perimeter of the latest warning line of unmanned underwater vehicles and estimate the minimum number required of unmanned underwater vehicle.According to the modeling and analytical calculation process,the affecting factors of the minimum number required of unmanned underwater vehicle are analyzed,and the sensitivity of each factor is quantitatively simulated.According to the results,6 influencing factors are divided into 4 levels.Suggestions are put forward on carrying scheme design and performance design of shipborne unmanned underwater vehicles for large surface vessels. The results show that the models and methods proposed are feasible.

A Brief Analysis of U.S. Critical Infrastructure Electromagnetic Pulse Defense Policies

FENG Han-liang, XIA Liang-bin, WANG Juan, CUI Gang-qiang, ZHAO Rui, LIU Yan-sheng

2021, 49(3): 38-46. doi:10.3969/j.issn.1009-086x.2021.03.005

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At present,military equipment,systems and civil infrastructure are facing increasingly serious electromagnetic pulse (EMP) threat.The United States has been strengthening the assessment and defense of EMP threat.To fully un-derstand and analyze the current situation,problems and policies of EMP defense in the United States,the series of assessment reports issued by EMP Commission,the president executive order and important documents issued by the United States government such as “National Defense Authorization Act” are researched.The EMP threat environ-ment,scenes and responsive strategies in the United States,and the roles,responsibilities and tasks of relevant de-partments and heads of the federal government are analyzed.It is noted that the U.S. currently aims to ensure U.S. security by establishing strong national executive leadership,organizing and coordinating government and private sector relationships,and promoting technology information sharing to strengthen U.S. critical infrastructure and improve U.S. resilience to EMP threats.

Research on Establishment Method of Evaluation Index System for Operational Test of Warships

XU Qiang, JIN Zhen-zhong, YANG Ji-kun

2021, 49(3): 47-54. doi:10.3969/j.issn.1009-086x.2021.03.006

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There are some problems in the establishment of the evaluation index system for operational test of warships,such as unclear methods,unclear steps and low operability.The establishment method of evaluation index system for operational test of warships is studied,the general idea and process of index establishment is designed,“one effectiveness & three suitability” as related index system is carried out to build the basic framework.Based on the interpretive structural modeling (ISM) method,the complex hierarchical relationships of the index system are proposed to be integrated and optimized to form an assessment index system with scientific structure and reasonable content.

Research on Effectivess Evaluation Method of Anti-Ship Missile Weapon System Based on Fuzzy-ADC Model

YANG Jian-bo, ZONG Si-guang

2021, 49(3): 55-62. doi:10.3969/j.issn.1009-086x.2021.03.007

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How to effectively evaluate the effectiveness of anti-ship missile weapon system under the condition of confrontation is an important measure to improve the combat effectiveness of anti-ship missile weapon.Based on ADC model,the factors is comprehensively analyzed,characteristics and effectiveness indexes that affect the anti-ship missile combat capability system,and establishes the evaluation index system.Analytic hierarchy process (AHP) is used to determine the weight vector of each sub-index,and the fuzzy comprehensive evaluation is used to calculate the capability value of each sub-index.The capability value of each index is calculated by using the index method to establish combat effectiveness evaluation model of anti-ship missile weapon system.The sensitivity of different indicators is analyzed to the whole anti-ship missile weapon system,to provide reference for the future development and use of anti-ship missile.

Topology Optimization of Thermal Structure with Phase Change Materials

ZHANG Xiao-liang, YU Jiang-xiang, LIU Chang-hong

2021, 49(3): 63-72. doi:10.3969/j.issn.1009-086x.2021.003.008

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Aiming at the structure under thermal load,a thermal control scheme of delaying the temperature rise of the structure by introducing aluminum based phase change material is studied.Because of the strong nonlinearity of the heat conduction process with phase change,it is very difficult to calculate the sensitivity information.To overcome this problem,a topology optimization method of cross section considering heat conduction process with phase change and material temperature effect is proposed based on Kriging surrogate model optimization algorithm and MFSE (Material Field Series Expansion) topology description method with less design variables,which takes the weight as the constraint and the maximum bending rigidities as the objective.Two kinds of aluminum based phase change materials are studied,the material distribution form with the largest bending rigidities under thermal load is obtained.The analysis of the optimal configuration shows that the addition of aluminum based phase change material in the section of TA15 stiffeners can effectively prolong the working time of the stiffeners in high temperature environment.

Tactical Intention Recognition Based on Operation Knowledge Neural Network

LIU Qiu-hui, CHONG Yuan

2021, 49(3): 73-79. doi:10.3969/j.issn.1009-086x.2021.03.009

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Tactical intention recognition provides decision support for commanders to understand the battlefield posture and develop the plan operations.How to structure intention recognition is a challenging problem in situation analysis.Aiming at the integration and transmission of battlefield situational uncertainty in traditional tactical intent recognition methods and the solidification of inference templates,a target tactical intent inference framework is constructed based on the acquisition of dynamic operational knowledge of the target for explaining the operational elements in the course of enemy combat operations.Based on the characteristics of combat plan,a target tactical intention recognition method based on operational knowledge neural network (OKNN) is proposed. OKNN takes the air target group as the unit and enhances the flexibility of model reasoning by dynamically building a set of entity fragments based on operational knowledge in real time.The model is based on an empirical training sample plan library,which can dynamically and adaptively adjust the spatial distribution of target tactical intent results,greatly eliminating the integration and transmission of uncertainty.The simulation results indicate that the reasoning model is feasible and effective.

Study on the Extinction Characteristics of Smoke Jamming in Spacecraft

ZHANG Lei

2021, 49(3): 80-85. doi:10.3969/j.issn.1009-086x.2021.03.010

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Based on MIE scattering theory,the radiative transfer model of absorption,emission and scattering particle system in space environment is established.The change of total radiation in smoke diffusion process is studied,and the infrared stealth effect of particle optical properties,particle number density and smoke thickness on the whole smoke shielding is analyzed.The results show that the medium wave can provide a better stealth effect,and can mask up to 90% of the vehicle radiation.The refractive index of particles has little effect on the smoke stealth effect,and the absorption index has a greater effect on the smoke stealth effect;the particle size has a greater impact on the stealth effect,and there is an optimal particle size selection under the specific optical properties.The density of smoke has a saturation value,when the saturation value is exceeded,the stealth effect will not increase,and the thickness of smoke screen has no obvious improvement on the stealth effect.

Demand and Application of Active Countermeasure Technology for Ground Military Vehicle

YU Hui-juan, WEI Xue-zhong, LIU Xiang-xin, LI Lan

2021, 49(3): 86-91. doi:10.3969/j.issn.1009-086x.2021.03.011

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The survival of ground military vehicle is prerequisite for the weapons battle effectiveness in attack and defense.The advanced survival technology is core for weapon system.With the continuous upgrading of real-time reconnaissance and precise guidance in the battlefield,the active countermeasure technology is proposed to against discovery,identification,tracking and fight threats based on passive protection technology.The development of active countermeasure technology at home and abroad is analyzed.The active countermeasure technology strategy and approach are discussed,and the application prospect and development idea of the active countermeasure technology of ground military vehicle are researched,including improving top-level design and equipment demonstration of ground military vehicle survival in the future.

SAR Image Segmentation Algorithm Based on PCNN and Edge Detection

WANG Bin, WANG Guo-yu

2021, 49(3): 92-97. doi:10.3969/j.issn.1009-086x.2021.03.012

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Aiming at the problem that the target in high-resolution SAR image is complex,has serious coherent speckle noise, and the gray level fluctuates violently leading to blurred edges of the target for accurate segmentation,a high-resolution SAR image segmentation algorithm based on Riesz fractional Derived (RFD) edge detection and pulse coupled neural network (PCNN) in fractional Fourier transform (FrFT) domain is proposed.The original image is processed by edge detection to retain better edge information,and then the image is segmented by the PCNN model.The coherent spots are further removed by morphology.The proposed algorithm is applied to high-resolution SAR image segmentation in different regions,and the experimental results show that it can effectively suppress the influence of speckle noise and gray boundary-blurring,and achieve an accurate segmentation effect.

A Modulation Recognition Algorithm for UAV Emitter

HUANG Xiang, XU Jing, DU Chen, GUO Zhao-yi, WU Tao

2021, 49(3): 98-104. doi:10.3969/j.issn.1009-086x.2021.03.013

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Aiming at the problem of small UAVs threatening the low-altitude field and its difficulty in recognition under complex electromagnetic environment, a signal recognition algorithm based on convolutional neural network (CNN) is proposed.The characteristics of the direct sequence spread spectrum (DSSS) signal under the application of UAVs are analyzed,and the signal time-frequency characteristics are obtained by short-time Fourier transform (STFT).The energy threshold noise reduction method proposed is used to reduce the noise in the time-frequency features.The CNN is designed for classification and recognition.Simulation results show that the algorithm has strong robustness and low signal-to-noise ratio environmental adaptability,and its performance is significantly better than traditional algorithms.When the signal-to-noise ratio (SNR) is -6 dB,the recognition rate reaches 0.97.

Weak Moving Target Detection Based on Second-Order Keystone Transform

ZHAI Xin-die, YANG Gang, LIAN Jie

2021, 49(3): 105-114. doi:10.3969/j.issn.1009-086x.2021.03.014

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Radar technology was developed to detect distant targets.The missile-borne radar processes echo signals to achieve the speed measurement and ranging of moving targets.The “long distance,low observable and high speed maneuvering” of weak moving targets make it difficult for traditional detection methods to identify,detect and track them.In order to improve the detection ability of such targets,signals are often be integrated.However,due to the movement of the target,the across range unit effect and Doppler frequency migration effect will be produced in the long-time integration of signal.The echo model construction of rectilinearly moving targets with uniform velocity and acceleration is studied,and the items that cause the ARU (across range unit) effect are analyzed.To analyzed the effect of the range walk compensation,the simulation of first-order and second-order Keystone algorithm is compared.The CZT-IFFT (Chirp-Z transformation-inverse fast fourier transform) method is selected to realize the second-order Keystone algorithm,correcting the range curvature and range walking,and the signal-to-noise ratio gain of different correction methods are compared.

Spectral Images Compressive Sampling Detection Based on Prior Sparse Model

LI Xiao-fei, TANG Yi-dong

2021, 49(3): 115-122. doi:10.3969/j.issn.1009-086x.2021.03.015

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The compressive signal processing provides an effective approach for efficient spectral image data collecting and processing.An improved compressive sampling detection method based on prior sparse model of signal is proposed to solve the problems of low detection rate and weak robustness in traditional compressive sampling detection algorithm.To enhance the capability of information collection,the sparse representation subspace of signal to be measured is used to design compressive sampling matrix.The orthogonal subspace projection method is used to project the compressive sampling signal into the local orthogonal subspace of the interfering signal for background suppression.The experimental and analytical results show that the method can effectively improve the performance of the compressive sampling detection compared with the traditional algorithm,and enhance the robustness for different sample matrix.

Comprehensive Evaluation Method of Missile′s Natural Environment Adaptability

LIU Yan, LIU Yi, CHEN Jiang-pan, ZHANG Wei-wen, SUN Li-min, WANG Dong

2021, 49(3): 123-129. doi:10.3969/j.issn.1009-086x.2021.03.016

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The long term natural environment adaptability of missile cannot be evaluated completely in the short term due to the low degeneration of natural environmental effects,though extremely limited environmental tests have been carried out in the missile laboratory in response to various environmental factors in the natural environment.A set of comprehensive evaluation methods is provided for long-term natural environmental effects,which defines the natural environment adaptability verification method for different types of missile products.Through the comprehensive utilization of the basic data of natural environment adaptability and various test verification information,the systematic,comprehensive and rapid evaluation of the missile's natural environment adaptability is realized.

Radar Radiation Source Identification Based on Convolution Neural Network

NIU Hao-nan, WANG Wen-can, LIU Qing-bo

2021, 49(3): 130-136. doi:10.3969/j.issn.1009-086x.2021.03.017

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As the electromagnetic environment becomes more and more complex and changeable,it brings great challenges to electronic countermeasures.The traditional pulse description and signal recognition methods cannot meet the requirements of the battlefield.Aiming at the problem of accurate identification of radiation sources in complex electromagnetic environments,the phased array radar emitter is moded based on its microscopic features such as envelope and phase noise characteristics.A method for individual identification of radar radiation sources based on radar IF data and one-dimensional convolutional neural networks is proposed in combination with convolutional neural networks.A one-dimensional convolutional neural network is trained to learn and identify the effective features of radar radiation source signals.The recognition simulation experiments are conducted under different signal-to-noise ratio conditions with high recognition correct rates,which proves the effectiveness and feasibility of the method.

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