Modern Defense Technology

An Real-time Estimation Algorithm for Slope Error of Radome of Radar Seeker

ZHOU Di, LI Jun-long, YUAN Yu-qi

2020, 48(5): 1-9. doi:10.3969/j.issn.1009-086x.2020.05.001

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Firstly, a complete mathematical description of target missile relative motion problem, which consider the slope error of seeker radome is established,including nonlinear state equation and measurement equation.Secondly,the simplified mathematical model of target missile relative motion considering radome error slope in the elevation channel isgiven,and the mathematical model of joint estimation of line-of-sight rate and radome error slope in the elevation channel is derived.The observability of the joint observation system of line-of-sight rate and radome error slope corresponding to the above mathematical model is proved.Finally,an extended Kalman filter is designed to estimate the line-of-sight rate and radome error slope in the elevation loop and azimuth loop,respectively.The filters are applied in the simulation experiments and compared with the Kalman filter of line-of-sight rate estimation without considering the error slope of radome.The simulation results show that the extended Kalman filter with joint estimation of line-of-sight rate and radome error slope is effective,since it can significantly improve the guidance accuracy of a guidance system with radome error slope.

Analysis on the Technical Approaches of Medium/Small Unmanned Aerial Vehicle Against Laser Weapon

XU Ming-xing, LIN Bing-xuan, CHEN Zhi-gang, WANG Wen-zheng, SHEN Yan-ming

2020, 48(5): 10-15. doi:10.3969/j.issn.1009-086x.2020.05.002

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As high-powered laser weapons continue to mature,the battlefields faced by medium/small unmanned aerial vehicle (UAV) are increasingly threatened.In order to further improve the battlefield survivability of medium/small UAV,it is necessary to study the strategies of medium/small UAV to defend high-powered laser weapons.Firstly,analyzes the current development trend of high-energy laser weapons;secondly,gives the composition and operational principles of high-energy laser weapons.On this basis,the constraints imposed on the application of high-energy laser weapons in battlefields are analyzed.Finally,a targeted strategy is proposed for medium/small UAV against high-powered laser weapons,and the key technology paths for implementing these strategies are analyzed.

Introduction to the Defense Acquisition System of U.S.A.

ZONG Kai-bin, ZHANG Cheng-long, ZHUO Zhi-min

2020, 48(5): 16-24. doi:10.3969/j.issn.1009-086x.2020.05.003

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As a typical representative of defense acquisition,equipment acquisition usually involves large amount of processes in execution.Meanwhile,due to the advancement requirements of the equipment,its realization must rely on the effective integration of advanced scientific and technological achievements in many fields.Therefore,the impacts of technological maturity and manufacturing maturity on acquisition programs must be considered.For ensuring the success of acquisitions and managing the implementation effectively,the department of defense has proposed defense acquisition system based on system engineering methodologies,which is one of the three decision support systems utilized in defense acquisition.By dividing the entire life cycle into several phases,an acquisition program goes through solution analysis,technical maturity,engineering and manufacturing development,production and deployment,operations and support,and retire processing phases,with the technological and manufacturing maturity improves simultaneously.By setting the milestone decision points between acquisition phases,the achievements of current phase and the goals of the subsequent phase can be evaluated.In this manner,the acquisition execution and phase transition can be supervised effectively and the program risk can be reduced significantly,which can finally realize the capability requirements described in joint capabilities integration and development system as an equipment.As a result,this work will focus on the defense acquisition system,to illustrate the acquisition phases and their corresponding tasks systematically,and finally provide a sufficient support for the related work.

Application of Artificial Intelligence on Situation Assessment and Game Countermeasure in Unmanned Battlefield

TANG Run-ze, ZHANG Cheng-long, LI Lin-lin

2020, 48(5): 25-31. doi:10.3969/j.issn.1009-086x.2020.05.004

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In the upcoming highly contested countermeasure battlefield,the unmanned combat ability,which enables the military unmanned cooperation,mutual cooperation,complementary advantage and effectiveness enhancement,is the key to win modern wars.The developments of current intelligent unmanned combat and potential techniques are analyzed in detail.The applications of artificial intelligence in situation assessment and game countermeasure are put forward.Finally,the future development and expectation of intelligent unmanned combat system are proposed.

Analysis on Technical Status and Developing Trends of Portable SAMs

QIAN Kun, GONG Min, CHEN Mei, LOU Shu-gen

2020, 48(5): 32-37. doi:10.3969/j.issn.1009-086x.2020.05.005

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Traditional low & extra-low altitude threats have been widened in recent local wars.Targets such as stealth fighters,unmanned aerial vehicles (UAVs),smart and guided weapons have emerged and technical features such as low-infrared,high-maneuverability,strong antijamming and clustering trends have been presented,which lead international military users to raise new requirements for portable surface-to-air missiles (SAMs) beyond their traditional combat performances and shoulder-firing mode.To make a deep research on new international market demands,systematically study on technique performances and transfer quantity of mainstream 3rd-generation portable SAMs,compare the technical status of available portable SAMs,analyze the system technical index and sub-system technical developing trends of new-generation portable SAMs,as well as research the key techniques and solutions.The result shows that new-generation portable SAMs should possesses features including low-infrared-target interception,high guidance accuracy,strong antijamming performance,multi-mission and multi-platform expansion capability.

Solution of State Variable for Hypersonic Vehicle Equilibrium Glide

MENG Fan-qing, TIAN Kang-sheng

2020, 48(5): 38-43. doi:10.3969/j.issn.1009-086x.2020.05.006

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The solutions of flight speed,path angle,longitudinal range,altitude for hypersonic glide vehicle under the condition of equilibrium glide are studied.The analytical expressions between flight speed,longitudinal range,altitude and flight path angle are obtained by theoretical derivation,and the numerical solution of flight path angle is obtained by fourth-order Runge-Kutta method.The approximate solution of flight path angle is obtained by using curve fitting theory.The simulation results show that there is a nonlinear relationship between flight path angle and flight time under the condition of equilibrium glide,and the analytical solutions of flight speed,longitudinal range and altitude can well characterize the numerical solution.

Research on Generation Style of UAV Cluster Intelligence

XU Rui-ming

2020, 48(5): 44-49. doi:10.3969/j.issn.1009-086x.2020.05.007

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Unmanned aerial vehicle (UAV) cluster operation is an important operation mode in the future.The research on the generation mode of UAV cluster intelligence and the way to realize it is the basic support for the determination of UAV cluster operational organization and operational design.Firstly,the centralized,bionic and function distributed generation model of UAV cluster intelligence is proposed,and the corresponding ways of realization are discussed in general.Secondly,the way to realize intelligent effect of task adjustment and route replanning in war is proposed, based on parallel system architecture.Finally,the way of route search,attack and optimization based on emergence of bionic behavior intelligence is proposed.

Research on Roles of the AWACS in Close Air Support

MA Ying

2020, 48(5): 50-58. doi:10.3969/j.issn.1009-086x.2020.05.008

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As the air core node of multi service and joint operations,the airborne warning and control system (AWACS) conduct important roles in close air support.In close air support operations,effectively form an integrated air-to-ground combat capability is an urgent problem to be solved.Combined with the typical combat operation processes and organizations of the close air support,proposes that the AWACS should strengthen the air target identification,the battlefield management,the communication relay and the ability to generate and share the situation.The study result may have certain traction and reference significance for the development of the AWACS and aerial information systems.

Modeling of Air Target Threat to Warship Based on Deep Reinforcement Learning

FANG Xiao, ZENG Bi, SONG Xiang-xiang, JIA Zheng-xuan

2020, 48(5): 59-66. doi:10.3969/j.issn.1009-086x.2020.05.009

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With the development of intelligent weapons,the traditional training methods could notmeet the demands of large-scale modern warfare.In the past decade,artificial intelligence (AI) methods such as deep reinforcement learning have made great breakthroughs in chess and electronic competitive games.It proves that the AI methods have great advantages in solving large searching space problems.Furthermore,the problems of situation prediction and temporary adjustment could be solved more effectively by AI methods.A new method for modeling of air target threat is proposed based on the research of deep reinforcement learning.The parallel scene modeling technology and the air target behavior modeling technology are used to construct the model of deep reinforcement learning.The convergence penetration strategy is calculated with iterative learning under the scene of single airplane.The successful attempt verifies that the practicability of deep reinforcement learning in modeling of air target threat.It provides support for the further research on the modeling of fleet joint air defense.

Survey of Small Targets Detection Technology in Optical Imaging

WANG Zhi-hu, SHEN Xiao-qing, GUI Wei-long

2020, 48(5): 67-73. doi:10.3969/j.issn.1009-086x.2020.05.010

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Small targets detection in optical imaging is a difficult problem in the field of computer vision.At the same time,with the expansion of imaging distance and the requirements of long range strikes and rapid attack/defense in modern warfare,there will be a lot of realistic needs for small targets detection.Therefore,how to quickly and accurately detect small targets in complex backgrounds is of great significance in areas such as intelligent control,visual navigation,and target monitoring.Reviews the research situation of infrared small targets detection,visible small targets detection and small targets detection based on deep learning in recent years at home and abroad,in order to seek new exploration and breakthrough,as well as provide useful reference for the development of small targets detection technology.

Theoretical Analysis of Antenna Polarization and Application in Radar Countermeasure

WU Chang-song, YU Wei-gang, LU Yong-wei, ZUO Guo-yin, XU Chang-wei

2020, 48(5): 74-78. doi:10.3969/j.issn.1009-086x.2020.05.011

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Polarization is the fundamental characteristic of electromagnetic wave as well as time domain and frequency domain.The use of the polarization information can effectively improve radar capabilities of antijamming,target detection and target recongnition.The polarization characteristics of radar antenna are discussed and used to solve some practical problems in radar countermeasures.Based on the decomposition theory of arbitrary polarization wave,the principle of linearly-and-circularly-polarized component method is analyzed.The relevant mathematical models are established.The efffects of axial ratio and polarization mismatch factor on radar receiver sensitivity and Jamming-to-Signal power Ratio at the receiving end are given.The study is of some value in the development of radar counter equipment and the evaluation of radar counter test.

Evaluation Method of Combat Support Unit Capability Based on Fuzzy Reasoning

LI Ya-xiong, MA Feng, WU Jian

2020, 48(5): 79-85. doi:10.3969/j.issn.1009-086x.2020.05.012

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Carrying out the capability evaluation and construction of combat support units is an important support for the formation of system capabilities under the informatization condition.Compared with the capability assessment at the level of combat support equipment,the implementation of capability assessment for sub-units will encounter many difficulties,such as more qualitative assessment indicators,strong fuzziness of evaluation criteria,etc.Fuzzy reasoning method has obvious advantages in solving the above problems.Through the steps of fuzzy set assignment,fuzzy modeling of input values, establishment of fuzzy reasoning rules,construction of synthetic fuzzy sets,and defuzzification processing,a fuzzy reasoning-based capability evaluation method for combat support units is established.The method can be easily understood by military personnel and has important military application value.

Research on Equipment Maintenance Support Mode in the New Period

WANG Lei, LIN Tao

2020, 48(5): 86-91. doi:10.3969/j.issn.1009-086x.2020.05.013

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Discussed how to solve the equipment maintenance and support work in peacetime and wartime after China’s military reform.Through the research on the equipment maintenance support mode based on performance-based (PBL),civil-military integration and equipment maintenance support mode at both peacetime and wartime,it put forward a more suitable logistic support mode for characteristics of the modern military system,which makes the army’s original maintenance support unit continue to play the role of tbackbone in the new military struggle.As an effective way to improve the efficiency of equipment maintenance support in industrial departments,it would promote the in-depth development of civil-military integration support.

Mission Reliability Growth Modeling and Evaluation Method for Military Aircraft During Flight Test Stage

GAO Ya-juan, MA Tao, WU Hong-jiao

2020, 48(5): 92-96. doi:10.3969/j.issn.1009-086x.2020.05.014

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Considering the reliability growth of fighter plane during flight test stage,a mission reliability evaluation method based on Gamma distribution is proposed.The suitability of Gamma distribution to reliability growth process during flight test stage is analyzed.The effectiveness of the proposed method has been demonstrated by flight test data of an aircraft.The result shows that the method can be applied to mission reliability evaluation of military aircraft during flight test.

Text Categorization Algorithm for Automatic Document Review

GUO Ze, JIAO Qian-qian

2020, 48(5): 97-104. doi:10.3969/j.issn.1009-086x.2020.05.015

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A machine learning based improved native Bayes algorithm proposed to solve the text classification problem in automatic document review field.Firstly,it improves naive Bayes algorithm and applies it as the classifier.Then a genetic algorithm is adopted to train all the feature weights.Finally,a table and figure position based identification algorithm is used to improve the results.The experimental results show that the algorithm performs better than traditional (K-nearest neighbors) KNN and naive Bayes in most cases,especially when the sample sets have more wrong samples.It can improve the accuracy of automatic document review effectively.

Design of a Multifunction Target and Jamming Simulator for Windband Radar

YU Wei-gang, WU Chang-song, ZHANG De-xin, ZUO Guo-yin

2020, 48(5): 105-112. doi:10.3969/j.issn.1009-086x.2020.05.016

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A design method of multifunction target and jamming signal simulator based on digital radio frequency memory (DRFM) technology is presented for wideband radar test verification,identification and evaluation.The design can simulate the echo signal with target model characteristics and motion characteristics.It can also product many kinds of radar jamming signals and noise signals,which can be usedto construct radar test electromagnetic signal environment,and provide reference for the wideband radar function and performance test.The design can effectively improve the radar test efficiency,realize the repeatability,ergodicity and accuracy of the test,ensure the standardization of radar test,effectively support the test verification and evaluation of radar equipment,and has good popularization and application value.

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