A new optimum method of shared aperture pattern synthesis is proposed based on the new global optimization algorithm, Wind Driven Optimization (WDO), for the shared aperture array antenna. Firstly, the space constraint condition of the array element adjacent to two arrays is designed, and the Peak Side Lobe Level (PSLL) of the two sub-array patterns is used as the objective function.Thenaccording to the constraint formula, the initial coordinates of sub-array 1 and sub-array 2 array elements are developed successively. These two sub-array elements positions are optimized by using the WDO method to reduce PSLL of the pattern synthesis, in order to fulfill the design of shared aperture antenna array working at different frequencies. Finally, a simulation is made and the result shows that: compared with the particle swarm optimization algorithm and the traditional SMI algorithm, this proposed algorithm has better feasibility and effectiveness in the shared aperture pattern synthesis.

In view of the problems of the loss of detailed information caused by wavelet transform, the non-sparsity of low-frequency subband coefficient decomposed by Non-Subsampled Contourlet Transform (NSCT), and the poor comprehensive performance of infrared and visible image fusion, an algorithm for fusion of infrared and visible images is proposed based on sparse representation, NSCT, and Pulse Coupled Neural Network (PCNN). Firstly, the original image is decomposed by NSCT to obtain the low-frequency and high-frequency subbands.Secondly, the K-SVD (Singular Value Decomposition) algorithm is used to carry out dictionary training on the low-frequency subband to realize the sparse representation of low-frequency subband and the fusion of low-frequency sparse coefficients. Then, the spatial frequency of the high-frequency subband is utilized to stimulate PCNN, and the coefficient with more ignition times is selected as the fusion coefficient of the high-frequency subband. Finally, the NSCT inverse transform is applied to the low and high frequency subband fusion coefficients to obtain the fused image.The experimental results show that the proposed algorithm has a great advantage in subjective visual effect and objective index evaluation, and its comprehensive performance is superior to that of the existing algorithm.

To solve the problem of passive locating of external emitter，a batched processing algorithm is proposed for the parallel execution of multi-target locating and trajectory processing based on Direction of Arrival (DOA) and Time Difference of Arrival (TDOA). First，initial locating states of the external emitter are evaluated according to the geometry theory. Then，the trajectories are initialized according to the valid locating value. After that，the Advanced Multiple Hypotheses Tracking (AMHT) algorithm is designed for the data association between measurement trace points and trajectories of targets.The Extended Kalman filter is deduced along with the measurements from DOA and TDOA (DT-EKF)，which is used for maintaining the trajectory.Simulation results show that the proposed algorithm can perform simultaneously locating and trajectory processing for multiple targets，and acquire higher locating performance than that of the traditional methods.

To effectively evaluate the effects of three kinds of active laser jamming modes of angle deception, high-repetition-frequency deception and high-repetition-frequency suppression, we made a ballistic simulation of the three jamming modes by taking a certain proportional guidance missile with over-gravity compensation as the research object. The main mathematical models were established, including the models of laser energy density, laser atmospheric transmittance, the view angle of seeker with proportion guidance, the seeker energy tracking, the seeker generating the proportional guidance law with over-gravity compensation, and missile control law, which constituted a closed-loop simulation system by using missile kinematic and dynamic equations. Then, the setting position and setting distance of jammer and the jamming laser energy were taken as simulation variables, and the full ballistic simulation of the three kinds of active laser jamming was completed.Simulation results show that: lateral setting of the jammer, the appropriate increasing of the setting distance and the increasing of the jamming energy can increase the miss distance and achieve a good jamming effect. The simulation system can provide a platform for the effect evaluation of electro-optical countermeasure and a reference for the tactical application of weapons.

Aiming at the existence detection problem of suppression interference, a suppression interference detection algorithm based on Fractional Fourier Transform (FRFT) domain peak characteristic is proposed for pulse-compression radar. First, from the perspective of complete radar anti-jamming system, the general idea of combining the existence detection of suppression interference with target detection and interference classification is put forward.Secondly, based on the analysis of the difference between the peak characteristics of the FRFT domain LFM signals and the suppression interference signals, the peak order of the echo signal in the FRFT domain is selected as the characteristic parameter. Then, the sequential decision algorithm is used to determine the peak order of the multi-stage echo signal in the FRFT domain, thus to complete the existence detection of suppression interference. Finally, the effectiveness of the proposed algorithm is verified by simulation experiments.

A new method is given for task allocation of multiple Unmanned Aerial Vehicles (UAVs). Firstly, the capability function of the UAV is established, and the methods for calculating the multi-UAV cooperative attacking position and the pitch angle of the UAV are given by using the Jacobian matrix of capability function.The UAV's damage cost index function, voyage cost index function and income value index function are established. The dynamic task allocation method for multi-UAV cooperative combat is presented. A simulation experiment has been conducted, and the result shows that: compared with the task allocation methods not considering the capability function, our method obtains greater target income value and can improve the multi-UAV cooperative attacking capability.

Aiming at the UAV flight control software with complicated functions and high real-time requirements，and taking the flight control computer with distributed architecture based on CAN bus as a platform，we designed the strategies for static and dynamic load balancing by utilizing software bus. In addition，the mechanism of function module migration between the nodes was designed. These methods could solve the problems caused by the load imbalance of nodes in the distributed flight control system，i.e.，declining of operating efficiency and wasting of resources，and guarantee the efficient and continuous operation of the system. Finally，experimental verification was made，and the result showed that:both types of load-balancing algorithms can schedule the functional modules accurately and guarantee the real-time performance，and thus the reliability and security of the distributed flight control system are improved.

To solve the problem that the magnetic field distribution of submarine at high altitude is difficult to measure in aeromagnetic anomaly detection, the Maxwell equation set and the boundary elements method are taken into consideration. According to the Green function and the distribution of vector potential, the spatial distribution of magnetic field of submarine is obtained in the prediction space, and the prediction model of submarine magnetic field is established. By using the magnetic dipole to simulate the submarine target, the prediction model is validated preliminarily in theory. Further more, an experiment is designed to verify the effectiveness of the prediction model.The results of the theoretical test and experimental verification show that the mean absolute error and the mean relative error of the submarine magnetic field prediction model using boundary elements method are respectively 0.220 5 nT and 2.368%.

To improve the precision of maneuvering target tracking under non-Guassian noise condition, a tracking algorithm based on Interactive Multi-Model ultimate iterative Unbiased Finite Impulse Response (IMM-ultimate iterative UFIR) filter is proposed. The algorithm takes the ultimate iterative UFIR, which has lower sensitivity to errors in the noise statistics, as its sub-filter to estimate the state of each model, and the state of maneuvering target is obtained by fusing the states of multiple models.Simulation results show that: under complex noise conditions, IMM-iterative UFIR has a higher precision than that of the Interactive Multiple Model Kalman Filter (IMM-KF), and less calculation cost than that of IMM-PF, which has a good balancing between the tracking precision and calculation amount.

To the problem of spaceborne multi-spectral image compression，a compression scheme based on sub-band spectral transform is proposed. First，two-dimensional discrete wavelet transform is performed to each band of multi-spectral image sequences for removing the spatial correlation.Subsequently，in order to remove the spectral correlation，each level of the sub-bands resulted from wavelet transform are regarded as a whole，and sub-band spectral KLT is performed on the two bands by using serial pairwise transform. Finally，Embedded Block Coding with Optimized Truncation(EBCOT)algorithm is performed on all principal components to realize optimal rate-distortion compression. Experimental results show that the proposed algorithm not only provides better compression performance，but also has lower encoding complexity，which is suitable for the onboard compression of multi-spectral images.

As the key link of Condition-Based Maintenance (CBM),condition assessment has an important influence on the subsequent CBM decision-making of equipment.In order to make the status assessment more accurate and reasonable, a method of equipment condition assessment based on cloud model and D-S evidence theory is put forward to overcome the strong subjectivity of existing evaluation methods.The first step is to use the cloud model to obtain the membership degree of the state index, and the second step is to modify the source of the evidence. Finally, the multiple evaluation indexes are fused by D-S evidence theory, and the evaluation results are obtained.The rationality of the new method is verified by the example analysis of radar seeker condition evaluation.

In target recognition, the sensor data is full of uncertainty.This paper proposes a sensor data fusion approach for target recognition based on weighted belief entropy in Dempster-Shafer evidence theory framework. Firstly, the uncertain information in the Frame of Discernment (FOD) is integrated into the Deng entropy model . Then, the weighted Deng entropy is applied to measure the uncertainty of the sensor data from different sources. Finally, the fusion of the conflicting data is implemented, based on which the decision-making on target recognition is realized. The rationality and effectiveness of the proposed method are validated by numerical simulations as well as the comparative experiments.

Aiming at the fast C/A code acquisition of GPS software receiver under weak signal conditions, a new fast acquisition algorithm with high sensitivity is proposed. Firstly, the autocorrelation loss and accumulative error of C/A codes are reduced respectively by using the average correlation technique and the carrier frequency error compensation technique. Then, the complexity of coherent cumulative operations is reduced by use of superposition correlation,and the time-consuming of frequency stepping search is decreased by cyclic shift.Experimental results show that the proposed algorithm can realize the acquisition of weak GPS signals, and has moderate computational complexity and high acquisition probability, which is suitable for the high-sensitivity software receiver.

To avoid boundedness and one-sidedness in the research on the development of USA's sixth-generation fighters，it is proposed based on methodology that we should do the research by integrating the three aspects together，i.e.，tracking and analyzing the development trend of USA's sixth-generation fighters and relative technologies，summarizing the US army's requirements on the sixth-generation fighters (Request for Information) and the corresponding response of the industrial communities，and concluding the development histories of each generation of fighters in the USA and focusing on current development of the sixth-generation fighters.Our viewpoint is demonstrated in the end.

Geomagnetic measurement error compensation technology is one of the key technologies in geomagnetic navigation，which is essentially a comprehensive issue of the calibration of magnetometer and the compensation of vehicle interferential magnetic field. The geomagnetic measurement error compensation and the research progress of its approaches are reviewed in this paper. The research status of this technology at home and abroad is illustrated，and the compensation models and compensation methods are analyzed. The key technologies and existing problems which restrain its development are pointed out,and its developing trend is proposed.

There is a certain amount of idle time in the Time Triggered Protocol (TTP) bus in practical applications of avionics interconnection.With the energy-saving “green avionics” concept penetrating into all aspects of the avionics system design, a message-scheduling table generation method is presented, in which energy efficiency is proposed as the optimization objective. On the premise of ensuring schedulability, the idle time resource is used to reduce the information symbol rate reasonably. By building a message allocation model of Static Packing (SP), the scheduling slack of the TDMA period of the TTP bus is optimized and allocated to each node to reduce the symbol rate of some of the packs, so as to save energy.A case of the message set is constructed in which messages belong to different nodes and have a variety of periods and length parameters.Case studies show that, compared with the conventional methods not using SP and frequency reduction optimization, this method can not only guarantee the schedulability of messagesbut also effectively reduce the energy consumption in transmission.

Signal-in-Space (SIS) accuracy is one of the basic performances of satellite navigation system.Considering the disadvantages of existing accuracy calculation models, we proposed a segmented SIS User Range Error (URE) evaluation model, carried out a study on the models for evaluation of SIS User Range Rate Error (URRE) and the User Range Acceleration Error (URAE), and used the broadcast ephemeris and precise ephemeris to evaluate the SIS accuracy of GPS and BDS. The results show that:the URE of BDS C02 and the URAE of GPS PRN10 are relatively larger, while the SIS URE, URRE and URAE of the other GPS and BDS satellites all conform to their own indicators.It verified the effectiveness of the proposed accuracy evaluation method.

In order to solve the problems of low locating precision and low recognition rate of the airport identification algorithm in sub-meter high-resolution remote sensing imagesa new identification algorithm based on Deep Convolutional Neural Network (DCNN) is proposed.Firstlythe bi-cubic interpolation algorithm is used to down-sample the original single-phase remote sensing images and convert them into grayscale imagesand the pre-processed images are obtained by fuzzy enhancement.Secondlythe edge information of the images is detected by using Canny edge detection operatorand the straight line segments are extracted by using probability Hough transform.The linear regions are preliminarily screened and merged by judging whether there are parallel lines.ThenDCNN is used for judging the merged regions to acquire the recognition probability of the corresponding regions.Finallythe airport area is obtained by analyzing the probability values of the candidate regions.Simulation experiments were made to the two kinds of remote sensing images with high resolutionthe recognition rate was 100% and the mean locating accuracy was 87.53%which proved the validity and versatility of the proposed algorithm.

Considering the construction demand of Beidou global navigation satellite system (BDS) in China, it is necessary to analyze the positioning performance of Beidou regional service satellite system (BD2), BDS and their combination with GPS, GLONASS and Galileo system.To BD2，the positioning performance of BD2, GPS/BD2 and GPS/BD2/GLONASS is analyzed by using two methods, simulation and factual observation data.Results show that BD2 completely meet the requirements of positioning performance in Beidou public service performance specification, and with the increase of the number of constellations，the positioning accuracy gradually improves, and the improvement of positioning performance in high-latitude regions is obvious when GLONASS is joined. To BDS, an analysis is made mainly by the method of simulation. The simulation results show that the positioning performance of the Asian-Pacific region still shows obvious improvement, and the mean value of PDOP in other regions reaches 1.2 to 1.6.In addition, the combination of the four major navigation systems will make obvious improvement on the positioning performance for polar regions.

In recent years, the tasks of airborne avionics system have been more and more diversified, a single display is unable to meet the mission requirements, and the integrated multi-display Cockpit Display System (CDS) has become a trend. In this case, it is particularly important whether the multiple monitors can respond to the operation correctly, and can display the information accurately. According to ARINC661 specification, a multi-display picture processing method based on the layer and session mechanism was implemented. We studied the operating mechanism of ARINC661 based CDS, confirmed the interaction mode between the User Application (UA) and CDS, explored the layer logic and the event processing mechanism of multi-display picture.A session mechanism between the layers and each display was established through UA, and finally the processing of the display picture was realized, through which the crew could obtain correct information of relevant tasks. The simulation result shows that the design is reasonable and the operation is reliable.

To overcome the shortcomings of the existing safety control system of a large Unmanned Aerial Vehicle (UAV), we designed a portable Beidou ground station and an airborne BD safety controller by using Beidou short-message communication technology, which realized the passive safety control of Beidou short-message instructions and the self-judgment based active safety control of the safety control region.An independent MCU board was used as emergency backup device when the laptop failed, which could send control instructions by pressing a button and improve the reliability of instruction transmission. The mode of multiple portable Beidou ground stations working at the same time could effectively increase the frequentness of short-message sending.It is proved by practical application that its operation is smooth and reliable.The results show that the design of the UAV safety control system is reasonable and feasible, which can be applied to other UAV safety control systems.

A-type locking device is widely used in airborne electronic equipment.The failure to fasten the equipment often occurs during operation，which may affect the mounting reliability of the electronic equipment. We studied the working process and mechanism of the A-type locking device through mechanical analysis and contact-surface analysis，and analyzed the factors that affect the fastening performance. The measures for design improvement were put forward，such as controlling the precision of pre-tension force，improving the angle of fixing and reducing the clearance.The result of simulations and tests showed that the improvement can effectively enhance the structural stiffness and strength of the airborne electronic equipment，and improve the mounting reliability of the equipment.

In order to implement the individual recognition of Phased Array Radar (PAR) emittersan analysis is made to the formation of the antenna pattern of PARand a PAR emitter recognition method is proposed based on the array antenna pattern.The method calculates the heading angle of the antenna array by using the data from two ESMsand obtains the function of the array factor.By comparing the received antenna pattern with the array factor functionthe antenna element pattern of the array is obtained.By matching the calculated element pattern with the element pattern in databasethe recognition of individual PAR emitter is implemented. The method extracts the inherent characteristics of the antenna pattern of the PAR to recognize the identity of the PAR emitter.The experiments demonstrate that the method is effective.

The selection of suitable matching area of geomagnetic map is important for ensuring the positioning accuracy of geomagnetic navigation.This paper puts forward a method for the automatic recognition and classification of the suitable and unsuitable matching areas of geomagnetic background field based on Principal Component Analysis (PCA) and GA-BP neural network.To select independent characteristic parameters containing the main componentsPCA is used to analyze the geomagnetic characteristic parameters.Thenthe GA-BP neural network model is constructedand the correspondence between the geomagnetic characteristic parameters and matching performance is establishedso as to realize the recognition and classification of suitable and unsuitable matching areas.Simulation results show that this method can efficiently find out a more effective matching areaand improve the positioning accuracy of geomagnetic navigation.