How to upgrade the capability of submarine for countering with anti-submarine patrol aircrafts is always a serious issue for submarine forces.Based on the analysis made to composition of anti-submarine system,the anti-submarine steps of anti-submarine patrol aircraft and its method for collecting submarine information,the research status at home and abroad on underwater submarine detecting anti-submarine aircraft are summarized.The modes and methods of submarine confronting anti-submarine patrol aircraft,together with the actuality and development of submarine-launched antiaircraft missile,are expatiated.The study can be taken as a reference for military training and relative study.

Considering the complex environment for Airborne Warning and Control System (AWACS) and the information redundancy problem caused by different types of sensors,the state of research on architecture of multi-sensor management system is discussed.The basis for architecture design of the management system is analyzed based on the key technologies of sensor management and the relation between the sensor management system and other systems.Then,a new architecture is proposed,which provides a theoretical guidance for AWACS sensor management system formation.

Infrared/passive millimeter wave (IR/PMMW) combined guidance is currently the hot trend in the field of multi-mode combined guidance technology.The penetrability of infrared detection system under low visibility conditions is not as good as that of passive millimeter wave,while the passive millimeter wave detection image is not as good as infrared image in resolution.In order to better identify the target,a new method was proposed.Firstly,IR/PMMW image was de-noised by using the de-noising method of combing multi-wavelet packet with neighborhood average,and then multiple similar IR/PMMW images were obtained by using the multi-wavelet packet method,which were then fused with principal component analysis,and accurate histogram specification was conducted.Finally,according to the particularity of PMMW image,a region based image quality evaluation method was proposed.The experimental simulation results indicate that after processing with the new method,the definition of image is improved,and its easier to identify the target information.

Image of the outdoor scene is usually degraded due to poor weather conditions,thus forming a hazy image.So far,most single image dehazing algorithms ignore the effect of noise.Therefore,in consideration of the noise pollution,a new dehazing model is established,and a three-stage dehazing algorithm is proposed.In the first stage,the degraded image is preprocessed,to eliminate the interference of noise with image.In the second stage,a Median Dark Channel Prior (MDCP) algorithm is used for restoring the preprocessed image in spatial domain,enhancing the global contrast of the image.In the third stage,the local contrast of the image is enhanced in transform domain,for further restoring the details of image.Compared with those methods using the spatial domain only or without taking into consideration of the noise effect,the proposed algorithm can significantly improve the image quality and definition.

In order to solve the beacon point detection and matching problem in unmanned aerial vehicle (UAV) probe and drogue refueling,a near-infrared beacon detection system was designed,and a robust beacon point matching algorithm was proposed.The near-infrared beacon detection system was constituted with eight 850 nm wavelength near-infrared Light-Emitting Diode (LED) lights arranged uniformly in outer ring of the refueling drogue,and 850 nm band-pass filter integrated with Logitech C310 camera.To solve the mismatch problem caused by interference points,a beacon point matching algorithm based on geometric feature constraint was presented,which can accomplish the far interference point exclusion,feature point sorting,near interference point exclusion and feature point marking.The algorithm performance was validated through experiments in various complex environments.The results show that the beacon detection system has the advantages of high detection accuracy and reliability,and the beacon point matching algorithm can realize exact matching of beacon points robustly in various complex environments.Experimental results of relative position calculation show that the calculation is of high accuracy.

The initial heading angle of missile and the estimate accuracy of time-to-go considerably influence the missiles guidance performance.Based on angle-of-fall control optimal guidance law of air-to-surface missile,some in-depth research work was carried out.For a specified angle-of-fall,how to select initial heading angle to avoid command saturation was studied.The launch envelope of initial heading angle and terminal impact angle were given.In addition,since the optimal guidance law with angle constraint often achieves a curving ballistic trajectory,the traditional estimate method of time-to-go may bring about large error.Two new methods are proposed in this paper,which can overcome the shortcomings of traditional methods.Simulation results demonstrate the effectiveness of the proposed methods.

To solve the problem of quantitative evaluation of sky-wave radar anti-jamming capability under active deception jamming conditions,an intercepting probability model was established based on the characteristics of sky-wave radar and necessary conditions for intercepting radar signal.The effective probability of sky-wave radar anti-deception jamming measures was estimated by using the grey measurement method,and models were given for calculating the sorting and identification probability,the probability of simulating radar signals and the probability that interference-to-noise ratio met the requirement.On which basis,a model for evaluating the sky-wave radar anti-deception jamming probability was established.The anti-deception jamming capability of Azalea sky-wave radar system was evaluated under typical conditions by use of this evaluation model,thus confirming its feasibility and validity.

The attitude algorithm of strapdown inertial navigation system (SINS) is a key part of its navigation algorithm.Describing the change of carriers attitude with quaternion has found a wide application in practical engineering,of which,the accuracy of initial quaternion extraction has a direct influence on the calculation accuracy of navigation.To this problem,on the basis of traditional extraction algorithms,an initial quaternion extraction algorithm based on K-matrix was obtained,and a comparative analysis of quaternion extraction with orthogonal and non-orthogonal initial attitude matrix was made.The extraction and verification of initial attitude matrix example showed that the extraction algorithm based on K-matrix has a lower computational complexity,and it can effectively improve the accuracy of quaternion extraction for non-orthogonal attitude matrix.The method provides a reference for improving initial quaternion extraction algorithm of attitude calculation.

To reconnoiter targets in a large-scale area independently with onboard reconnaissance equipment was one of the most important applications for UAVs in modern battle field.Focusing on the problem of effectiveness evaluation for UAV when executing reconnaissance tasks,a model was built up for CCD camera,and the advantages and the disadvantages of UAVs in excuting reconnaissance were analyzed.Based on which a model was proposed for evaluating large-range reconnaissance route planning.Then,using this model,the searching pattern of UAV,box-spiral,was improved and the path was analyzed.The improved pattern was verified by a simulation.The effectiveness evaluation model and the improved searching pattern can be taken as a reference for UAVs in taking reconnaissance tasks,which has certain engineering values.

In order to detect small moving targets effectively from the low SNR infrared image sequence under the interference of cloud background and noise,morphology Tophat filter was used to enhance the target by filtering out the low frequency background.Then,the Gaussian mixture background model was used for background estimation and adaptive background updating,to separate the foreground part from the background.Experimental results showed that:The Tophat filtering used together with Gaussian mixture background model can detect infrared targets accurately from the dynamic cloud background.

Considering the effect of vibration on imaging quality of photoelectric system,we established a simulated photoelectric imaging test system based on a 6-FOM vibration isolation system and the image capturing system.Image sequences under different vibration environments were collected through the vibration table tests,and the influence of such vibration parameters as amplitude and frequency on imaging quality were analyzed by calculating the sharpness of the images.Results obtained were studied and discussed in detail,which showed that:1) Compared with the frequency,the amplitude was even more influential on imaging quality of the photoelectric system; and 2) The effect of the high-frequency vibration was greater than that of the low-frequency vibration under the condition of equal vibration amplitude of different frequencies.The results of the study is useful for the research on the mechanism of influence of vibration to imaging quality of photoelectric system,and can be taken as a reference for the design of vibration isolation and the rational choice of shock absorber.

Analysis is made to the working principle and constitute of airborne electro-optical warning system,and some new airborne electro-optical warning systems in foreign countries and the development are introduced.The development trend and key techniques of airborne electro-optical warning system are also presented.

Since the square root Cubature Kalman Filter is not robust and unable to give a quick response during target online maneuvering,an algorithm of adaptive Cubature Kalman Filter (CKF) is proposed,which uses the square root form of CKF for iteration,that is,SCKF.This algorithm introduces a strong tracking filtering algorithm into SCKF,and introduces a fading factor for detecting and restraining the filtering divergence,which effectively overcomes the problem that a standard filter cannot quickly and accurately track the spatial target during its maneuvering,and improves the numerical stability of spatial target location and tracking.Simulation result shows that: Compared with standard SCKF,the adaptive SCKF can effectively improve the robustness of maneuvering target passive locating and tracking,has higher filtering accuracy and stability,and good real-time performance,which can better accomplish the tracking task of spatial maneuvering target.

Considering that it is impossible to implement complete observation to the states of the 3-DOF airborne electro-optical(EO) tracking and pointing platform,we made structural decomposition on the basis of the systems observability.An H∞filter was designed for the observable states of the system.And the designed H∞filter was studied through simulation combined with state feedback H∞stabilization control.The simulation results showed that:When there is uncertainty condition in the noise statistical properties,the H∞filter can observe the system states effectively and achieve better filtering effect with certain robustness.

Sea-scattered echo is the main interference for laser detection system in low-altitude sea-skimming target detection.Based on Pierson-Moscowitz sea wave spectrum,a geometric model of rough sea surface at different wind speeds is established,which is used as the height field of sea surface.By dividing sea surface into facets,and based on Cox-Munk statistical model on sea wave slope,the reflected echo of facet is calculated out,and a light scattering model of rough sea surface is established.By use of the model,a simulating calculation of the scattering light distribution of cone-field incident laser beam and the receiving power of detector is made.The results show that the scattering light distribution of rough sea surface is related with the incident angle and wind speed.For incident laser beam with cone-field,the scattering light is mainly distributed around the stereoscopic space in the mirror-image direction of incident beam.The smaller the wind speed,the more concentrated the distribution of scattering light; the greater the wind speed,the more dispersed the distribution.It provides an important theoretical basis for analysis of laser beam scattering properties and calculation of scattered echo from rough sea surface.

With the interline transfer area-array CCD KAI-01050 as the image sensor,a dynamic target imaging system based on a reflector splicing structure was designed.The CCD timing control and driving circuits were designed,and the related noise in video signal was eliminated by correlated double sampling(CDS).By analyzing the reason for image degradation in the central FOV of reflector splicing,a mathematics model for image restoration was established,to restore the image in the central FOV of reflector splicing.With FPGA as the core control device,the whole system adopted a ping-pong buffer structure for high-speed parallel processing of the image data.The system delay satisfies the requirement of dynamic target imaging.After restoration,the SNR for image in the central FOV is improved by 14.8 dB.

In order to enhance the safety of FlexRay protocol applied in avionic network in aircraft complied with CCAR23,a heartbeat message structure is defined and a membership protocol algorithm is designed and implemented for FlexRay protocol based on its transmission characteristics.The algorithm consists three phases:status announcement in static segment, negotiation in dynamic segment and decision-making in network idle time.It uses processes hosted by the node as management target and enable the reintegration of a process.Within one cycle,it can identify n faults in a 2n+1 processes member group while at least n+1 process are without fault.Test result shows that the algorithm satisfies the validity,agreement and self-diagnosis requirements of membership protocol.

To accomplish dynamic configuration and code updating of application programs on signal processing module in integrated modular avionics system,and based on current two-level bootloading process,a multi-level bootloading technology for DSP is employed to dynamically configure processing unit on systems commands to store and perform dozens of digital signal processing programs.Currently,the technology has been widely used in a series of avionic electronics equipments and supports stable and reliable dynamic configuration and code updating of application programs.

To improve the level of civil aviation security,the airspace capacity,operation efficiency and service ability,we put forward an optimal method for base station embattling based on Adaptive Genetic Algorithm(AGA).The significance,principles and evaluation index of Automatic Dependent Surveillance-Broadcast (ADS-B) base station networking are summarized.The ADS-B antenna radiation characteristics are studied through simulation,and the safety interval between base stations is calculated out.Then a mathematical optimization model for selecting base station site is built up and the solution procedures and steps of AGA are given.By using real-number coding and optimal preservation strategy,the optimal embattling of ADS-B base station is achieved.Experimental results show that the method,which is better than the basic GA,can effectively guide the optimization,improve the efficiency of network optimization and provide a reference for the later period of the base station networking.

In view of the problems that the state estimation of nonlinear error model has the shortcomings of long convergence time,low estimation accuracy,and large calculation cost,a twice rapid transfer alignment algorithm based on dual-model switching is presented.The commonly-used linear error model based on Euler angles and nonlinear error model based on quaternion were utilized. In the first phase,the nonlinear error model and extended Kalman filter were used.Then,when the attitude misalignment angle converges to a certain degree,the linear error model based on Euler angles and the conventional Kalman filter were adopted in the second alignment to get higher accuracy.The simulation and vehicle test results demonstrate that this method is feasible and can meet the requirements to accuracy and rapidity.

A simple but effective method was proposed for synchronization of a class of chaotic systems by use of uncertainness observer.The method needed no information about the external perturbation,and the design method of the observer was simple,which made it easy for engineering application.Numerical simulation was made to Lorenz chaotic system,which verified the fine performance of the method in chaotic synchronization.

A fault identification scheme based on integrated wavelet neural networks was proposed to deal with the fault identification problem of the satellite power systems.Firstly,the critical data of the satellite power system was utilized to identify a certain class of failure group preliminarily.Secondly,characteristics of this type of fault group were studied,and corresponding wavelet neural network was constructed for the further fault identification.Finally,simulation for a class of satellite power system was conducted,and the result verified the effectiveness of the proposed method.

For the problem that an optimal scheme for step-down-stress accelerated degradation test is difficult to or cannot be obtained through analytical methods,an optimization algorithm of Monte-Carlo simulation step-down-stress accelerated degradation test (SDSADT) based on Particle Swarm Optimization (PSO) is presented.This algorithm generates test degradation data through a number of repeated simulation tests,and finds the optimal monitoring frequency,detection times and sample size.With the minimum logarithmic asymptotic variance estimation of 100pth percentile of the lifetime distribution of the product at use condition as the objective,a statistical analysis of the degradation test data is made by using Maximum Likelihood Estimation (MLE) theory based on PSO,and a model of optimization design for simulation based SDSADT is established. Based on an example,the optimal design scheme is given under different constraint conditions,with the conclusion that this method is also applicable to optimization design for SDSADT of small-subsample product,and the final optimal test scheme is obtained.

Currently,the measurement of infrared signatures for U.S.military aircraft is implemented mainly by using airborne infrared pod systems.This paper presents a brief introduction to the U.S.airborne IR measurement systems and their test aircrafts in service,with emphasis on the summary and description of the airborne IR measurement systems at the Eglin AF base and the Navy Air War Center(NAWC).