随着大规模低轨卫星星座的全面部署，对天基测控服务模式提出了新的挑战。分析了低轨卫星星座在常态运行、应急使用以及智能化应用中的测控需求；构建了新型天基测控服务系统，设计了前返向实时跟踪波束和全域静态波束组合应用的天基测控资源保障模式。提出了基于地面运管中心统一调度的天基测控服务模式，给出了即时计划驱动和“返向全时分发+前向业务驱动”两种典型模式下的系统工作流程，归纳总结了所述服务模式产生的效益。详细梳理了与所述服务模式相适配的卫星终端设计要求，明确了不同模式下的卫星终端工作状态。可用于指导后续对低轨卫星星座天基测控服务的工程化应用。

Multiple phases sectionalized modulation (MPSM) jamming is a kind of blanket jamming method against linear frequency modulation (LFM) radar, which can produce range-controllable noise-like jamming effect by dividing the signal into multiple subsections in the time domain and modulating different phases on each subsection. However, the partial relationship between the jamming effect and jamming parameters is complicated, which decrease the controllability of MPSM jamming effect. By transforming the problem of the controllability of MPSM jamming effect into the problem of the optimization of MPSM jamming effect, an optimization algorithm based on genetic algorithm (GA) is proposed to solve the problem in this paper. In the optimization based on GA, first, the objective function is constructed according to the jamming evaluation, the parameters are coded, the population is initialized, and the fitness value of the initial population is calculated. Then, the selection operation, crossover operation and mutation operation are performed, the next population is generated and its fitness value is calculated. Finally, judge if reach the termination, continue or output the optimization result and its corresponding parameters. The optimization method proposed in this paper can not only effectively increase the controllability of MPSM jamming effect, but also optimize the jamming effect. The simulation results show that the optimization method is feasible and has strong stability.

Due to the difficulty in deducing the corresponding relationship between results and parameter settings of multiple phases sectionalized modulation (MPSM) jamming, a problem occurs when obtaining the optimal local suppression jamming effect, which limits the practical application of MPSM jamming. The traditional method struggles to meet the requirements by setting fixed parameters or random parameters. Therefore, an optimization algorithm for MPSM jamming based on particle swarm optimization (PSO) is proposed in this study to produce the optimal local suppression jamming effect and determine its corresponding parameter settings. First, we analyzed the relationship between the degree of mismatch and local suppression jamming effect. Then, we set appropriate fitness function and fitness value. Finally, we used PSO to calculate parameter settings of a section situation and phase situation, which minimizes the fitness function and fitness value. The optimization algorithm avoids the tremendous computation of traversing all parameter settings, is stable, the results are repeatable, and the algorithm provides the optimal local suppression jamming effect under different conditions. The simulation experiments demonstrate the feasibility and effectiveness of the optimization algorithm.

For the disadvantage that piecewise random shift frequency jamming cannot generate deception to target speed,a jamming method based on phase sectionalized modulation is proposed for linear frequency modulation(LFM) pulse compression radars.Its basic principle is introduced,and the jamming signal's mathematical model is established.Then the magnitude-phase characteristics and pulse compression result of jamming signal are derived,and the impacts of number of signals,modulation phase and phase modulation value on overspread effect are analyzed.Simulation results show that the method can achieve reliable jamming effects and has higher jamming power utilization compared with piecewise random shift frequency jamming.

针对采用移频干扰对脉冲多普勒(PD)雷达实施干扰时容易被敌方识别的缺点,提出一种多相位分段调制干扰方法.对多相位分段调制的基本原理进行说明,建立数学模型推导干扰信号的表达式,以应用LFM信号的PD雷达为平台,对干扰信号的幅相特性和脉冲压缩结果进行推导,分析了信号分路数、调制相位数量以及相位调制值3个干扰参数对遮盖效果的影响.最后通过仿真对比验证说明,与移频干扰相比,该方法能够形成灵活可靠的多样化干扰效果.

To comprehensively and objectively describe the local coverage jamming of synthetic aperture radar (SAR),an evaluation method based on fuzzy synthesis is proposed.This paper analyzes the variables of local disturbance,brings forth the typical indexes of the assessment of the interference effect,and summarizes the evaluation process based on the fuzzy synthesis.Based on the principle of combination of qualitative analysis and quantitative analysis,the method of analytic hierarchy process (AHP) is used to determine the weight value of each evaluation index,and the membership degree of the combination of disturbance change factors is achieved through fuzzy comprehensive calculation.The simulation result of vehicle target local coverage interference assessment shows that this method can objectively describe the interference effect of multiple variables,and the evaluation result has a close corresponding relationship with the interference image.

在介绍跟踪雷达干扰技术研究现状的同时,对与之密不可分的跟踪雷达系统和干扰评估效果两个方面的研究现状进行了概述;从压制干扰和欺骗干扰两个方面,对当前典型的跟踪雷达干扰样式进行了介绍,分析,归纳和总结了跟踪雷达干扰技术状况和发展趋势;为进一步实现对跟踪雷达的有效干扰,跟踪雷达干扰技术必然向欺骗干扰,相干干扰,多点源角度欺骗以及复合干扰的方向发展.更多还原

The problem of ISAR image jamming is the main stream in radar countermeasures study. This paper proposes a new jamming technique for ISAR imaging based on Multiple Phase Sectionalized Modulation (MPSM) jamming method. Its basic principle and processing in intra-pulse and inter-pulse is analyzed in details. Then the final expression of MPSM jamming signal after ISAR imaging processing is derived, and the precise control method of jamming pattern by parameters design in double dimensions is provided. Simulation is conducted to prove the related jamming effects, and it is flexible and controllable to generate different jamming patterns and overspread effects by applying this new method.

For signal's design problem in partial coherent jamming,a new method based on multiple phase sectionalized modulation(MPSM) is proposed.The principle of MPSM is elaborated firstly,and the inter-pulse jamming signal generation is derived in details,where the multi-vector's superposition is obtained.Taking a typical coherent radar-PD radar as an example,the jamming effect after MPSM is analyzed in Doppler region,and the partial overspread effects are controlled by adjusting modulation parameters.Finally,the simulation is conducted to prove the related analysis above,and it is obvious that this jamming technique can produce plenty of false targets for partial confusion and will jam the speed information acquisition of real targets.

非均匀杂波背景会对目标检测的性能产生影响.首先给出了CFAR检测原理及其相参压制干扰方法,分析了两种条件下相参压制干扰的策略,重点讨论了干扰功率和干扰分布特性下的CFAR检测性能,并进行仿真验证.对干扰实施和效果评估具有参考意义.

Analysis of different kinds of jamming signal is one of key issues in studying SAR jamming technique. Firstly,three kinds of different jammings and their features are discussed respectively based on different coherence of the jamming signal;and then,power of the radar echo signal and jamming signal are analyzed to achieve expres-sion for corresponding jamming power and jamming -to -signal ratio on basis of radar equation by developing SAR signal processing model;finally,jamming power changing of three kinds of jamming in different coverage are ana-lyzed by simulation.The simulation result shows that certain advantage can be achieved by exerting partially coher-ent jamming on partial area of SAR image.

对雷达干扰信号的分析与设计是雷达对抗领域的热点问题之一.本文针对脉冲压缩体制雷达的特点,提出一种多相位分段调制干扰方法,通过部分破坏和保留原雷达信号的相干性实现局部遮盖干扰.对多相位分段调制的工作原理进行详细说明,给出干扰信号的数学推导.以应用线性调频信号的脉冲压缩雷达为例,结合自卫式干扰模型,推导了干扰信号的幅相特性和脉冲压缩结果,分析了调制参数对干扰遮盖范围的影响.最后,对相关结论进行仿真验证,说明应用该干扰方法能够产生灵活可控的局部遮盖干扰,具备实用性.

Based on the idea of the waveform agility in cognitive radars，the waveform libraries for maneuvering target tracking are discussed. LFM-waveform libraries are designed according to different combinations of chirp parameters and FrFT rotation angles. By applying the interact multiple model (IMM) algorithm in tracking maneuvering targets, transmitted waveform is called real time from the LFM-waveform libraries. The waveforms are selected from the library according to the criterion of maximum mutual information between the current state of knowledge of the model and the measurement. Simulation results show that waveform library containing certain amount LFM-waveforms can improve the performance of cognitive tracking radar.

Synthetic aperture radar is susceptible to electromagnetic interference by television networks ,communication networks and other wireless devices ,which seriously damages the image quality .Under the premise of the analysis of the characteristics of interference and signal model ,a method of SAR narrowband interference suppression based on com-pressed sensing was proposed .According to the difference of the FM slope of the SAR echo signal and the narrowband interference signals in the Chirplet dictionary ,interference signal was filtrated and suppressed in the reconstruction of the SAR echo signal ,and then use the conventional method to achieve the SAR image with the compressed data in which the disturbance is removed away .The simulation results show that the method not only can effectively suppresses narrow-band interference ,but also greatly reduces the amount of data in SAR imaging processing system ,which demonstrate the effectiveness of the proposed method .

The cross-eye jamming technique is a common method for monopulse tracking radar, which can cause a displacement towards the wrong direction and result in an angle deception. This paper proposes a modification of the traditional cross-eye jamming system, and the phase diversity processing of the received signal is introduced, and its precise expression of the offset is derived. The phase difference between the two branches of the signal processing is controllable, which is in the vicinity of 180 ° phase shift, reducing the coordination requirements of the two branches. Simulation with different parameters is conducted so as to prove the conclusion, and the flexible control of the jamming effort is realized by this new cross-eye jamming technique.

The design and analysis of radar jamming signal is a main stream in radar countermeasures' study. This paper proposes a method by using phase diversity processing, and the process of jamming signal's generation is elaborated in details. The frequency spectrum of the signal is derived after that, and the ambiguity function is used as a tool to analyze the characteristic of the jamming signal. Finally, the simulation is conducted to prove the conclusion above, and it is obvious that the jamming signal has great advantages in its nature.

When imaging maneuvering targets using Inverse Synthetic Aperture Laser Radar (ISAL), echo pulses disperse in range and the Doppler frequency varies with the slow time. The conventional Range-Doppler (RD) imaging algorithm is inapplicable of producing acceptable image. To solve these problems, an ISAL imaging algorithm for maneuvering targets is proposed. Firstly, the echo model of ISAL is established for a maneuvering target. Research reveals that, for a uniformly accelerated target, the ISAL signal after optical heterodyne processing can be approximated as a multi-component linear frequency modulation (MLFM) signal with a uniform chirp rate; when the Doppler frequency variation in azimuth can be estimated as a first-order polynomial, sub-echoes in each range cell are MLFM signals with different chirp rates related to the scatterers' azimuth coordinates. Subsequently, fractional Fourier transform (FrFT) is in use for eliminating the range dispersion's problem. A method combining FrFT and CLEAN technique (FrFT-CLEAN) are proposed after motion compensation for azimuth imaging. Simulation results demonstrate the validity of the proposed algorithm.

The integral-free Kalman filters which are widely used in target tracking are studied. The algorithms of Unscented Kalman filter (UKF), Cubature Kalman filter (CKF) and Square-root cubature Kalman filter (SCKF) are compared in details. A modified algorithm (MSCKF) is proposed to optimize the performance. When considering different original ranges and radial speeds, simulation of linear motion targets in Gauss noise is made and their tracking errors are analyzed. The result shows that different tracking filter algorithm has respective features in short time and long range signal processing. The MSCKF has better tracking performance in short time tracking application. It offers the guideline for application.

Cognitive radar is one of the main trend in radarˊs development. A method of building a LFM-waveform library is proposed on the basis of analyzing the feedback in cognitive tracking loop. By applying the interact multiple model ( IMM) algorithm in tracking maneuvering target, waveforms in the library are called timely so as to reduce tracking errors. Waveforms library is built by different combinations of chirp parameters and FrFT rotating angles, the waveform selecting rule is derived through the principle of mini-mum modelˊs uncertainty, and different selection strategies are obtained. Through analyzing the precision of tracking,the conclusion is drawn that the library of certain amount LFM-waveforms can improve the property of cognitive tracking radar.