基于熵权的灰色关联概率数据关联算法

在多目标信息融合中,通过数据关联判断来自不同传感器的数据是否代表同一个目标,传统数据关联一般采用联合概率数据关联算法,单纯依靠状态量测且计算复杂。而基于灰色关联的概率数据关联算法,能够利用目标的多个特征信息进行数据关联,且计算简单准确。特征信息一般由专家主观判断给出。提出了基于熵权的灰色关联概率数据关联算法,由量测数据自适应的给出各特征的权重系数,不依赖于专家。仿真表明,该关联算法具有很好的工程实用性。     

火工展开机构负载模拟试验系统特性分析

文章介绍了某型号火工展开机构负载模拟试验系统的结构形式及工作原理,通过摆杆滑块机构与气体加载气缸直接联动,实现了加载的快速响应。文章对此机构进行了运动学分析和动力学分析,应用Matlab运算平台求解出机构运动的相关曲线以及加载力曲线,并对加载力试验结果进行了对比分析和理论分析。通过比较,两条曲线在两端的数据平均误差较小(小于5%),而曲线中间的平均数据误差较大(约为10%左右),实际试验加载曲线位置略高于理论设计曲线。     

遥测系统再认识

遥测系统是闭环系统,不是惯称的开环系统。与控制系统相比,遥测系统具有三大特点:测量信息源的不确定性;反馈通道与主通道的相关性;系统误差主要源于主通道。研究并获取系统传递函数是系统设计的重要内容,而机理分析和系统辨识正是适合该需求的有效措施。     

一种卫星数管中心计算机软件的工程实现

文章主要针对一种卫星数管中心计算机的软件需求,进行了操作系统和应用软件的设计和实现,并在数管分系统内部联试及与其它分系统接口匹配试验中对设计进行了验证。在软件的设计中,借鉴了空间数据系统咨询委员会的航天器星载接口业务(SOIS)和欧洲航天局的包应用标准(PUS),有助于软件的构件化和产品化。     

可变编码调制在遥感卫星中的应用效能研究

随着遥感卫星观测数据量的日益增加，卫星数据传输能力已成为制约遥感卫星使用效能的瓶颈因素。为充分利用近地遥感卫星数据传输的链路资源，采用可变编码调制（VCM）技术，通过对星地数传信道条件的动态评估，在保证链路传输误码率和链路余量的前提下，自适应地进行当前信道条件下的最优编码调制方式切换，充分利用系统链路余量，提高卫星星地数据传输效能。利用该方法，对VCM数传链路效能进行仿真分析，与相同符号速率的固定编码调制（CCM）体制相比，VCM传输效能平均提升42.1%，可为遥感卫星的数传通道设计提供借鉴。     

一种源源编译控制流优化方法

源源编译器是一种对源代码进行重构和分析的工具,在程序设计语言研究领域有着广泛的应用。给出了一种源源编译的控制流结构优化方法。方法结合编译结构分析,对于可化简合并的典型控制流结构,进行结构分析;经数据流分析满足优化条件后,实现基本块的合并。优化后程序的结构更加清晰,可读性更好。方法在SUIF编译器上实现,经使用Olden基准测试程序试验,有效提高了源代码的翻译质量。     

Radio/FADS/IMU integrated navigation for Mars entry

Supposing future orbiting and landing collaborative exploration mission as the potential project background, this paper addresses the issue of Mars entry integrated navigation using radio beacon, flush air data sensing system (FADS), and inertial measurement unit (IMU). The range and Doppler information sensed from an orbiting radio beacon, the dynamic pressure and heating data sensed from flush air data sensing system, and acceleration and attitude angular rate outputs from an inertial measurement unit are integrated in an unscented Kalman filter to perform state estimation and suppress the system and measurement noise. Computer simulations show that the proposed integrated navigation scheme can enhance the navigation accuracy, which enables precise entry guidance for the given Mars orbiting and landing collaborative exploration mission.     

On mid-term periodicities of high-latitude solar activity

The mid-term periodicities of polar faculae are studied separately for the total disk, northern and southern hemispheres of the Sun for a time interval from 1951 August to 1998 December. Apart from the 11-year Schwabe cycle which is the fundamental period and is found in all of the three time series, the following prominent results are found: (1) the rotational periodicity of solar activity at high latitudes is approximately from 28 to 32 days; (2) a large number of quasi-periods appearing in low-latitude solar activity (annual variation, 1.3–1.7 years, quasi-biennial oscillation, and 4–5 years) also exist in polar faculae; (3) the periodicities on both hemispheres are not identical.     

Track Association for Dynamic Target Tracking System Based on AP Algorithm

Track association of multi-target has been recognized as one of the key technologies in distributed multiple-sensor data fusion system,and its accuracy directly impacts on the performance of the whole tracking system.A multi-sensor data association is proposed based on aftinity propagation(AP)algorithm.The proposed method needs an initial similarity,a distance between any two points,as a parameter,therefore,the similarity matrix is calculated by track position,velocity and azimuth of track data.The approach can automatically obtain the optimal classification of uncertain target based on clustering validity index.Furthermore,the same kind of data are fused based on the variance of measured data and the fusion result can be taken as a new measured data of the target.Finally,the measured data are classified to a certain target based on the nearest neighbor ideas and its characteristics,then filtering and target tracking are conducted.The experimental results show that the proposed method can effectively achieve multi-sensor and multi-target track association.     

Determination of the solar rotation parameters via orthogonal polynomials

Accurate measurements of the solar differential rotation parameters are necessary for understanding the solar dynamo mechanism. We use the orthogonalization process to estimate these parameters. The advantage of the orthogonalization of the data in the tracer motion statistical analysis is outlined. The differential rotation is represented in terms of various types of polynomials. We compare the quality of a set of models of the solar differential rotation using the Akaike information criterion and choose the best one. Applying the proposed method, we studied the solar differential rotation and its North-South asymmetry using observations of coronal holes. A statistical analysis of observations from the Atmospheric Imaging Assembly (AIA) on Solar Dynamics Observatory (SDO) reveals the differential rotation pattern of coronal holes and its North-South asymmetry.