卫星全球普查任务规划系统预处理模块的开发

全球普查任务利用地球观测卫星季节性地动态监测地球表面变化，是遥感技术在全球变化监测中一种应用。卫星全球普查任务规划系统为全球普查任务的实施提供了技术和工具支持。该文介绍了卫星全球普查任务规划系统中预处理模块的设计和实现，分析了预处理模块的结构和功能，重点讨论了全球表面场景划分的可视化、时间窗口计算和分析、卫星日常图像采集活动中候选场景的确定和场景拍摄优先级的动态调整的关键技术。     

基于协商对策的卫星任务规划冲突消解

主要对卫星任务规划过程中预处理阶段的目标冲突进行研究.为了更合理地确定卫星应用任务的时间窗口及个时间窗口的属性值,更有效地利用昂贵的卫星资源,首先对卫星任务规划预处理阶段的目标冲突进行了分析,给出了冲突的数学描述,针对冲突的特点提出了基于协商对策的冲突消解方法及协商流程,最后通过实例分析验证了方法在卫星任务规划中对目标冲突消解的有效性.     

卫星时间窗口计算的动态步长快速算法

针对卫星轨道连续跟踪采样的时间窗口传统计算方法计算量大、效率低的问题,提出了一种新的快速算法。为减少参与计算的采样点数量,算法通过预测参与计算对象之间距离动态调整采样步长;为使算法适于解决各类时间窗口计算问题,提出广义可视概念进行时间窗口判定。分别研究了卫星与地面点目标可见时间窗口、星间可见时间窗口、卫星对地面目标覆盖时间窗口、地面大范围区域卫星过境时间窗口的广义可视判断方法和预测距离计算模型。实验结果表明,算法与传统算法精度完全一致,效率提升约99.7%。     

基于改进遗传算法的多天线地面站硬件资源分配方法

多天线卫星地面站硬件设备资源分配问题是一个基于约束满足的复杂资源组合优化问题。在考虑任务执行时间、地面站可见时间窗口、地面站设备接收能力和设备链路约束的情况下,对多天线地面站硬件资源分配问题建立了高可用模型。以加权任务执行总时间为目标,以经典遗传算法为基础,根据问题特点改进了相关遗传算子,在进行遗传变异的过程中,通过深度优先搜索算法确定单个染色体对应的最佳资源分配方案,同时利用启发式信息优化搜索过程。最后通过高可用算例仿真表明,所建模型和算法是合理有效的。     

卫星对区域目标的时间窗口快速计算方法

为了提高卫星对区域目标时间窗口的计算效率,并兼顾结果的精确性,提出一种基于迭代修正的时间窗口计算方法.利用问题特性将卫星对区域的时间窗口计算化为对区域每条边界的时间窗口计算,首先在不考虑地球自转下得到每条边界的时间窗口,然后根据地球自转特征对计算结果进行迭代修正,最后对所有的边界的时间窗口进行综合得到区域目标时间窗口.该算法充分利用卫星轨道的基本特性,实现了对区域目标时间窗口的快速和精确计算.数值计算结果表明,改进算法计算效率高,计算结果精确.     

卫星全球普查任务调度系统的设计与实现

卫星全球普查任务是指利用星载遥感设备,周期性地对全球表面进行覆盖监测和数据采集。论文针对卫星全球普查任务需求的特点和卫星资源能力,建立了卫星全球普查任务调度系统。卫星全球普查任务调度系统主要包括想定管理模块、资源管理模块、场景管理模块、调度模块与仿真评估模块等功能模块,文中重点分析了系统核心的场景管理模块、调度模块与仿真评估模块的实现。     

面向存储资源优化的遥感卫星任务规划算法

针对遥感卫星的成像任务规划问题,按照任务重要性的不同,提出了两阶段调度策略,并设计了两个时间窗口选择规则。以星上存储资源优化为目标,利用地面站的下传活动将整个规划过程分为较小的调度区间,提出了可用存储空间上界估计算法计算每个调度区间的可调度存储资源容量,以此为基础对问题进行了简化,并给出了基于规则的启发式求解算法。实验结果表明,该算法是有效的。     

面向深空探测任务的实数遗传编码多星任务规划算法

针对面向深空探测任务的多星任务规划问题,综合考虑卫星对目标时间窗口、卫星姿态机动以及工作能耗等约束条件,建立了面向深空探测任务的多星任务规划问题模型,针对常规01编码在进行大规模卫星任务规划时,存在的编码长度过长等问题,提出了一种基于实数编码方式的遗传算法,以求解面向深空探测的多星任务规划问题.该算法采用了一种以目标为染色体的实数编码方式,相比传统的以时间窗口为染色体的01编码方式,缩短了染色体长度,可有效提高算法的求解效率.通过仿真算例分析,验证了基于实数编码的遗传算法对求解多星任务规划问题的正确性、合理性和有效性,并将其与基于传统01编码方式的遗传算法进行对比分析,其结果表明基于实数编码方式的遗传算法在寻优能力和计算速度上具有明显优势,这为求解面向深空探测任务的多星任务规划问题提供了一种新的思路和方法.     

基于蚁群算法的卫星地面站任务规划方法

卫星在运行过程中,与地面站之间存在许多可见窗口,只有在可见窗口之内,地面站才能直接对卫星进行观测和操作,因此,如何合理调度地面站资源,实现最大化利用星地可见窗口是一个重要的课题。本文定义卫星与地面站之间的可见窗口为任务集合,将蚁群算法应用于构造有效的任务调度序列,求解任务最大执行时间,即可利用的可见窗口时间最长。实验数据显示,蚁群算法有着优良的调度结果,同时其调度结果亦优于FCFS和贪婪算法。由此可以看出,该算法能有效求解卫星地面站任务调度问题。     

卫星任务调度系统的设计与实现

论文给出了一个卫星任务调度系统的总体结构及其功能,讨论了该系统实现过程中的任务描述、调度引擎、卫星时间窗口的仿真计算、调度结果的可视化展现等关键技术,归纳了系统的特点,并总结了今后系统的研究方向。     

卫星通信高速数据传输系统设计

设计一种用于卫星通信的高速数据传输系统。该系统采用Virtex-5系列现场可编程门阵列,由PCI Express通信模块和基于Aurora协议的光纤通信模块组成,具有双单工同时收发的特点。测试结果表明,该系统的PCI Express通信模块可实现8路通道工作模式,光纤通信模块的数据传输速率达到1.25 Gb/s,能有效模拟星载数据的下发和地面站对卫星的遥控。     

Multi-module satellite component assignment and layout optimization

In previous optimization methods for multi-module satellite equipment (component) layout optimization problem, each component was limited to certain module or supporting surface and could only search its position there. Components could not migrate from one module or supporting surface to another. In this case, the layout design of components within satellite module was seriously hindered from further improvement. In this study a component assignment and layout integration optimization algorithm is presented to deal with this problem, which can assign components to each module of satellite dynamically during optimization procedure. The aim of this paper is to expand the solution space of component layout optimization so as to further improve the component layout design. The proposed component assignment and layout integration optimization algorithm is inspired from the idea of stepwise regression in multiple regression analysis, which allows independent variables to enter or leave regression equation freely. In the proposed algorithm components enter the satellite module one by one in descending order of the product of mass and height. For all supporting surfaces within satellite module, each component will try all of them through layout optimization together with these components have been in the satellite module, and finally select the one with the best fitness as its initial assignment. At the same time, these components have been in the satellite module will be evaluated by their moment of inertia to decide whether they leave the current supporting surfaces and move to another or not. The layout optimization algorithm uses the differential evolution (DE) and random mutation operation to optimize the coordinates and orientations of components, respectively. The performance of the proposed algorithm is finally evaluated on a simplified satellite case. Experimental results show the proposed algorithm outperforms other two algorithms that did not consider component assignment in computational accuracy.     

Layout optimization of satellite module using soft computing techniques

This paper presents a hybrid method using soft computing techniques to deal with layout design problem of a satellite module. This problem is a three-dimensional layout optimization problem with behavioral constraints, and is difficult to solve in polynomial time. In this study, we firstly used a Hopfield neural network (HNN) to allocate the given apparatuses and equipment to the bearing plate surfaces in the satellite module. Then, we integrated genetic algorithm/particle swarm optimization (GA/PSO) and quasi-principal component analysis (QPCA) to deal with the further detailed layout optimization. The numerical experimental results showed the feasibility and efficiency of our method for layout optimization of a satellite module.     

#br# 基于多维数据模型的卫星质量评价模块组织方法研究

卫星质量评价模块的组织结构影响到用户能否有效地查找遥感产品信息,是挖掘和利用卫星数据资源的关键。针对现有卫星质量评价模块组织结构单一,检索效率低下问题,设计基于“星型”模式的在轨卫星质量评价模块信息多维数据模型,有利于多角度地展示卫星质量评价模块的动态信息,提高检索速度。将该模型应用于在轨自主卫星综合质量评价(ZGZHLPJ)系统组织结构的设计中,结果表明,系统组织结构更加有序和立体,用户使用更加方便快捷,验证了该模型的实用性。     

An evolutionary search procedure for optimizing time–cost performance of projects under multiple renewable resource constraints

This paper presents an effective procedure for optimizing time–cost performance of multi-mode resource constrained project scheduling problems in which activities are subject to finish-start precedence constraints under renewable limited resources. Associated with each execution mode of activities, there exists a direct cost, a processing time, and a set of required renewable resources. In optimizing time–cost performance, the procedure treats the cost as a non-renewable resource whose limit can affect the duration of the project and balances cost versus time through the notion of priority-rank. This is performed by the use of a module which handles multimode projects, and since the procedure has to call this module with different limits on the cost, the effectiveness of this module plays a key role in the overall efficiency. For this reason, an effective evolutionary search technique has been developed to create the basis of this module. For testing its effectiveness, this module has been tested on 552 largest multimode benchmark instances of the PSPLIB and the results are promising: For over 98% of instances, the module finds the best available solutions in the literature. The module also produces a solution for one of these benchmark instances that is better than all of the current solutions in the literature.     

基于北斗卫星的BGAN应急指挥监控系统设计

当前应急指挥系统平均响应时间过长,抗噪能力差。为解决上述问题,基于北斗卫星研究了一种新的BGAN应急指挥监控系统,针对系统的硬件和软件进行设计,系统硬件设计了采集模块、处理模块、通讯模块、指挥监控模块四部分,采集模块使用的采集芯片型号为AHD80H-9721,处理模块中加入了GDS110BB芯片,通讯模块选用型号为EXS2511芯片。在C/S结构上实现了通信报告功能和指挥服务功能。与传统应急指挥监控系统进行实验对比,结果表明,基于北斗卫星的BGAN应急指挥监控系统能够快速完成响应,指挥能力强,适用范围广,在噪声干扰状态下也可以稳定地运行     

A grid-density based technique for finding clusters in satellite image

High resolution and high dimensional satellite images cause problems for clustering methods due to clusters of different sizes, shapes and densities as they contain huge amount of data. Due to this reason, most algorithms for clustering satellite data sacrifice the correctness of their results for fast processing time. The processing time may be greatly influenced by the use of grids. In this paper, we propose a grid density based clustering method for detecting the clusters present in satellite images. The clustering is based on both the band values as well as the texture features in the satellite images. Experimental results are presented to establish the efficiency of this technique in detecting the clusters present in satellite images.     

GPS P码接收机本地信号发生器的FPGA实现

P码作为GPS军用伪码,具有结构复杂、周期长且码速率快的特点,这使得使用P码的软件接收机不仅定位精度高,且具有很强的抗干扰和反欺骗能力。能够实现任意卫星的任意时刻P码的产生,对于实现P码直接捕获和跟踪有很重要的意义。对于P码的产生原理和结构进行了分析,基于MATLAB设计了相应的P码发生算法并进行简单的算法仿真。之后针对FPGA硬件平台对P码发生器进行了相应的模块设计,包含寄存器模块、延时模块、周期控制模块和寄存器相位模块等。测试实验结果表明P码发生器可以基本无延迟地生成任意卫星、任意时刻的P码。