导航卫星中断频次的分析方法

面向导航卫星中断频次的定量分析需求,该文分析导航卫星中断产生的主要原因,给出中断频次分析的流程,并针对分析过程中的三个关键问题,研究提出具体实施方法,包括通过相关性分析快速定位底层中断事件,通过中断树建立指标分析模型,并融合在轨数据、地面试验数据快速预估得到底层功能异常率等。最后通过示例进一步说明中断频次分析过程。该文方法已应用于北斗导航卫星工程。     

Research on navigation of satellite constellation based on an asynchronous observation model using X-ray pulsar

Pulsar navigation is a promising navigation method for high-altitude orbit space tasks or deep space exploration. At present, an important reason for restricting the development of pulsar navigation is that navigation accuracy is not high due to the slow update of the measurements. In order to improve the accuracy of pulsar navigation, an asynchronous observation model which can improve the update rate of the measurements is proposed on the basis of satellite constellation which has a broad space for development because of its visibility and reliability. The simulation results show that the asynchronous observation model improves the positioning accuracy by 31.48% and velocity accuracy by 24.75% than that of the synchronous observation model. With the new Doppler effects compensation method in the asynchronous observation model proposed in this paper, the positioning accuracy is improved by 32.27%, and the velocity accuracy is improved by 34.07% than that of the traditional method. The simulation results show that without considering the clock error will result in a filtering divergence.     

弹道交班自适应算法研究

为实现复合制导不同制导弹道的平滑过渡,用二阶吻合法设计了一不同制导律间的指令交接导引段。建立了自适应弹道交接导引算法的模型。理论分析和仿真结果表明,该算法具较好的弹道过载平滑能力,有一定的应用价值。     

Ту-154М变稳飞机空中飞行模拟试验评述

依据Ту－１５４М变稳飞机的特点，主要进行了不同操纵器、不同控制律和不同显示画面的飞行试验研究。特别是通过中央杆和侧杆、电传系统不同控制律飞行品质特性之间、两种先进控制方案及不同显示方式的比较，不仅掌握了这方面的试飞技术和评定技术，还亲身体验到变稳飞机在发展仿真技术，新机预研及提高试飞员试飞技术和评定技术等方面的巨大作用。     

电子商务及其基本法律问题

本文简单阐述了电子商务的概念、模式、基本流程及其基本法律问题和目前的立法现状，弄清这些问题，无论是对于从事电子商务还是IT产业的经营、管理以及进行相关的科研开发，都具有十分重要的意义。     

Tunnel/predictor display with two-axis control coordination and simplification

A longitudinal-lateral control coordination and simplification concept is considered for a tunnel/predictor display, which presents the command flight path and a specified future aircraft position in a 3-dimensional format to the pilot, for improving flight path control. A basic element of the proposed concept is the generation of common longitudinal-lateral transfer characteristics of the predictor-aircraft system for the crossover frequency region. Control coordination is supported by a dynamics similarity between the longitudinal and the lateral response characteristics of the predictor position in closed-loop pilot control actions. The control coordination and simplification concept is considered to support the pilot in manual flight path control, directed at an enhancement of his control performance and at a reduction of his workload. Results from pilot-in-the-loop simulation experiments support the theoretical findings and show the effectiveness of the proposed predictor concept with control coordination.     

卫星交会的自主导航技术

论述卫星交会自主导航的飞行任务背景和概念 ,综述国内外学者正在进行探索研究的思路 ,以期引起国内学者的的注意、探讨和深入研究。     

卫星定位导航系统中各因素对D-R定位算法精度的影响

D- R定位算法在理论上可以用于定位。在实际工作中 ,用户的定位精度是进行定位时首先需要考虑的问题。文中主要讨论 D- R算法本身固有的定位误差。首先根据 D- R算法的定位公式推导出算法的精度误差因子。然后根据卫星定位导航系统的工作过程 ,确定了影响用户定位精度误差因子的因素并对这些因素对精度误差因子的影响进行了计算机仿真。仿真结果证明 D- R定位算法在一定条件下可以满足用户对定位精度的要求 ,用户精度误差因子可与现有的 GPS系统相当。     

鲁棒变结构制导规律研究

研究存在相对速度测量噪声时的鲁棒制导问题，根据一类变结构制导规律，分析了相对速度测量噪声、制导参数对导引收敛性的影响，以弹道收敛为准则，给出了实现鲁棒制导的条件，研究结果对设计先进的雷达制导系统具有重要意义。     

多重直扩信号的快速捕获

多重直扩信号的快速捕获得卫星定位及通信系统研制过程中遇到的一个主要课题，它的实现，不仅可以提高系统的多址能力，而且也是系统实现的必备条件，本文阐明了多重直扩信号的来源以及可被分离的理论依据，给出了多重直扩信号快速捕获的硬件实现方案及部分实验结果，得出了一些重要结论。