面向无人机的逐点偏移式卫星导航欺骗干扰方法

针对无人机在失控肇事、干扰航管、窥视窃密、恐怖袭击等方面的危害,本文提出一种基于逐点拉偏式卫星导航欺骗方法,通过重构错误的导航坐标系诱骗目标无人机飞离敏感区域保护地面安全。该方法将整个无人机欺骗过程看作是单步位置欺骗拉偏的时间迭代过程,首先根据无人机的运动学模型以及外部量测信息估算出无人机的真实位置点以及真实控制输入量;然后考虑无人机飞行控制器对欺骗效果的影响,在真实控制输入量中抵消掉预先设置的欺骗控制力矩效果,设计构造虚假卫星信号使得GNSS/INS组合导航模式下的滤波估计无人机位置点仍靠近原始期望目标点,但发生了偏差;最后这种偏差产生的无人机轨迹跟踪控制输入量会导致无人机真实状态点往欺骗目标点偏移,实现单步卫星导航欺骗效果。单步欺骗过程在时间上的迭代运用,可实现无人机位置的逐点偏移式欺骗。仿真结果显示利用逐点偏移式卫星导航欺骗方法能使得目标无人机慢慢偏离原始轨迹而跟踪欺骗轨迹,且组合导航滤波器估计轨迹仍跟踪原始参考轨迹,达到了卫星导航欺骗的目的。本文提出的基于逐点拉偏式卫星导航欺骗干扰技术可用于保障重点区域/人员的低空安全防护。     

北斗车辆自适应组合导航技术研究

车辆在“城市峡谷”、高架桥下、隧道等环境利用北斗卫星导航系统进行导航过程中,存在卫星导航信号易受遮挡和干扰的局限性.将北斗卫星导航系统同惯性导航系统、里程计等传感器进行组合,运用Kalman滤波技术进行多传感器的信息融合,能够较好地提高导航精度以及导航系统整体的自主性、抗干扰性、容错性和可靠性.针对现有车辆导航系统可靠性不高的问题,着重对基于Kalman滤波的北斗车辆自适应组合导航可靠性进行了相关研究.     

利用并行多处理器的卫星自主导航方法研究

提出卫星导航系统采用两个并行处理器PⅠ、PⅡ.其中PⅡ首先利用批处理估计器估计卫星初始状态,然后利用高精度轨道动力学模型预报下一周期的卫星星历,并将星历数据存储于星上.而PⅠ则依据上一周期的各种数据,采用实时轨道预报算法提供卫星当前时刻的轨道信息.基于这一分工思路,利用卫星观测到的星光折射信息,在高、中、低各种轨道上进行了卫星自主定轨的计算机数学仿真,仿真结果证实了并行多处理器导航计算机结构及相应导航算法用于卫星自主导航的可行性及有效性.     

面向区域导航增强的低轨卫星星座设计

部署低轨导航卫星是对现有卫星导航系统的有效补充,是实现导航增强的重要途径。研究了低轨卫星的星座设计问题,面向区域导航增强的应用需求,采用基于椭圆轨道的星座设计方案,利用卫星在椭圆轨道远地点运动速度慢、覆盖区域大、相对地面滞留时间长等特点,提升其对局部区域的覆盖能力。此外,在Flower星座框架下优化每颗卫星的轨道参数,确保其星下点轨迹重复经过重点区域的中心,延长卫星相对于给定区域的过顶时间。有效改善了过顶时间、覆盖重数、空间几何分布等影响导航性能的关键指标。在以北斗3号系统为导航增强对象的仿真对比中发现,在低轨卫星数量相同的条件下,该文的卫星星座设计方案具有更好的导航增强性能。     

高速率GNSS电文多进制编码调制技术

为解决导航电文信息速率制约导航系统性能的问题,提出了一种基于码移键控调制和多进制低密度奇偶校验码的新型全球卫星导航系统（GNSS）信号编码调制技术.在-130 dBm的接收电平、误码率不大于10^-7的指标下,该技术可以达到1 500 bit/s的有效信息速率,并且具有信号结构简单、与现有GNSS信号兼容性强等优势.理论分析和仿真结果证明,该技术突破了现有卫星导航信号体制下的信息速率极限,能够克服复杂信号结构造成的难以独立捕获跟踪的问题,在卫星导航系统中有比较重要的实用价值.     

伪卫星空中基站定位高性能算法研究

伪卫星作为卫星导航系统的重要增强手段,能够克服卫星系统在导航定位及武器精确制导方面存在的缺点。针对伪卫星空中基站位置不易精确确定的问题,设计了临近空间伪卫星空中基站定位SINS/CNS/SAR组合导航系统,建立了组合导航非线性数学模型;在吸收抗差自适应滤波、高斯滤波和粒子滤波优点的基础上,提出了一种抗差自适应高斯混合Sigma点粒子滤波算法。将提出的算法应用于SINS/CNS/SAR自主导航系统进行计算仿真,并与Unscented卡尔曼滤波和粒子滤波比较,结果表明:提出的新算法能够满足伪卫星空中基站自主导航定位的需求,导航精度明显高于Unscented卡尔曼滤波和粒子滤波算法。     

上海华测导航技术股份有限公司

正简介上海华测导航技术股份有限公司(简称"华测导航")致力于为用户提供高精度数据的采集和应用解决方案,专业从事高精度卫星导航定位相关软硬件技术产品的研发、生产和销售,主要产品包括高精度全球导航卫星系统(GNSS)接收机、地理信息系统(GIS)数据采集器、海洋测绘产品、三维激光产品、无人机遥感产品等数据采集设备,以及位移监测系统、农机自动导航系统、北斗地基增强系统等数据应     

基于国产容器云平台的北斗仿真系统设计与实现

北斗卫星导航系统为我国自主研发的全球卫星导航系统,已在多个领域得到广泛应用。近来年网络安全事件的频繁发生,对航天领域的安全提出了较大挑战,目前其仿真平台大部分基于x86架构,迫切需要构建一套自主可控的北斗卫星仿真模拟环境。针对低轨卫星模拟环境的国产化需求,提出基于国产容器云平台的北斗导航仿真应用的设计思路和实现方法,运用容器云微服务发布和集群负载功能提高了系统的高可用性和高效性,解决国产环境性能瓶颈和IO传输瓶颈。通过北斗导航仿真模拟实验验证了低轨卫星应用系统基于国产容器云平台的正确性和适用性,对于加速航天模拟仿真系统国产化替代、推动航天领域向自主可控方向的迈进具有重大意义。     

现阶段北斗卫星导航系统可用性分析

导航系统可用性是系统在某一区域内提供可用导航服务能力的重要指标。通过对实验区域（０°Ｎ-６０°Ｎ,６０°Ｅ-１５０°Ｅ）内１°×１°格网点２４ｈ中截止角对导航系统ＰＤＯＰ可用性的影响和５°截止角下卫星可见性、系统可用性的详细分析,得出了我国现阶段北斗卫星导航系统在时间、空间上可用性的分布规律。初步分析表明,取截止角为５°时系统可用性＞９８％,实验区域内,卫星可见性和可用性已能够较好满足我国以及邻近区域内的定位和导航需求。     

军转民推广技术

多模多频卫星导航产品检测技术 技术开发单位 中国空间技术研究院第五一四研究所 技术简介 基于该技术开发的卫星导航产品检测系统支持北斗、GPS、格洛纳斯、伽利略等四大卫星导航系统的星座及信号体制,可进行射频信号的有线测试和无线测试,能够满足导航芯片、模块及其组成的导航型、授时型和测量型卫星导航接收机的测试需要,符合我国北斗卫星导航系统产业化发展趋势.目前,该技术已成功应用于交通运输、安全生产、气象等行业,以及北斗重大专项领域的卫星导航产品检测工作中.     

“3S”技术的最新发展

现在,“3S”技术已经在经济社会的发展中发挥着重要作用.今后几年,GPS和GLONASS两个卫星导航定位系统将被更新换代,其精度和抗干扰能力也将大幅度提高.有中国参与的欧洲Galileo卫星导航定位系统已进入实质性部署阶段,将于2010年前后建成,从而打破美国目前在这一领域的垄断局面.遥感科技将向高分辨率、多平台、定量化、网络化和实用化发展.GIS将与计算机科技协同发展,在三维空间分析与表达、空间数据的不确定性、多源数据集成或融合、空间多尺度数据挖掘等方面受到更多关注,并走向网络化、大众化,成为地理信息产业的重要组成部分.     

抗差自适应EKF在INS/GNSS紧组合中的应用

针对惯性/卫星紧组合导航中卫星观测数据存在粗差,影响组合导航系统定位精度,同时考虑到卫星少于4颗和卫星几何分布不佳对预测残差构造自适应因子的影响,提出了一种抗差自适应EKF紧组合算法。该算法给出惯性/卫星紧组合状态方程与观测方程,抗差等价权因子和预测残差法构造自适应因子的计算公式,并给出卫星少于4颗和卫星几何状态分布不佳情况下自适应因子的计算方法。通过车载实测数据对算法进行验证与分析,实验结果表明,基于抗差自适应EKF的惯性/卫星紧组合算法可有效削弱卫星粗差观测值的影响,在可见卫星数少于4颗和卫星几何分布不佳的状态下,依据该算法获取的系统导航精度得到进一步提高。     

基于粗糙模糊集理论的卫星导航系统作战效能评估方法

针对卫星导航系统在信息化战争中的地位与作用,提出了一种基于粗糙集和模糊集理论的作战效能评估方法——粗糙模糊集理论,并对粗糙模糊集理论的算法进行了分析和设计,建立了卫星导航系统作战效能评估指标体系.最后结合实例,运用粗糙模糊集理论对卫星导航系统作战效能进行了评估,给出了效能评估的决策规则.     

New autonomous celestial navigation method for lunar satellite

Celestial navigation system is an important autonomous navigation system widely used for deep space exploration missions, in which extended Kalman filter and the measurement of angle between celestial bodies are used to estimate the position and velocity of explorer. In a conventional cartesian coordinate, this navigation system can not be used to achieve accurate determination of position for linearization errors of nonlinear spacecraft motion equation. A new autonomous celestial navigation method has been proposed for lunar satellite using classical orbital parameters. The error of linearizafion is reduced because orbit parameters change much more slowly than the position and velocity used in the cartesian coordinate. Simulations were made with both the cartesiane system and a system based on classical orbital parameters using extended Kalman filter under the same conditions for comparison. The results of comparison demonstrated high precision position determination of lunar satellite using this new m     

A novel satellite-equipped receiver for autonomous monitoring of GNSS navigation signal quality

Global navigation satellite system (GNSS) comes with potential unavoidable application risks such as the sudden distortion or failure of navigation signals because its satellites are generally operated until failure. In order to solve the problems associated with these risks, receiver autonomous integrity monitoring (RAIM) and ground-based signal quality monitoring stations are widely used. Although these technologies can protect the user from the risks, they are expensive and have limited region coverage. Autonomous monitoring of satellite signal quality is an effective method to eliminate these shortcomings of the RAIM and ground-based signal quality monitoring stations; thus, a new navigation signal quality monitoring receiver which can be equipped on the satellite platform of GNSS is proposed in this paper. Because this satellite-equipped receiver is tightly coupled with navigation payload, the system architecture and its preliminary design procedure are first introduced. In theory, code-tracking loop is able to provide accurate time delay estimation of received signals. However, because of the nonlinear characteristics of the navigation payload, the traditional code-tracking loop introduces errors. To eliminate these errors, the dummy massive parallel correlators (DMPC) technique is proposed. This technique can reconstruct the cross correlation function of a navigation signal with a high code phase resolution. Combining the DMPC and direct radio frequency (RF) sampling technology, the satellite-equipped receiver can calibrate the differential code bias (DCB) accurately. In the meantime, the abnormities and failures of navigation signal can also be monitored. Finally, the accuracy of DCB calibration and the performance of fault monitoring have been verified by practical test data and numerical simulation data, respectively. The results show that the accuracy of DCB calibration is less than 0.1 ns and the novel satellite-equipped receiver can monitor the signal quality effectively.     

Research on assessment method of intrasystem and intersystem of the global navigation satellite system

The global navigation satellite system(GNSS) has become an important space infrastructure. Following GPS and GLONASS, Europe and China have been building their own global navigation satellite system, respectively, GALILEO and Compass. In order to consolidate the leadership of GPS in the globe, United States is gradually upgrading the traditional GPS. Simultaneously, Russia is also intensively restoring full performance of GLONASS. With the advancement of international satellite navigation system, satellite navigation frequency resources are already in short supply, and the design and use of the navigation signals are more sophisticated and complex due to commercial, disaster relief and other reasons. Since there may be many navigation signals in the same basic bandwidth, the coexistence of multiple systems and the combined application make intersystem mutual interference become the focus research. Under this background, the satellite navigation system mutual interference evaluation system needs to be established urgently to meet and support the compatibility and interoperability of the GNSS system. In the paper, through the performance analysis of the GNSS signal acquisition, carrier tracking, data demodulation and code tracking, the equivalent carrier to noise ratio model based on spectrum isolation coefficient is established, and the theoretical system of the GNSS signal mutual interference is proposed according to the mechanism, and the mutual interference of GPS, GALILEO and Compass system is analyzed and assessed.     

双天线对消技术对宽带干扰的抑制性能

提出了一种应用在卫星导航系统中的干扰对消技术.通过理论推导,详细分析了干扰对消系统对宽带干扰抑制能力的极限值,揭示了带宽延时积与干扰对消比的内在关系,量化了幅度误差和相位误差对宽带干扰对消比的恶化程度.通过仿真和实验验证了理论分析的正确性.实验验证了双天线对消系统可使卫星导航接收机的抗干扰能力提高29 dB.