部分模糊度固定方法在GNSS/INS紧组合中的应用研究

针对动态环境下GNSS/INS导航定位模糊度固定难的问题,提出了一种基于部分模糊度固定的GNSS/INS紧组合导航定位算法,通过选择模糊度的最优子集进行固定,并利用实测车载实验进行了算法验证.实验结果表明:在开阔环境下,基于部分模糊度固定的GNSS/INS紧组合与基于全模糊度固定的GNSS/INS紧组合算法的定位精度相...     

微纳InSAR卫星总体技术研究

微纳合成孔径雷达干涉(Synthetic Aperture Radar Interferometry, InSAR)卫星是对地定量化遥感的重要手段。开展了微纳InSAR卫星系统总体技术研究，给出了使得干涉测量覆盖范围最大的双星编队构型设计方法，建立了低燃料消耗双星轨道参数设计准则，提出高功能密度比InSAR卫星系统的设计方法，包括载荷平台一体化、卫星高集成模块化等总体设计方法，并给出了相应的设计实例。     

静止轨道实孔径微波载荷卫星构型方案研究

静止轨道实孔径微波载荷可实现全天时、全天候、高频次云雨大气观测，是台风、流域性强降水等致灾天气预报的重要手段。由于技术难度和研制经费等原因，世界上尚无在轨应用的先例。针对实孔径微波载荷系统集成度高、机械尺寸和跨距大，以及静止轨道卫星需要携带大容量燃料贮箱的问题，从准光学系统内嵌卫星平台、三贮箱平铺和天线统筹布局等3个总体系统层面，提出实孔径微波载荷与平台一体化构型，并研制了卫星结构星和载荷工程样机。通过地面试验验证了该构型方案，为静止轨道微波探测卫星研制打下了坚实的基础，也可为后续卫星提供借鉴。     

基于多维数值积分的高阶确定采样型滤波方法

基于多维数值积分讨论了确定采样型滤波器,这一类滤波器的不同之处体现在对滤波器中均值和方差的计算,这一问题与数值积分密切相关.针对以往确定采样型滤波器在提高滤波精度的同时会增加计算量,通过分析高斯权值积分,采用完全对称积分公式,计算积分节点、节点个数及权重,相比高斯厄米特滤波减少了计算量,同时滤波精度可达到五阶以上.选取典型算例对新的滤波方法仿真分析,验证了该滤波方法的可行性和有效性.     

混合并联TBCC动力的冲压流道跨声速流动及阻力特性

为了探究跨声速飞行工况下混合并联涡轮基组合循环（Turbo based combine cycle，TBCC）动力的冲压流道在冷通气状态下的流动及阻力特性，构建了一个巡航马赫数为4.0、基于混合并联TBCC动力的高马赫数飞机模型，通过三维定常数值模拟方法研究了其在Ma_∞=0.7~1.6，H_∞=11 km飞行环境下飞机-发动机内/外流动及其耦合特征。计算结果表明：跨声速状态下，冲压进气道入口处气流增压后的静压达到了自由来流滞止压力的85%~90%，气流接近于滞止状态，说明组合进气道存在强烈的节流效应，且冲压通道的喉道是组合进气道节流效应的主要贡献者；冲压发动机尾喷管的排气流动同时受到飞机绕流及涡轮通道排气系统等多方面的干扰，且涡轮通道排气射流对冲压发动机尾喷管气流本身就存在膨胀压缩及排气引射等多种干扰机制。阻力分析表明，压差阻力系数高出内表面摩擦阻力系数2个数量级，是跨声速状态下冲压流道阻力的主要来源；亚声速状态下，进气道阻力占比达到了60%~80%，是冲压流道的主要阻力部件，而Ma_∞>1.0超声速状态下，进气道阻力占比随飞行马赫数的增大而逐步减小，尾喷管的阻力则快速增长，阻力贡献逐渐向尾喷管转移，两者趋于接近。     

通导一体化概念框架与关键技术研究进展

通导一体化是综合PNT体系发展的重要组成部分和关键方向。对通信导航一体化的概念进行了探讨，提出了通信导航弹性融合的概念框架。面向综合PNT体系需求，设计了通导一体网络化PNT系统架构，阐述了通导一体化关键技术的研究进展，从通导一体化信号、信道、接收处理、网络架构、网络管理等多个角度进行了全面系统的梳理和分析；介绍了低轨通导融合、区域自组网通导融合、5G+UWB协同等典型成果，并对网信场图、智能网管、博弈对抗等通导一体化技术未来发展方向进行了展望。     

基于改进POCET技术的通导一体化信号设计

随着低轨卫星组网的发展,结合我国北斗三号全球卫星导航系统的全面建成,研究兼容北斗的通信导航一体化技术日益迫切。为使卫星上的高功率放大器工作在非线性饱和区,以达到较高的发射功率效率,需要保证合成信号的恒包络特性。考虑北斗导航信号与低轨卫星通信信号频点不同,且待复用信号分量较多,以相位优化恒包络发射(POCET)技术为基础,提出了一种改进的多频点多非独立信号分量恒包络复用技术,对七路信号进行复用,利用罚函数进行目标函数优化得到最优解。通过分析其信号特性,表明该方法具有较高的复用效率,并能有效抑制非独立分量造成的波形畸变,从而实现通信导航一体化信号设计,为未来基于低轨卫星的通信导航一体化波形设计提供了思路。     

Tight integration of BDS-3/BDS-2/GPS/Galileo observations considering the new overlapping DISBs and its application in obstructed environments

Tight integration can enhance the model strength and positioning performance by considering the characteristic of differential inter-system bias (DISB), especially in obstructed environments. However, limited work emphasizes the comprehensive analysis of five-frequency DISBs between BDS-3 and other systems considering the receiver type, receiver configuration, and antenna type. In addition, the overlapping DISBs between BDS-3 and BDS-2 are also in great demand for further investigation since they are often regarded as one system. In this study, one DISB-float model is introduced to estimate the DISBs, and one DISB-fixed model and one DISB-free model are formulated to enhance the model strength of tight integration. Four dedicated datasets were collected to estimate the DISBs, which are also comprehensively analyzed considering the receiver type, receiver configuration, and antenna type. The results show that the DISBs between BDS-3 and other systems are rather stable over a certain period and are related to the receiver type and receiver configuration, whereas are not related to the antenna type. More interestingly, the B1I code DISB between BDS-3 and BDS-2 exhibits significant magnitude with a mean value of ?1.44 m for the baseline composed of two different receivers. In this case, the B1I code DISB must be considered and the tight integration between BDS-3 and BDS-2 considering its calibration can improve the positioning performance. Besides, the tight integration of the DISB-fixed model can significantly improve the positioning accuracy between multiple GNSS. Compared to the loose integration, the improvement of 60.6 %, 56.6 %, and 61.2 % can be obtained in the E, N, and U directions, when only two satellites are available for each system. In real obstructed environments, the tight integration of the DISB-free model can also improve the positioning performance in terms of positioning availability and accuracy, as well as the ambiguity resolution performance.     

Mahalanobis distance-based fading cubature Kalman filter with augmented mechanism for hypersonic vehicle INS/CNS autonomous integration

Inertial Navigation System/Celestial Navigation System(INS/CNS) integration, especially for the tightly-coupled mode, provides a promising autonomous tactics for Hypersonic Vehicle(HV) in military demands. However, INS/CNS integration is a challenging research task due to its special characteristics such as strong nonlinearity, non-additive noise and dynamic complexity.This paper presents a novel nonlinear filtering method for INS/CNS integration by adopting the emerging Cubature Kalman Filter(C...