一种定时序列同步干扰效能评估方法

卫星通信对抗中干扰效能的准确评估对于优化干扰样式具有十分重要的作用,传统的误码率评估技术在卫星通信的电子对抗试验中具有一定的局限性.对此,采用基于隐匿帧锁定状态转换的干扰效能评估方法,分析了定时序列状态转换与误码率之间的对应关系,并通过仿真验证了该方法的有效性与实用性.这对于卫星通信电子对抗试验中的干扰效果评价体系的建立具有重要意义.     

起始点位置偏差对精密GPS差分定位影响的研究

从理论上讨论了起始点位置误差对ＧＰＳ基线解算精度的影响,并对实测资料进行了模拟计算,得到了与理论计算值相吻合的结果。指出：ＧＰＳ网中起始点的位置偏差不影响基线解的内部精度,但使ＧＰＳ基线解产生系统性偏差,偏差的大小与起始点位置偏差的大小成正比,与基线平均纬度的正切函数值成正比。文章最后,对在“ＳＡ”和“ＡＳ”技术影响下,进行高精度ＧＰＳ差分定位时,如何测定网中具有较高精度的ＷＧＳ８４坐标起始点问题,提出了建议。     

Timing and sex effects on the “Spatial Orientation Test”: A World War II map reading test

The present study aimed to document the psychometric properties of a recently declassified map reading test used in World War II, known as the Spatial Orientation Test (SOT), which measures mostly the ability to match map and aerial images. We also examined the influence of timing conditions and sex of the participants as correlates of performance. A total of 101 participants (41 males, 60 females) completed the SOT, along with other spatial tests and spatial affect scales (tapping spatial anxiety and confidence). Results showed a significant male advantage on this rediscovered map reading test. Additionally, timing affected overall performance but not the magnitude of sex differences. Finally, significant correlations were found between the SOT and other spatial tests and scales. The processes underlying this test and its potential for future use are discussed.     

无介质硅压阻式压力/压差传感器的研制CSCD

目前,硅压阻式压力/压差传感器在伺服系统上得到广泛的应用。但是由于其内部压力敏感芯体的封装结构为薄膜隔离式,其内部硅油的密封性是伺服系统配套传感器长期带压贮存的软肋。根据伺服系统对压力/压差传感器的需求,研制了几种无介质压阻式压力/压差传感器,其内部避免了硅油介质传递压力,保证了传感器的可靠性。通过传感器原理结构的研究,以及其性能指标的测试和对比,为伺服系统配套传感器提供了新的选择。     

Guidance laws for attacking defended target

In this paper, two new guidance laws based on differential game theory are proposed and investigated for the attacker in an attacker-defender-target scenario.The conditions for the attacker winning the game are analyzed when the target and defender using the differential game guidance law based on the linear model.The core ideas underlying the two guidance laws are the attacker evading to a critical safe boundary from the defender, and then maintaining a critical miss distance.The guidance law more appropriate for the attacker to win the game differs according to the initial parameters.Unlike other guidance laws, when using the derived guidance laws there is no need to know the target and the defender's control efforts.The results of numerical simulations show that the attacker can evade the defender and hit the target successfully by using the proposed derived guidance laws.     

半直接配点法在航天器追逃问题求解中的应用

采用半直接配点法求解时间固定两航天器追逃问题，提出一种新的数值求解追逃双方最优控制策略的方式，避免了求解非线性两点边值问题。在两航天器均为连续小推力假设条件下，以终端距离为支付函数，给出了半直接配点法求解此追逃问题的过程。在此数值方法中，根据半直接转换将微分对策问题转化为一个最优控制问题，由Gauss-Lobbato配点法最终将此最优问题转化为非线性规划问题，继而通过序列二次规划方法求解。这种半直接配点法避免微分对策问题最优策略的必要条件(两点边值问题)求解，并且数值稳定性好。数值仿真给出了追逃双发的最优控制策略和相应的追逃轨迹。     

一种用于空间翻滚目标接近控制的相对运动建模方法

针对空间翻滚目标等一类相对运动复杂的接近控制问题，首先重点研究了基于微分几何理论的相对运动建模，建立视线旋转坐标系下的三维相对运动方程；然后将三维相对运动解耦为视线瞬时旋转平面内的相对运动和该平面的转动，建立了统一的控制器设计框架，形式统一简洁、物理意义明确，消除传统制导与控制策略中俯仰、偏航通道的耦合因素影响；最后通过六自由度仿真算例证明，相对运动模型物理意义明晰、鲁棒性强、控制精度高、工程实现容易。     

基于相频约束的航天器定时技术

双向相干测距测速体制是最常用的航天器测量体制,是一种闭环体制.与之相比较,开环测距测速可以在信号更微弱的情况下获取到观测量,在深空任务中有着独特的意义.然而,开环测距也面临棘手的技术难题——高精度航天器定时技术.针对该难题,在保持现有航天器信号体制的基础上,阐述了基于遥测信号和测距侧音信号（差分单向测距DOR信号可看作侧音信号）间相频约束的航天器定时原理,研究了侧音频率最优化设计方法,给出了“器上发射测站接收”的初步实现方案,为后续开展工程应用奠定了基础.     

Estimation and analysis of GPS receiver differential code biases using KGN in Korean Peninsula

The total electron content (TEC) estimation by the Global Positioning System (GPS) can be seriously affected by the differential code biases (DCB), referred to as inter-frequency biases (IFB), of the satellite and receiver so that an accuracy of GPS–TEC value is dependent on the error of DCBs estimation. In this paper, we proposed the singular value decomposition (SVD) method to estimate the DCB of GPS satellites and receivers using the Korean GPS network (KGN) in South Korea. The receiver DCBs of about 49 GPS reference stations in KGN were determined for the accurate estimation of the regional ionospheric TEC. They obtained from the daily solution have large biases ranging from +5 to +27 ns for geomagnetic quiet days. The receiver DCB of SUWN reference station was compared with the estimates of IGS and JPL global ionosphere map (GIM). The results have shown comparatively good agreement at the level within 0.2 ns. After correction of receiver DCBs and knowing the satellite DCBs, the comparison between the behavior of the estimated TEC and that of GIMs was performed for consecutive three days. We showed that there is a good agreement between KASI model and GIMs.     

Precise control of a magnetically suspended double-gimbal control moment gyroscope using differential geometry decoupling method

Precise control of a magnetically suspended double-gimbal control moment gyroscope (MSDGCMG) is of vital importance and challenge to the attitude positioning of spacecraft owing to its multivariable, nonlinear and strong coupled properties. This paper proposes a novel linearization and decoupling method based on differential geometry theory and combines it with the internal model controller (IMC) to guarantee the system robustness to the external disturbance and parameter uncertainty. Furthermore, by introducing the dynamic compensation for the inner-gimbal rate-servo system and the magnetically suspended rotor (MSR) system only, we can eliminate the influence of the unmodeled dynamics to the decoupling control accuracy as well as save costs and inhibit noises effectively. The simulation results verify the nice decoupling and robustness performance of the system using the proposed method.