高重频激光对激光导引头干扰性能的研究

对高重频激光干扰激光半主动制导武器导引头的性能进行了理论分析。用陀螺稳定式激光导引头作为稳定跟踪系统,实验验证了高重频激光的干扰效果。最后,提出了采用这种干扰方法的一些实际问题。     

固体火箭发动机推力终止过程的数值分析

本文指出,在大、中型固体火箭发动机的推力终止过程中,打开反向喷管(或辅助排气孔)必定导致产生一系列强度相当大的压力脉冲,而现有的理论分析均不能预估和解释这一现象。本文提供了一组冷模拟实验结果,讨论了产生压力脉冲的原因,提出了估算其强度的方法,并且应用特征线法和激波拟合法进行一维非定常流动的数值计算,发展了一种能够同时预估压力脉冲强度的内弹道计算程序。预估结果与实验曲线吻合良好。     

液体火箭发动机火药起动器性能设计及考核

详细论述了液体火箭发动机火药起动器的性能设计方法,并论述了火药起动器在极限情况(高温高燃速、低温低燃速)下性能的考核方法.最后,通过应用实例对上述火药起动器的性能设计及考核方法进行了验证.     

数显油滴测试仪

本文介绍了一种数显油滴测试仪,对所用的传感器原理及电路要点作了重点阐述。     

光栅的衍射在高分辨力测长仪器中的应用研究

选用高密度光栅产生衍射条纹 ,研究其信号合成、采集及处理的方法以实现在长度计量中 ,纳米分辨力的计数。     

1553B总线接口单元构成的研究

分析了超大规模集成电路(VLSI)专用芯片COM1553 B的功能和接口信号,并论述用COM1553 B设计总线接口单元(BIU)的方法。给出结构框图和直接存储器存取(DMA)方式交换信息的设计思想。按此方法设计的BIU,具有通用性好、可靠性高和良好的软件接口的特点。     

Characterizing slope correction methods applied to satellite radar altimetry data: A case study around Dome Argus in East Antarctica

Slope correction is important to improve the accuracy of satellite radar elevation measurements by mitigating the slope-induced error (SE), especially over uneven ground surfaces. Although several slope correction methods have been proposed, guidance in the form of stepwise algorithm on how to implement these methods in processing radar altimetric data at the coding level, and the differences among these methods need to be presented and discussed systematically. In this paper, three existing types of slope correction methods—the direct method (DM), intermediate method (IM), and relocation method (RM, further divided into RM1 and RM2)—are described in detail. In addition, their main differences and features for various scientific applications are analyzed. We conduct a systematic experiment with CryoSat-2 Low Resolution Mode (LRM) data in a physically stable area around Dome Argus in East Antarctica, where in-situ measurements were available for comparison. The slope correction is implemented separately using the three methods, with the latest high-accuracy Reference Elevation Model of Antarctica (REMA) as the a-priori topography model. The bias and precision of the slope-corrected CryoSat-2 data results from the RM2 is ?0.18 ± 0.86 m based on the comparison with the field Global Navigation Satellite System (GNSS) data. The results from the RM2 indicate higher precision compared to those from the RM1. According to the correlation analysis of the slope-corrected CryoSat-2 data results (RM1 and RM2), the bias enlarges and the precision becomes worse when the surface slope increases from 0 to 0.85°. After a comprehensively comparative analysis, we find that the results from the RM1 and RM2 are superior in precision (0.93 m and 0.86 m) with respect to the GNSS data. The relatively low precision (1.22 m) from the IM is due to the potential error from the a-priori digital elevation model (DEM). The DM has the lowest precision (2.66 m). Another experiment over rough topography in West Antarctica is carried out for comparison, especially between the RM1 (precision of 15.27 m) and RM2 (precision of 16.25 m). In general, the RM is recommended for the SE elimination among the three methods. Moreover, the RM2 is firstly considered over smooth topography due to the superior performance in bias and precision, while the RM1 is more suggested over the rough topography because of the slightly smaller bias and better precision. The IM relies much on the accuracy of the a-prior DEM and is not usually recommended, because of the strict requirement in the sampling time between the radar altimetry data and the a-priori DEM to avoid any surface change over time.     

基于温度参数的经验密度模式修正方法

大气阻力是影响低轨航天器众多空间操作的重要因素,尤其是经验密度模式,固有的至少15%的误差已经严重制约航天器轨道计算精度的提高。针对广泛应用的经验密度模式,选择物理背景简明的Jacchia71模式,以温度参数Tc和Tx为对象,建立密度相对于上述温度参数的条件方程,推导了密度相对于温度参数的解析偏导数,并给出其最小二乘解。利用CHAMP卫星数据对模式修正结果进行验证,模式平均误差从40%降低至3%左右。通过TG01飞行器的轨道预报比较,修正前后轨道预报误差从2 km降低至1.3 km。经过CHAMP卫星和TG01飞行器的实测数据检验,验证了修正算法的正确性和有效性。     

编制设计模版提高设计质量

分析航天型号研制工作中继承性、延续性、规范化对设计模版编制的迫切需求,阐述设计模版编制的原则、形式与内容、编制要求等以及设计模版的完善与应用情况,介绍一部开展设计模版分批编制的经验与体会.     

人控交会对接控制方法研究

追踪器上的航天员根据摄像机的图像手动操作手柄完成目标器和追踪器的对接任务,为了减轻航天员负担,提高人控对接成功率,文章提出的思路是姿态控制采用自动控制,使得追踪器姿态和合作目标器姿态保持一致,航天员只负责相对位置控制。文章给出了航天员的相对位置控制策略,并将全系数自适应控制和PID控制方法用于追踪器的姿态控制。仿真结果表明,采用全系数自适应控制进行姿态控制过渡过程时间短、稳态精度高,有利于航天员完成人控对接的任务。