遥感相机次镜组件等效模型的研究

试验模态分析在航空航天领域结构力学的研究中得到广泛的应用,而且起到相当重要的作用。文章探讨了较易破损或是比较昂贵结构的试验模态分析方法－等效模型法。该方法是基于理论和结构灵敏度分析,研究原型与等效模型材料不同时的等效模型研制方法。这一方法被应用于某遥感相机的次镜组件的模态试验分析,得到了较好的结果。     

Spatial and temporal monitoring of drought conditions using the satellite rainfall estimates and remote sensing optical and thermal measurements

Drought is an important natural disaster that causes devastating impacts on the ecosystem, livestock, environment, and society. So far, various remote-sensing methods have been developed to estimate drought conditions, each of which has advantages and restrictions. This study aims to monitor the real-time drought indices at the field scales via the integration of various earth observations. Our proposed method consists of two steps. In the first step, the relationships between long-term standardized precipitation indices (SPI) derived from PERSIANN-CDR rainfall data and two drought-dependent parameters derived from MODIS products, including normalized NDVI and soil-air temperature gradient, are obtained at the spatial resolution of PERSIANN-CDR grid (approximately 25 km). As the next step, the corresponding relationships are applied to estimate the drought index maps at the spatial resolution of MODIS products (1 km). Numerous analyses are carried out to evaluate the proposed method. The results revealed that, from various drought indices, including SPIs of different timescales (1, 3, 6, and 12-months), SPI-3 and SPI-6 are more appropriate to the proposed method in terms of correlation with temperature and vegetation parameters. The findings also demonstrate the competency of the proposed method in estimating SPI indices with average RMSE 0.67 and the average correlation coefficient of 0.74.     

国际空间站有效载荷集成流程分析

国际空间站（ISS）针对有效载荷从论证、研制到随ISS飞行的过程建立了标准集成流程和精益集成流程两种模式,这两种模式互为补充,有效支持了ISS载荷随飞行任务的滚动实施。在有效载荷集成过程中,NASA采用多线并行的方式,其集成流程从理念上不完全等同于传统卫星有效载荷随飞行任务实施的研制流程,并设置有效载荷集成经理,架设有效载荷管理方、研制方和研究团队之间的桥梁。通过对国际空间站有效载荷集成过程的深入分析,提出可供我国空间站有效载荷集成借鉴的经验,如提供快速集成流程、加强有效载荷集成管理、强化有效载荷全寿命周期管理等。     

一种光学遥感成像系统优化设计新方法研究

针对空间光学高分辨率遥感器,既要实现轻小型化,又要获得高品质遥感图像的要求,文章提出一种空间光学遥感成像系统优化设计新方法;综合考虑成像链路各环节因素,采用全面的指标设计和合理的优化设计流程来改进空间光学遥感成像系统的总体指标和成像品质,并显著降低遥感器的研制难度.通过比较全链路优化设计方法和传统设计方法的仿真结果及其...     

挠性高稳定度卫星载荷扰动力矩补偿研究

有效载荷或星上运动部件相对卫星平台转动引入的扰动力矩严重影响卫星平台的姿态稳定度和指向精度.为满足卫星姿态高稳定度要求,采用正余弦细分驱动原理对帆板驱动机构(SADA)细分,并利用力矩补偿机构补偿有效载荷运动所引入的扰动力矩.此外,针对补偿机构自身存在的摩擦力矩设计补偿控制律,以改善其力矩输出性能.仿真算例表明设计方案有效.     

Feasibility assessment of optical technologies for reliable high capacity feeder links

Space telecom scenarios like data relay satellite and broadband/broadcast service providers require reliable feeder links with high bandwidth/data rate for the communication between ground station and satellite. Free space optical communication (FSOC) is an attractive alternative to microwave links, improving performance by offering abundant bandwidth at small apertures of the optical terminals. At the same time Near-Earth communication by FSOC avoids interference with other services and is free of regulatory issues. The drawback however is the impairment by the laser propagation through the atmosphere at optical wavelengths. Also to be considered are questions of eye safety for ground personnel and aviation. In this paper we assess the user requirements for typical space telecom scenarios and compare these requirements with solutions using optical data links through the atmosphere. We suggest a site diversity scheme with a number of ground stations and a switching scheme using two optical terminals on-board the satellite. Considering the technology trade-offs between four different optical wavelengths we recommend the future use of 1.5 µm laser technology and calculate a link budget for an atmospheric condition of light haze on the optical path. By comparing link budgets we show an outlook to the future potential use of 10 µm laser technology.     

远距离测试发控系统中数字光纤通信系统的接口设计及实现

远距离分布式计算机网络测试发控系统是当今国际宇航事业发展的方向。数据通信系统能否畅通、准确、实时、可靠是实现远距离测试发控的关键。本文列举了光纤通信的优点，分析了通信中常用纠错编码的优劣，提出一种既符合测试发控系统的特点又适合光纤通信要求的新的纠错编码方案，并设计出以该纠错编码为核心的数字光纤通信接口，满足了一个特定的远距离测试发控系统对数字通信的要求。     

定标系统光源控制电路设计

文章介绍了某型号定标系统光源控制电路的设计。     

典型R-C系统主光学装置的热光学分析

文章采用热光学集成法对典型R-C成像系统某主光学装置进行热光学分析。     

CBERS-1卫星红外多光谱扫描仪主光学装置设计

文章介绍了CBERS -1卫星IRMSS主光学装置的设计 ,叙述了光学系统和结构选择、装配调试、像质的稳定性、可靠性问题。该装置在焦面Φ8mm范围内弥散园优于Φ0.010mm ,调制传递函数MTF优于0.91。