利用非GEO卫星进行地面站时间同步研究

根据地球静止轨道（GEO）卫星转发同步信号的双向时间比对法实现站间时间同步的基本原理,提出了利用拟合非GEO卫星转发信号的伪距实现时间同步的新方法。拟合伪距法消除了传播路径延迟和只能使用GEO卫星作为信号转发器的限制,扩大了双向时间比对的应用范围。仿真结果表明：该法有较高的精度,满足工程要求。     

激光制导武器的对抗技术研究

激光制导是目前制导精度最高的导引技术之一,在分析其原理和特点的基础上,探讨对抗激光制导武器的方法和技术,包括激光侦查、高重频激光干扰、激光致盲等。     

空间太阳能电站聚光模式研究

空间太阳能电站是指能够在轨道上将太阳能通过工程技术手段有效采集、转化并传输到地面,再转化成为电能供地面使用的系统。聚光是空间太阳能收集的途径之一,多种SSPS方案采用了聚光方式。文章介绍了聚光式SSPS的研究现状,对现有SSPS方案中的不同聚光技术方案进行了综述分析,将空间太阳能电站聚光技术划分为3个层次,总结成4种模式,详细分析了每种模式的优点与技术难点,并对聚光式空间太阳能电站的发展提出建议。     

黄金周热点景区拥堵现象分析与对策研究

2012年中秋国庆黄金周期间,国内大部分热点景区接待的游客数量不仅大大超过了景区最佳承载量,也严重超过了景区的最大承载量,出现了游客严重拥堵的现象,在一定程度上影响了游客的旅游质量,破坏了景区的自然环境和人文环境,并带来一系列安全隐患。文章旨在探究此现象形成的机理及后果,并对解决这一问题提出相应对策。     

天基激光告警设备的极低虚警率技术研究

造成天基激光告警设备虚警的外部因素包括空间电磁辐射和高能带电粒子辐射,内部因素是探测和放大电路的噪声。而通过合理的光学滤波设计、检测和放大电路设计、信号处理设计和各种抗辐照设计等措施,可实现天基激光告警设备的极低虚警率指标。     

Precise orbit determination using the batch filter based on particle filtering with genetic resampling approach

In this study, genetic resampling (GRS) approach is utilized for precise orbit determination (POD) using the batch filter based on particle filtering (PF). Two genetic operations, which are arithmetic crossover and residual mutation, are used for GRS of the batch filter based on PF (PF batch filter). For POD, Laser-ranging Precise Orbit Determination System (LPODS) and satellite laser ranging (SLR) observations of the CHAMP satellite are used. Monte Carlo trials for POD are performed by one hundred times. The characteristics of the POD results by PF batch filter with GRS are compared with those of a PF batch filter with minimum residual resampling (MRRS). The post-fit residual, 3D error by external orbit comparison, and POD repeatability are analyzed for orbit quality assessments. The POD results are externally checked by NASA JPL’s orbits using totally different software, measurements, and techniques. For post-fit residuals and 3D errors, both MRRS and GRS give accurate estimation results whose mean root mean square (RMS) values are at a level of 5 cm and 10–13 cm, respectively. The mean radial orbit errors of both methods are at a level of 5 cm. For POD repeatability represented as the standard deviations of post-fit residuals and 3D errors by repetitive PODs, however, GRS yields 25% and 13% more robust estimation results than MRRS for post-fit residual and 3D error, respectively. This study shows that PF batch filter with GRS approach using genetic operations is superior to PF batch filter with MRRS in terms of robustness in POD with SLR observations.     

中国无地面控制点摄影测量卫星追述（二）--1∶1万传输型摄影测量卫星技术思考

以1∶1万传输型摄影测量卫星工程有效载荷配置为基础,分析了传输型测绘卫星中影响定位精度的误差源,提出了激光测距数据辅助两线阵卫星影像处理的若干思路,并进行了模拟仿真试验。试验结果表明：利用激光测距数据参与两线阵影像光束法平差,能有效改善航线模型系统变形,并保持较小的上下视差,可满足卫星影像无地面控制点条件下1∶1万高精度定位要求。     

Photon counting detector for space debris laser tracking and lunar laser ranging

We are reporting on a design, construction and performance of solid state photon counting detector package which has been designed for laser tracking of space debris. The detector has been optimized for top photon detection efficiency and detection delay stability. The active area of the commercially available avalanche photodiode manufactured on Si (SAP500 supplied by Laser Components, Inc.) is circular with a diameter of 500 μm. The newly designed control circuit enables to operate the detection sensor at a broad range of biases 5–50 V above its breakdown voltage of 125 V. This permits to select a right trade-off between photon detection efficiency, timing resolution and dark count rate. The photon detection efficiency exceeds 70% at the wavelength of 532 nm. This is the highest photon detection efficiency ever reported for such a device. The timing properties of the detector have been investigated in detail. The timing resolution is better than 80 ps r.m.s, the detection delay is stable within units of picoseconds over several hours of operation. The detection delay stability in a sense of time deviation of 800 fs has been achieved. The temperature change of the detection delay is 0.5 ps/K. The detector has been tested as an echo signal detector in laser tracking of space debris at the satellite laser station in Graz, Austria. Its application in lunar laser ranging is under consideration by several laser stations.     

A new approach to the telescope operation method for satellite tracking using a time synchronization technique

For the development of a telescope that is capable of precisely tracking satellites and high-speed operation such as satellite laser ranging, a special method of telescope operation is required. This study aims to propose a new telescope operation method and system configuration for the independent development of a mount and an operation system which includes the host computer. Considering that the tracking of a satellite is performed in real time, communication and synchronization between the two independent subsystems are important. Therefore, this study applied the concept of time synchronization, which is used in various fields of industry, to the communication between the command computer and the mount. In this case, communication delays do not need to be considered in general, and it is possible to cope with data loss. Above all, when the mount is replaced in the future, only the general communication interface needs to be modified, and thus, it is not limited by replacement in terms of the overall system management. The performance of the telescope operation method developed in this study was verified by applying the method to the first mobile SLR system in Korea. This study is significant in that it proposed a new operation method and system configuration, to which the concept of time synchronization was applied, for the observation system that requires an optical telescope.