卫星振动对光通信系统捕获概率的影响研究

发布时间：2018-07-09 18:42

本文选题：卫星光通信 + 小卫星　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：本文针对卫星平台振动对捕获概率的影响进行分析并展开研究。在超窄信标空间捕获背景下,允许采用超窄光学信标光的激光通信终端。根据目前已有的文献调研显示,卫星捕获扫描过程中,卫星平台振动是决定瞄准、捕获跟踪过程是否稳定的一个重要原因。然而过去研究的一般为低轨和高轨道卫星振动对捕获性能的影响,而对于小卫星捕获时振动环境恶劣,振动幅值大的情况并没有具体研究。本文则是在小卫星的振动环境下提出了一种针对小卫星扫描捕获时发生振动后的捕获概率公式,并对此公式进行了仿真分析验证其正确性,这是首次针对小卫星平台振动对捕获概率的影响进行建模和分析,具体工作如下所示。首先介绍了卫星光通信的发展过程,并且调研了卫星平台振动国内外的研究现状。详细介绍了卫星空间捕获理论以及单场扫描捕获方案,并对目前已有的捕获概率推导公式做了分析研究。其次在卫星随机振动环境下对捕获扫描建立理论模型。从卫星平台的特点出发,对卫星平台随机振动后的扫描捕获过程建立方位俯仰(θh,θv)坐标系。本文假定的随机振动在这两个角方向上的概率服从独立的高斯分布,此外,由于非常高的振动水平是不现实的,但是却因为使推导更完整而被提出来。不考虑接收部分,本文以获得捕获成功的标准是在给定时刻指向计数器终端的方向限定的强度水平,通过对比以往的卫星振动后的捕获概率本文所提出的对于小卫星振动后的捕获概率更加具体。最后通过以上所推导的捕获概率与振动水平的关系在计算机环境下进行理论仿真分析。仿真曲线分别从接收端位置、光束束散角与扫描螺距比例出发从仿真后的曲线图可以得出扫描在不确定区域内随着振动水平的增大捕获概率会有不同的变化趋势但最后都趋于平衡。在第四章中对第三章的仿真曲线进行了蒙特卡洛仿真分析进一步证明了所推导的公式正确性。并通过公式推导得到了振动趋于零时的捕获概率趋于1。对于大幅度的振动水平时的捕获概率在第四章进行了重新的推导计算,并与第三章所推导的公式对比发现所估计的捕获概率是可信的。本论文相比与过去的振动后捕获概率的分析更加具体,为平台振动后的捕获概率分析设计了更有效的方案,在国内首次对小卫星扫描振动的影响进行建模分析。
[Abstract]:In this paper, the influence of satellite platform vibration on capture probability is analyzed and studied. In the background of ultra-narrow beacon space acquisition, a laser communication terminal with ultra-narrow optical beacon light is allowed. According to the existing literature research, the vibration of satellite platform is an important reason to determine whether the tracking process is stable or not in the process of satellite acquisition and scanning. However, in the past, the effects of low-orbit and high-orbit satellite vibration on the acquisition performance were generally studied. However, there was no specific study on the condition that the vibration environment was bad and the vibration amplitude was large when the small satellite was captured. In this paper, a probability formula for small satellite scanning acquisition is proposed under the small satellite vibration environment, and its correctness is verified by simulation analysis. This is the first time to model and analyze the effect of the vibration of a small satellite platform on the capture probability. Firstly, the development process of satellite optical communication is introduced, and the research status of satellite platform vibration at home and abroad is investigated. The theory of satellite space acquisition and the scheme of single field scanning acquisition are introduced in detail, and the existing formulas of acquisition probability are analyzed and studied. Secondly, the theoretical model of capture scanning is established in the environment of satellite random vibration. Based on the characteristics of the satellite platform, the azimuth (胃 h, 胃 v) coordinate system is established for the scanning acquisition process of the satellite platform after random vibration. In this paper, the probability of the random vibration in these two angular directions is assumed to be independent of the Gao Si distribution. In addition, because the very high vibration level is unrealistic, it is proposed because the derivation is more complete. Regardless of the receiving part, the criteria for obtaining success in this paper are the intensity levels defined at a given time in the direction of the counter terminal, By comparing the previous acquisition probability after satellite vibration, this paper proposes a more specific capture probability for small satellite vibration. Finally, the relationship between the capture probability and the vibration level is analyzed in the computer environment. The simulation curve is located from the receiving end, Based on the ratio of beam divergence and scanning pitch, it can be concluded from the simulation curve that the acquisition probability of scanning varies with the increase of vibration level in the uncertain region, but it tends to balance finally. In the fourth chapter, the simulation curve of chapter 3 is analyzed by Monte Carlo simulation, and the formula is proved to be correct. The acquisition probability of the vibration approaching 00:00 is obtained by formula derivation. The acquisition probability of large amplitude vibration level is recalculated in chapter 4, and compared with the formula derived in chapter 3, it is found that the estimated capture probability is credible. Compared with the previous analysis of capture probability after vibration, this paper designs a more effective scheme for the analysis of the acquisition probability after vibration of the platform, and models and analyzes the influence of small satellite scanning vibration for the first time in China.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.1

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