导航电文对定位性能的敏感度分析和验证

发布时间：2018-04-27 12:11

本文选题：导航电文 + 敏感度分析　；参考：《电子科技大学》2017年硕士论文

【摘要】：随着人们对GPS依赖程度的增加,GPS的安全性问题逐渐凸显出来,因而需要分析各类干扰和偏差对定位性能的影响。除了使用传统宽带或窄带干扰信号外,发送带有虚假导航电文信号的GPS欺骗信号也是一种常见干扰模式。由于后者更具欺骗性和隐蔽性,难以被察觉,对GPS安全性影响极大。在这种情况下,本文按照导航电文参数对定位性能的敏感程度对其进行分类,重点监测和防护敏感的电文参数,从而有效保护GPS的脆弱环节,提升系统的安全性。为此,本文开展GPS导航电文对定位性能的敏感度分析和验证。首先,通过敏感度分析获知当某个电文参数出现扰动或被恶意篡改后,在定位结果上可能产生的偏差。具体而言,以时间电文参数和星历参数为切入点,综合利用一阶线性近似的方法对非线性定位方程进行转换和处理,推导出电文参数偏差和定位偏差之间的定量关系,据此判断定位性能对某个电文参数的敏感度,并对定量关系式的适用条件进行了分析。其次,对敏感度分析的正确性和有效性进行两个层面的仿真验证。一方面生成修改电文参数的错误信号源,验证上述定量关系式的正确性以及其适用条件,在该信号源中并不包含真实的卫星信号。另一方面则是构造电文被修改的欺骗信号源,其中真实信号和虚假信号同时存在,基于生成式欺骗干扰中伪码滑动的原理牵引接收机跟踪上虚假信号,根据定位结果评估敏感度分析的使用价值。最终为提升GPS安全性的研究提供支撑。
[Abstract]:With the increasing of people's dependence on GPS, the security problem of GPS becomes more and more important, so it is necessary to analyze the influence of all kinds of interference and deviation on the positioning performance. In addition to traditional wideband or narrowband interference signals, GPS spoofing signals with false navigation message signals are also a common interference mode. Because the latter is more deceptive and hidden, it is difficult to detect, which has a great impact on GPS security. In this case, this paper classifies navigation message parameters according to their sensitivity to positioning performance, and focuses on monitoring and protecting sensitive message parameters, so as to effectively protect the vulnerable links of GPS and enhance the security of the system. Therefore, the sensitivity of GPS navigation message to positioning performance is analyzed and verified. First, the sensitivity analysis is used to find out the possible deviation in the location result when a message parameter is disturbed or maliciously tampered with. In particular, with the time message parameter and ephemeris parameter as the breakthrough point, the first order linear approximation method is used to transform and process the nonlinear positioning equation, and the quantitative relationship between the message parameter deviation and the positioning deviation is deduced. The sensitivity of location performance to a message parameter is judged, and the applicable conditions of quantitative relationship are analyzed. Secondly, the correctness and validity of sensitivity analysis are verified by two levels of simulation. On the one hand, an error signal source which modifies message parameters is generated to verify the correctness of the above quantitative relationship and its applicable conditions, and the true satellite signal is not included in the signal source. On the other hand, it is to construct the spoofing signal source that the message is modified, in which the real signal and the false signal exist at the same time. Based on the principle of pseudo-code sliding in the generated spoofing interference, the receiver tracts the false signal. The utility value of sensitivity analysis was evaluated according to the location results. Finally, it provides support for the research of improving the security of GPS.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN967.1;P228.4

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