X射线脉冲星信号时延估计方法研究

发布时间：2018-07-11 16:37

本文选题：X射线脉冲星信号 + 轮廓折叠　；参考：《西安电子科技大学》2013年硕士论文

【摘要】：脉冲星是一种快速自转的中子星，最显著的特性是其辐射信号周期具有极高的稳定性。这一特性使脉冲星能够为在近地轨道、地球同步轨道、大椭圆地球轨道、地月轨道、星际空间飞行以及深空飞行的航天器提供位置、速度和时间等丰富的导航信息。因此X射线脉冲星导航定位具有极为重要的军事用途和广阔的工程应用前景。在X射线脉冲星导航定位系统中，观测脉冲轮廓与标准脉冲轮廓模板的时间延迟是十分重要测量数据，本文基于脉冲星X射线信号的长期稳定度，对时间延迟量的准确获取进行了多种时延估计方法的比较，包括互相关法，非线性最小二乘法和自适应滤波法，同时研究了基于分数阶傅里叶变换的时延估计方法应用于脉冲星领域的可行性。分别采用标准正弦信号，脉冲星信号地面模拟系统产生的信号对几种时延估计方法进行了仿真研究，最后采用REXE卫星采集到的真实X射线脉冲星信号进行算法验证。仿真结果表明，，基于分数阶傅里叶变换的时延估计方法在一定程度上提高了时延估计的性能，而时延估计性能的提高直接减小了航天器在脉冲星导航系统中的定位误差。
[Abstract]:Pulsar is a fast rotating neutron star. The most remarkable characteristic is that its radiation signal period is extremely stable. This feature enables pulsars to provide abundant navigation information for spacecraft in low Earth orbit, geosynchronous orbit, large elliptical Earth orbit, Earth Moon orbit, interstellar space flight and deep space flight. Therefore, X-ray pulsar navigation and positioning has very important military applications and broad engineering application prospects. In the X-ray pulsar navigation and positioning system, the time delay between observing the pulse profile and the standard pulse contour template is very important. Based on the long-term stability of the pulsar X-ray signal, A variety of time delay estimation methods are compared, including cross-correlation method, nonlinear least square method and adaptive filtering method. At the same time, the feasibility of time delay estimation based on fractional Fourier transform in pulsar field is studied. Several time delay estimation methods are simulated using standard sinusoidal signal and pulsar signal ground simulation system. Finally, the real X-ray pulsar signal collected by REXE satellite is used to verify the algorithm. The simulation results show that the time delay estimation method based on fractional Fourier transform improves the performance of time delay estimation to a certain extent, and the performance of time delay estimation directly reduces the positioning error of spacecraft in pulsar navigation system.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P128.4;P145.6

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