【作者】 张娟；

【导师】 李鹏；

【作者基本信息】 西安电子科技大学 ， 信号与信息处理， 2006， 硕士

【摘要】 多普勒导航系统是一种自主导航系统。连续波体制多普勒雷达有着体积小、重量轻、发射频谱窄、无高度空穴、无速度模糊和测频精度高等优点，非常适合作为直升飞机的机载导航雷达使用。连续波多普勒雷达的测频精度决定了其测速精度，而在数字化系统中测频精度又是由其频谱估计算法决定的。本文首先介绍了多普勒导航雷达的基本工作原理；然后对信号DFT谱估计算法改进的可行性进行了论证；其次给出了几种DFT谱的改进算法，并提出了一种有效的频谱估计算法——局部频谱连续细化算法；接着讨论了连续波雷达直漏信号的产生原因、影响及其零频抑制技术；最后分析了数字化连续波体制多普勒雷达系统，建立了信号模型，并对前面给出的频谱估计算法做了仿真研究，其中作者提出的局部频谱连续细化算法的性能较为良好，符合本系统的指标要求。更多还原

【Abstract】 Doppler navigator is an autonomous guidance system. The continuous wave Doppler navigation radar is used as the airborne navigation radar in heliogyro because of the virtues such as small in size and weight, narrow frequency band used in emission, high precision in the estimate of frequency, neither the altitude hole nor the ambiguity speed, and so on. The precision of speed measured by the continuous wave radar is affected significantly by the frequency precision, which is determined by a spectrum estimation algorithm.Firstly, the principles of work in the Doppler navigation radar are introduced in this paper.Secondly, deduce the improvability of the signal DFT spectrum estimation algorithm. Moreover, an effective spectrum estimation algorithm, continuous zoom in local spectrum algorithm, is proposed based on the research of several improved DFT spectrum estimation methods.Thirdly, the generation reasons and influences of the leak signals in the continuous radar are discussed, and several methods for suppressing leak interference are given.Lastly, construct the signal model based on the analysis of the digitized Doppler navigation radar system. Furthermore, a set of simulations on the spectrum estimating algorithms illustrated that the proposed estimating algorithm is effective, and suitable to the index requirement of the digitized Doppler navigation radar.更多还原