基于FFT算法的脉冲到达时间延迟测量

The Offset Measurement of Pulse Time of Arrival Based on FFT Algorithm

脉冲到达时间（TOA）是脉冲星导航解算中的基本观测量，其精度直接影响着脉冲星导航精度。脉冲到达时间延迟一般通过将观测脉冲轮廓与标准轮廓进行互相关计算求得，但该算法依赖于脉冲轮廓的时间分辨率。本文研究了一种基于频域傅里叶变换（FFT）的脉冲TOA求解算法，推导了相应计算公式，并采用仿真数据和RXTE卫星实测数据进行了试验分析。研究结果表明，基于FFT的算法得到了准确的脉冲轮廓时间延迟，能应用于空间实测数据处理中，但该方法对噪声水平比较敏感。

Pulse time of arrival （TOA） is the basic observation in the calculation of pulsar navigation and its precision affects the accuracy of pulsar navigation directly. The pulse TOA delay is generally caleulated by cross correlation between observed pulse contour and standard contour, while the algorithm depends on the temporal resolution of the pulse contour. In this paper, the pulse TOA algorithm based on FFT is studied and a corresponding calculation formula is deduced. Then the experimental analysis is made using the simulation data, measurement data and RXTE satellite test data. The results show that the algorithm based on FFF can obtain accurate pulse contour time delay and be applied in spatial measured data processing, but it is more sensitive to noise level.