Development of a random modulation bistatic meteor radar system for mesospheric wind measurement

本研究的目的是利用连续波伪随机调制技术研制双基地布置流星雷达，用于中流层顶（约80-100km）的风测量。本研究利用双基地流星雷达测量风的技术发展要素是测量无线电波传播时间、多普勒频移和反射点方向矢量。结果如下：1。传播时间从接收信号和发射码之间的相关函数达到最大时的延迟时间开始计算。对这些原理和sn比进行了计算机仿真，并进行了实时流星探测的高速相关实验。为了精确测量多普勒频移和延迟时间，研制了GPS接收机和锁相环频率标准装置。在此基础上，进行了GPS卫星时间同步精度测量实验，得到了较好的同步精度小于1 μ.s.3。在接收端设置干涉仪，通过天线间的相位差测量流星回波的到达方向。通过计算机仿真，在考虑天线间相互阻抗的情况下，发现了最优的天线组合可以安装在更小的场地上。对干涉仪进行了测量实验，得到了满意的方向精度，误差小于5度。

This research aimed at developing meteor radar of bistatic arrangement using the CW pseudo random modulation technique for the wind measurement of the mesospause region (about 80-100km). The technological development elements of this research to measure wind with bistatic meteor radar are measuring propagation time of the radio wave, Doppler shift, and the direction vector of the reflection point. The results are as the following.1. Propagation time is measured from the delay time when a correlation function becomes the biggest with the receiving signal and the transmittion code. Computer simulation about these principles and the SN-ratio, and the experiment of high-speed correlation for the meteor detection in real time were done.2. For the accurate measurement of Doppler shift and the delay time, GPS receivers and PLL frequency standard devices were developed. Furthermore, the measurement experiment of the time synchronous accuracy by the GPS satellite was done for the accurate time synchronism, and it got satisfactory synchronous accuracy less than 1 μ.s.3. An interferometer is composed on the receiving side, and the arrival direction of the meteor echo was measured from a phase differences between the antennas. The optimun antennas composition was found that it could be installed in the smaller site than before considering mutual inpedance between the antenna by the computer simulation. The measurement experiment of the interferometer was done and we got satisfactory direction accuracy less than 5 degrees.