平流层飞艇机载风速测量方法

Stratospheric airship airborne velocity measurement

风场数据是平流层飞艇实现长时驻空和飞行控制的重要参数。针对平流层空气稀薄、传统机载压力式测风速方法测量精度低等问题,提出一种利用激光雷达直接探测技术的平流层飞艇机载风速测量方法。设计了基于直接探测原理的多普勒激光雷达测风速系统,构建了分别以FP(IFabry-Perot干涉仪)和MZ(IMach-Zehnder干涉仪)为鉴频器的条纹成像技术的风速反演数学模型,并进行了数值仿真分析。结果显示,在355 nm波长出射激光和20 m/s径向风速条件下,FPI-条纹成像技术与MZI-条纹成像技术的径向风速测量误差分别为11.0%和6.5%,测量分辨率分别为1.90 m/s和1.62 m/s,表明该方法能够满足平流层飞艇机载风速测量要求。

The wind field data are important input parameters for the stratospheric airship in the long-time loiter and the flight control. In view of the thin air in the stratosphere and the low precision of the pitot tube, a direct detection method based on LIDAR is proposed. A Doppler lidar velocity measurement system based on the direct detection principle is designed. The wind velocity inversion mathematical model of the two fringe imaging techniques is built and numerical simulations are carried out. It is shown that the measurement errors of the Fabry-Perot etalon（FPI） and the Mach-Zehnder interferometer（MZI） are 11.0% and 6.5%, respectively, at 355 nm output laser and20 m/s wind speed. And the velocity resolution of the two methods are 1.9 m/s and 1.6 m/s, respectively. The results indicate that the new method can effectively meet the requirements of the stratospheric airship wind speed measurement.