基于时延扩展的主动测高算法

Active Altimetry Algorithm Based on Time Delay Extension

无线电高度计能给飞行平台提供精确的高度信息,不仅能保证平台平稳、安全飞行,还能便于定位处理。常见的测高方法采用提取回波前沿的方法来测高,不仅精确度不高,回波信号也利用不全。在主动测高的模型下,采用宽波束照射到地面,信号经地面反射后到达接收机,由于地面照射圆具有一定的面积,将地面划分成多个等距离环。在波束指向存在偏角时,提出了时延扩展的测高方法,讨论偏角对测高结果的影响。利用面目标的时延扩展对波束偏角进行判定和估计,并测量偏角,进而得到高度测量值。即利用最短回波时延和最长回波时延测量波束偏角和平台高度。通过仿真验证了该算法比传统算法具有更高的测高精度。

The radio altimeter can provide accurate altitude information to the flight platform,which can not only guarantee the stable and safe flight of the platform,but also facilitate the positioning and processing.The common altimetry method uses the method of extracting the echo front to measure the height.Not only the accuracy is not high,but also the echo signal is not fully utilized.Under the model of active height measurement,the wide beam is used to irradiate the ground,and the signal reaches the receiver after reflection from the ground.Since the irradiated circle on the ground has a certain area,the ground is divided into multiple equidistant rings.A time-delay extension altimetry method is proposed when the beam is pointing at a deviation angle,and the effect of the deviation angle on the altimetry result is discussed.The beam deviation angle is judged and estimated by the time-delay extension of the surface target,and the deviation angle is measured,and then the height value is obtained.The shortest echo delay and the longest echo delay are used to measure the beam deviation angle and the platform height.The simulation results show that the proposed algorithm has higher precision than the traditional algorithm.