一种便携式激光测云仪的云底高度反演方法

Portable lidar ceilometer for cloud-base height measurement

报道了新研制的一种便携式激光测云仪,该设备由光学、电子和机械三部分组成,采用单片机处理回波信号、识别云底高度,并给出了该激光测云仪的相关参数。将回波斜率突增点作为云底定义点,利用云回波在上升斜率、脉冲宽度和幅度上与大气回波及噪声脉冲间的差异,识别反演出云底高度。另外,同一位置连续测量数次,可以剔除干扰噪声。与计数式激光测云仪进行了实测比较,数据基本吻合。结果表明:便携仪的云高识别算法基本合理、可行,便携仪中所采用的剔除大气回波伪信号算法能提高系统的测低云性能,智能识别算法能滤除干扰噪声。最后,需要对算法进行进一步的优化。

The algorithm of a portable lidar ceilometer for cloud-base height measurement was developed. The zero-crossing of lidar return slope was considered the location of the cloud base. Since the cloud was different from the atmosphere in random noise in the slope and intensity and pulse width of the backscatter returns, the cloud base height could be determined by analyzing the difference of lidar returns carefully. The random noise could be eliminated by detecting cloud continuously on the same location. The measured data by portable lidar eeilometer were compared with that by traditional count eeilomenter and they agreed well.