[Objective] The aim was to study the formation and development of a heavy snow in Benxi area. [Method] Based on conventional meteorological data, the formation and development of a heavy snow in Benxi area from Decemb...[Objective] The aim was to study the formation and development of a heavy snow in Benxi area. [Method] Based on conventional meteorological data, the formation and development of a heavy snow in Benxi area from December 4th to 5th in 2009 were analyzed from the aspects of weather situation evolution and physical quantity field feature. [Result] The heavy snow was caused by upper trough and North China cyclone. In this process, there was upper level divergence and lower level convergence over Benxi area, and it was warm at low attitude and cold at high attitude; southwest jet at low attitude transported water vapor from Bohai Sea to eastern Liaoning, which provided good water vapor condition for snow, but it didn’t reach heavy snow due to inadequate ascending force. The development of Ural Mountains high ridge played an important role in the snow process and the strengthened high ridge moving northward was beneficial to the southward movement of cold air and deepening of upper trough. Analysis on physical quantity field could provide reference for predicting beginning and ending time and strength of heavy snow. [Conclusion] The study could provide basis for the forecast of heavy snow.展开更多
针对传统战场态势认知过程中缺乏对作战区域的有效分析与识别的问题,提出了一种面向作战区域提取的空战场目标轨迹分析方法。首先,基于改进Douglas-Peucker算法对目标原始轨迹进行特征点提取,得到目标特征轨迹,从而降低目标轨迹冗余信息...针对传统战场态势认知过程中缺乏对作战区域的有效分析与识别的问题,提出了一种面向作战区域提取的空战场目标轨迹分析方法。首先,基于改进Douglas-Peucker算法对目标原始轨迹进行特征点提取,得到目标特征轨迹,从而降低目标轨迹冗余信息;其次,利用密度峰值快速搜索聚类算法(Clustering by Fast Search and Find of Density Peaks,CFSFDP)对目标特征轨迹进行聚类分析,得到多个特征点簇,最后,基于Graham凸包算法对每个特征点簇进行扫描,进而得到闭合的多边形来表征作战区域。通过若干案例仿真验证了该算法模型的可行性和有效性。展开更多
文摘[Objective] The aim was to study the formation and development of a heavy snow in Benxi area. [Method] Based on conventional meteorological data, the formation and development of a heavy snow in Benxi area from December 4th to 5th in 2009 were analyzed from the aspects of weather situation evolution and physical quantity field feature. [Result] The heavy snow was caused by upper trough and North China cyclone. In this process, there was upper level divergence and lower level convergence over Benxi area, and it was warm at low attitude and cold at high attitude; southwest jet at low attitude transported water vapor from Bohai Sea to eastern Liaoning, which provided good water vapor condition for snow, but it didn’t reach heavy snow due to inadequate ascending force. The development of Ural Mountains high ridge played an important role in the snow process and the strengthened high ridge moving northward was beneficial to the southward movement of cold air and deepening of upper trough. Analysis on physical quantity field could provide reference for predicting beginning and ending time and strength of heavy snow. [Conclusion] The study could provide basis for the forecast of heavy snow.
文摘针对传统战场态势认知过程中缺乏对作战区域的有效分析与识别的问题,提出了一种面向作战区域提取的空战场目标轨迹分析方法。首先,基于改进Douglas-Peucker算法对目标原始轨迹进行特征点提取,得到目标特征轨迹,从而降低目标轨迹冗余信息;其次,利用密度峰值快速搜索聚类算法(Clustering by Fast Search and Find of Density Peaks,CFSFDP)对目标特征轨迹进行聚类分析,得到多个特征点簇,最后,基于Graham凸包算法对每个特征点簇进行扫描,进而得到闭合的多边形来表征作战区域。通过若干案例仿真验证了该算法模型的可行性和有效性。
