【作者】 梁明珠；

【导师】 吴洪宝； 汤达章；

【作者基本信息】 南京信息工程大学 ， 气象学， 2005， 硕士

【摘要】 本文利用多普勒天气雷达体扫数据资料计算了垂直累积液态含水量——VIL,通过实例对VIL和降水的关系作了分析。把VIL大值中心区(VIL中心区)作为降水中心的自动识别、跟踪和移动预报因子。在识别VIL中心区时,利用了三个阈值:VIL核心阈值、参考初始阈值以及面积阈值,所采用的识别方法是逐步增大阈值法。利用事先规定的面积阈值来识别VIL中心区是本文识别技术的特点。采用权重定位法对VIL中心区进行定位。对VIL中心区跟踪时,作为对面积比法的改进,本文使用了动态预测面积比法。同时启用了分类跟踪法和中心区面积控制方法,并引入了类似于分团的交叉中心区。在移动预报方面,利用矩心法计算中心区或交叉中心区的移动速度,用矢量合成法对多个时段的移动速度进行矢量合成,对矢量合成速度的方向和多个时段的平均速度方向利用线性集成法进行了线性集成。采用线性外推法对中心区的位置和移动速度进行线性外推预报。并开发出一套自动化程度很高的系统软件,可以实现以上所涉及的全部功能。实例结果表明:所采用的因子——VIL具用良好的保守性;所使用的方法能很好地识别、跟踪和预报VIL中心区。所开发的软件,界面友好、操作方便、自动化程度高、运行速度快、稳定性很高,完全可以投入实时业务运行,并值得推广应用。更多还原

【Abstract】 VIL is calculated based on the volume-data of Doppler weather radar. The connection between VEL and precipitation is analysized. VIL heartland is regarded as the tool of precipitation heartland in identification, tracking and motion forecasting.In identification of VIL heartland, there threshold-value is used, such as VIL kernel threshold-value, reference original threshold-value and area threshold-value. The method of gradually increasing original threshold-value is employed in identification. The peculiarity of identification is area threshold-value which is used to identify VIL heartland. The location of VIL heartland is orientated by its barycenter.In tracking, method of motorial forecasting on area-ratio is employed, which roots in improved area-ratio. Method of classification and mass-conservation principle is also employed in tracking. Across-heartland is introduced which is similar to disparted group. In motion forecasting, motion velocity is calculated by heartland or across heartland through method of sqyare-center. Many motion velocity in recent different time is composed through method of vector compound. The heading of composed velocity and average heading of those velocity is linearly integrated. The method of linear extrapolation is employed to linearly forecast the locatin and motion velocity of VIL heartland.The correlated software is programed by ourself, which include function of all above method and function of well automatization. The result shows VIL possess nicer conservative quality and these method can be useful tool for the identification, tracking and motion forecasting of VIL heartland. The software has friendly interface, high automatization of running, short period of running and better stability. It is simple to operate this software. It could be used in real time and be applied abroadly.更多还原