下击暴流

Downburst is an outburst strong wind on or near the ground, and its field characteristics are significantly different from boundary layer winds.

下击暴流是雷暴天气产生的近地面短时强风，具有和大气边界层近地风显著不同的风场特征，其风荷载数值模拟方法也和常规风荷载模拟方法不同。

The wind convergence, mesoscale cyclone and vertical wind shear at lower levels may produce heavy rainfall. The mesoscale cyclone and vertical wind shear at middle and upper levels may produce strong downburst or hails.

低层水平风的辐合、中气旋、垂直风向切变等可以产生强降水，中高层的中气旋、垂直风切变可以产生下击暴流、冰雹等强对流天气。

The characteristics of microburst and its modeling requirements in real time flight simulation were analyzed.

分析了微下击暴流的特征和用于飞行实时仿真中的建模需求。

An axisymmetric,three-dimensional engineering model of microburst was used in the simulation of aircraft take-off with windshear encounter.

采用较真实的三维微下击暴流工程化模型和非线性动态逆方法，对飞机在起飞过程中的纵向/横侧改出低空风切变的控制律进行了设计和仿真。

Wind shear ; microburst ; turbulence ; model.

风切变；微下击暴流；湍流；数学模型

The emphasis in this composition is windshear signal processing technology. Some processing methods are introduced in detail, they are suppressing clutter,extracting windshear parameters,computing hazard factor and etc..The signal processing simulation is accomplished on computer, it includes simulating microburst echo signal,simulating ground clutter echo signal,filtering clutter,estimating wind speed and calculating hazard factor.

本文重点研讨了风切变信号处理技术，对杂波抑制技术、风切变特征参数提取技术及危险因子计算方法等内容进行了深入的研究，并进行了计算机模拟，包括微下击暴流回波信号模拟、地杂波回波信号模拟、杂波抑制、风速提取和危险因子计算。

Results show that using bin to bin automatic gain control,clutter filtering,and suitable antenna tilt management,the " wet " microburst windshear can be accurately detected 80s(approximately 6km) in front of the aircraft,meeting the certification requirements proposed by FAA.

结果表明：通过单元－单元自动增益控制、杂波滤波和天线仰角控制，可提前80s（6km）探测到&湿&微下击暴流风切变，符合FAA提出的适航要求

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。