In the evening of 30 august 1998 , an area of thunderstorms passed from west to east across chek lap kok . the tdwr detected microbursts near the northern runway of the airport , with the computed windshear magnitude in agreement with measurements of surface anemometers 日傍晚，一个雷雨区正从西向东横过赤角，机场多普勒天气雷达探测到机场北跑道附近有微下击暴流，而计算出的风切变强度与地面风速表量度数据相乎。
In the evening of 30 august 1998 , an area of thunderstorms passed from west to east across chek lap kok . the tdwr detected microbursts near the northern runway of the airport , with the computed windshear magnitude in agreement with measurements of surface anemometers 日傍晚，一个雷雨区正从西向东横过赤?角，机场多普勒天气雷达探测到机场北跑道附近有微下击暴流，而计算出的风切变强度与地面风速表量度数据相乎。
As an example , under the windshear conditions depicted in the figure below where there is a windshear event of 15kt at 3 mile final and a microburst event of 30kt at 1 mile final , the consolidated windshear alert based on the first encounter , maximum intensity principle will be 下图例子显示跑道进场3海里处出现了15海里小时风切变的事件，于1海里处同时出现- 30海里小时的微下击暴流。根据"首次相遇位置最大强度"的准则，风切变预警应为：
Microbursts induced by thunderstorms microburst is the most violent form of downdraft from a thunderstorm . it is characterized by an intense and localized descent of cool air , causing a sudden outflow of horizontal winds above the ground with a typical horizontal extent of a few kilometres 微下击暴流是由雷暴引致的一种最猛烈的下沉气流，其特徵是一团强烈而局部的冷空气下沉，引致地面上出现突如其来在水平方向往外扩散的风，范围通常达数千米。
Microbursts induced by thunderstorms microburst is the most violent form of downdraft from a thunderstorm . it is characterized by an intense and localized descent of cool air , causing a sudden outflow of horizontal winds above the ground with a typical horizontal extent of a few kilometres 微下击暴流是由雷暴引致的一种最猛烈的下沉气流，其特徵是一团强烈而局部的冷空气下沉，引致地面上出现突如其来在水平方向往外扩散的风，范围通常达数千米。
The idea is that the microburst or windshear alerts passed by the air traffic controllers to the pilots should include the location i . e . runway or 1 , 2 or 3 nautical miles from runway threshold of the first encounter of the microburst or windshear event i . e . first encounter and the maximum value of the computed wind speed difference i . e . maximum intensity 这准则的构思是，所有经航空交通管制员传递给飞机师们的微下击暴流预警或风切变预警，均包含首次相遇微下击暴流或风切变事件的位置即跑道或离跑道入口两端1海里2海里或3海里的地方以及计算风速差别的最大数值即最大强度。
The idea is that the microburst or windshear alerts passed by the air traffic controllers to the pilots should include the location ( i . e . runway or 1 , 2 or 3 nautical miles ( nm ) from runway threshold ) of the first encounter of the microburst or windshear event ( i . e . first encounter ) and the maximum value of the computed wind speed difference ( i . e . maximum intensity ) 这准则的构思是，所有经航空交通管制员传递给飞机师们的微下击暴流预警或风切变预警，均包含首次相遇微下击暴流或风切变事件的位置即跑道或离跑道入口两端1海里、 2海里或3海里的地方以及计算风速差别的最大数值即最大强度。
Pilots not familiar with this alerting principle may be caught by surprise when on approaching the airport they first experience a gain event windshear of 15 kt instead of a loss event microburst of - 30 kt at the first encounter 3 mile final location only to encounter a loss of - 30 kt a couple of seconds later at 1 mile final 他们在三海里处首次相遇位置所遇到的，并不是风速减少的情况- 30海里/小时的微下击暴流，而是风速增加的情形+ 15海里/小时的风切变。而于数秒后到达最后进场1海里处却遇到- 30海里/小时的风速减少情况。
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 . from the simulated results , a dangerous windshear is detected 5o ~ 78s , so the radar performance meets the certification requirements proposed by faa and nasa 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。
