The following is an example . around noon on august 21 , 2002 , the lidar detected windshear near the western part of the airport . this enables the aviation forecaster to issue an alert an hour or so in advance 以下是一個實例:在二二年八月二十一日中午1 2時,激光雷達(dá)探測到機場西面地方出現(xiàn)風(fēng)切變,并能讓預(yù)報員提早一小時多發(fā)出預(yù)警。