能见度自动观测系统性能对比及分析

1998年6月至9月间在北京进行了一次透射表能见度仪与前向散射式能见度仪的对比试验。参加试验的能见度自动观测系统有：透射表两套、前向散射能见度仪一套和双光路前向散射能见度仪两套。五套参试仪器分别被安装在南苑机场南北向主跑道的东侧。试验收集数据的起止时间为1998年7月25日09h至8月25日08h，时间间隔为1min。从总体误差分布分析，VAISALA公司的前向散射FD－12表现最好；其次是跑道中段的PRESENTEY公司的PEP9012双光路前向散射仪；而传统上认为测量结果较好的MITRAS透射表在高能见度时表现均不佳。所有参试仪器在能见度低于2000m时表现都不错，能见度4000m以上时，散射仪的测量值明显偏高。因此可以认为能见度在4000m以下时，参试的五套仪器均能满足航空气象保障要求，4000m以上测量结果的离散性较大，不确定性均大，但对飞行安全影响也较小，可以作为参考使用。

COMPARISON AND ANALYSIS OF PROPERTY OF VISIBILITY AUTOMATIC OBSERVATION INSTRUMENTS

It had put up a compare examination between two types of visibility instruments.There are five sets of visibility instruments during the test.It includes two sets of transmission meter,one set of forward scattering meter and two sets of cross double light way forward scattering meter.They were set up along the East Side of runway in NanYuan airport in Beijing.Test data of one minute were collected for one month from July 25 to August 25 in 1998. The analysis of gross result of test is that the type FD-12 forward scattering meter of Vaisala Co.Ltd is best.The type PEP9012 cross double light way forward scattering meter of Presentey E.Co.Ltd are midst and type MITRAS transmission meter of Vaisala Co.Ltd.is not so good at high visibility value.All of instruments gave quite good results when visibility value is below 2000 m.The measurement value of scattering meter is above mean when visibility value is over 4000m.Moreover,all instruments of examination meet the demands of meteorological indemnification of aviation when visibility value is below 4000m.