微波降雨雷達(Micro Rain Radar，MRR)自 2005 年 6 月起架設於中國文化大學陽明山校區，由於
MRR 首度在位於副熱帶的臺灣觀測，其資料的品質與可信度對於往後在臺灣使用 MRR 觀測是相當重
要的評估依據。本文選取泰利、龍王颱風(2005)與 2006 年 2 月 25、28 日的層狀降雨系統個案，分別比
對在對流與層狀性降雨的環境之下，MRR 與中央氣象局五分山雷達、民航局桃園機場雷達、中國文化
大學撞擊式雨滴譜儀(J-W Distrometer，JWD)之觀測資料，藉此瞭解MRR的觀測資料與不同儀器之間的
差異程度與特性。結果顯示MRR垂直方向之雷達回波隨時間的變化與五分山跟桃園機場雷達觀測相當
一致，然而當五分山或桃園機場雷達回波大於45 dBZ時，MRR的雷達回波出現了低層資料缺少及高層
回波低估之情形。層狀降雨環境下，MRR 與其他兩個雷達的回波強度差異較小(~±3 dBZ)，分析 MRR
與 JWD 所觀測之雨滴粒徑分佈與降雨率資料，其小雨滴(< 1.5 mm)的數量相當接近且降雨率無顯著差
異。在颱風降雨環境中，MRR與其他兩個雷達的回波強度低估約6~18 dBZ，MRR小雨滴的數量則遠多
於 JWD 之觀測，大雨滴的數量則是少於 JWD，降雨率在雷達回波越強時，MRR 高估情形越顯著。因
此，在層狀降雨環境中，MRR、五分山與桃園機場雷達之雷達回波資料差異小，MRR 與 JWD 雨滴粒
徑分佈與降雨率資料有相當程度的一致性。在颱風劇烈對流環境中，MRR 之雷達回波、降雨率與雨滴
粒徑分佈中受電磁波衰減及儀器限制等因素影響存在著顯著的差異。

A vertical-pointing micro rain radar (MRR) was deployed at the campus of Chinese Culture University in
June 2005. Because this is the first opportunity for MRR to observe precipitation systems in the subtropical
region, to evaluate the reliability and quality of MRR observations collected in Taiwan is a critical task for
future application. With independent measurements taken from MRR, ground-based Doppler radars, and JWD
(J-W Disdrometer), this study performed intercomparison analyses of three observational parameters (radar
reflectivity, drop size distribution and rain rate) for these three instruments for some chosen typhoon and
stratiform rainfall events. Results indicate that MRR had temporal variations of radar reflectivity consistent
with those of ground-based Doppler radar. However, MRR tended to underestimate the reflectivity intensity at
higher levels when the radar reflectivity exceeded 45 dBZ. For stratiform rainfall events, all instruments had a
minor difference in radar reflectivity (~±3 dBZ), drop size distribution and rain rate. For typhoon rainfall
events, relatively weaker reflectivities were found for MRR, with approximate values of ~6-18 dBZ less than
those observed by the ground-based radars. The number of smaller rain drops (< 1.5 mm) as observed by
MRR was much greater than that of JWD, while larger rain drops were fewer for MRR. The MRR-derived
rain rates were obviously larger than those calculated from JWD when radar reflectivity became stronger.
These observational differences between MRR, JWD and ground-based radars depend mainly on the degree
of attenuation as well as the inherent limitation of the MRR instrument.