台灣地區劇烈天氣可大致分為颱風季節的強風和豪雨、梅雨季節的豪雨、鋒面附近中尺度對流系統，以及伴隨雷雨的冰雹、閃電等。氣象雷達是偵測與即時預報此類劇烈天氣最重要的工具，本計畫將以先進的雷達資料，包括偏極化雷達參數及都卜勒雷達參數，發展劇烈天氣預報技術。偏極化雷達可以觀測雨滴的粒徑分布、形狀及降水粒子的分類，採用偏極化雷達參數可以求出正確的降雨公式、降雨率，並且可以校驗氣象局雷達的回波降雨公式。由於中大雙偏極化雷達在2004年氣象局計畫支助下建置完成，從2005年參與北部降水觀測，因此延續2004年計畫目標，我們將繼續發展總合偏極化都卜勒雷達、雨滴譜儀網、雨量計網、ISS剖風儀，進行北部雷達資料先進品質改進，可以大幅改善氣象局雷達品質的問題。並繼續發展最佳降水的估計方法，提供雨量併入QPESUMS產品傳給水利署及氣象局。因此本計畫主要的目標為發展偏極化雷達硬體技術及軟體分析能力，從基本學理上改進中央氣象局目前雷達網連所使用的降水估計技術，建立雷達觀測資料的資料校驗系統，並做為未來氣象局全面發展偏極化雷達之前驅研究計畫。 Since 2002, the radar network of Central Weather Bureau has started its full operation. The major purpose of this project is to utilize the radar data to develop the useful algorithms and techniques for short range forecasting on severe weather, such as heavy rain during Typhoon and Mei-Yu, severe thunderstorms, etc. This project main purpose is to utilize the polarimetric/Doppler radar variables to improve the rainfall estimate and other severe weather phenomena such as hails and strong wind. In 2004 , the polarimetric upgrade of NCU polarimetric/Doppler radar has been finished in November. The rainfall estimate products from the radar observation will be sent to Central Weather Bureau and Water Resources Agency. The complex terrain also cause ground clutter and the blocking of radar beam energy, these factors also induce rainfall estimate errors. In the second year of this project, our work will be focused on the Polarization data quality control and data characteristics analysis. Radar optimization of the hardware and software will also be very important task for this year. The polarimetric variables observed by this new kind radar can provide drop size distribution, drop oblateness, and hydrometer types in a precipitation system. Because of the importance of polarimetric radar to the severe weather forecasting, this project will also be the risk reduction project for the future possible development of Central Weather Bureau radar application. 研究期間：9401 ~ 9412
