本研究利用中央氣象局墾丁雷達之回波與風場資料，分析2003年杜鵑颱風路徑以及眼牆結構與演變。分析顯示，當杜鵑颱風進入墾丁雷達觀測範圍後，出現明顯的雙眼牆結構，且內眼中心路徑有明顯的週期性擺動現象，在觀測期間總共出現了四次擺盪，週期約3.0－4.0小時，振幅約10－15公里。此颱風內眼中心的擺動現象可能受到垂直風切的影響，而使得內眼牆偏移颱風中心，加上受到颱風環流導引下而導致逆時鐘的旋轉路徑，疊加大環境往西北方向的駛流後，產生了類似擺線的振盪路徑。分析結果也顯示，杜鵑颱風內眼中心擺動的現象導致其移動速度也呈現週期性的振盪，最大和最小的移動速度分別為14與4 m/s。此一擺動現象也使得最大徑向風場和路徑出現同相位的振盪，且遠離雷達和接近雷達方向之最大徑向風場的振盪呈現相反的相位關係，其最大風速差可達23 m/s。本研究針對杜鵑颱風此種擺盪路徑所導致風場的不對稱結構特徵的研究成果，將有助於增進未來類似路徑颱風之即時風雨分布的掌握。

The present study examines a prominent double eyewall case, namely, typhoon Dujuan (2003) as it neared the island of Taiwan. This typhoon was unusual in that its double eye was not concentric. It has been suggested that vertical wind shear caused the inner eye to drift away from the typhoon circulation center. Thus, the inner eye tended to circulate due to the steering of the rotational flow in the moat with a period of 3.5~4 h. The orbited inner eye motion superimposed on the typhoon motion as a whole resulted in a substantial oscillation, or wobble, and eventually manifested itself as a trochoid-like track.This study documents the phenomena of orbited inner eye which contributed to the oscillation of motion speed of the inner eye and the observed maximum inbound/outbound radial velocity in the vicinity of Taiwan. The maximum difference of velocity is up to 23 ms¯¹ between the oscillated maximum inbound/outbound radial velocity, and has been noted to be an important issue for nowcasting and hazard mitigations.