The Investigation of Precipitation in Front by VHF Radar

• Main Authors: Liang,Uei-Chung, 梁威中
• Other Authors: Chu,Yeh-Hsyang
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/82832988041688770523

碩士 === 國立中央大學 === 太空科學研究所 === 83 === MST雷達基本上是利用大氣折射指數的不均勻分布所產生的亂流散射及 取 回波。而在鋒面降水的天氣型態下，根據國內外學者的 此型雷達仍具備 優異的觀測能力。本論文所選用的資料為 蒝膉@天的降水資料。一般說來 ，大氣亂流訊號的頻寬對背 T應，至於在降水環境下，是否仍是如此？在 本篇論文將做 氻l訊號的頻寬對背景大氣以及其他降水參數是否有一定 關 中@併討論。另外本篇論文是第一個利用實際觀測的資料， k來驗證由 理論所導出之降雨粒子終端速度以及降水回波功率的關係。又在降水環境 下，大氣的結構變化也將在論文中簡單說明。 It is the first time using the observed MST radar echoes which was taken by Chung-Li VHF radar on Dec 25,1994 to experimentally prove the power-law relation between precipitation echo power,spectral width and terminal velocity by least square method.Examining the echo power difference between vertical and oblique beams shows that no aspect sensitivity is capable of observation,indicating that the atmospheric refractivity irregularities existed in the precipitation environment is isotropic,The results of fitting expermental function to the observed data shows implies the size distribution of can be described generally by exponential form,but not in the height of melting layer.Furthermore ,the beam broading effect on the turbulent and precipitation spectra is also examined.The results show that a good linear relation between turbulent width and horizontal wind speed is observed. However,the spectral width for precipitation is not affected by beam broading effect.