流星事件的研究為太空科學領域中的一個重要的議題。它不但可以增進人類對於來自外太空物體的科學知識，和流星與地球高層大氣交互作用的瞭解，同時對於利用流星尾進行越地平通訊(Over-the-Horizon Communication)應用以及高層大氣特性與動力的觀測與研究上，亦扮演著重要且關鍵的角色。在地面上，可以利用各種不同波段的雷達與光學照相設備進行流星事件的觀測與研究。在本計畫中，擬利用30MHz 與52MHz 雷達以及光學照相系統，進行流星事件的觀測，目的在瞭解雷達與光學照相系統所觀測到的流星事件的異同，同時研究由雷達所觀測到的流星尾回波所推算的中氣層溫度，與利用電波掩星法(Radio Occultation)所反演得的中氣層溫度的差異，進而推算出中氣層電子密度對於大氣折射指數的貢獻程度。本計畫為三年期的連續性計畫，預定執行期限為民國95 年8 月到98 年7 月。在本計畫第一年中，擬建立流星光學探測與定位系統，利用三座彼此分開適當距離的數位照相機所拍攝得的流星影像，根據背景星座，可以進行流星尾的定位。再利用地面特高頻雷達針對光學系統定位出的流星進行比對，以瞭解光學與特高頻雷達對於流星事件的觀測結果之異同。在第二年中，將利用特高頻雷達所觀測的流星尾回波，進行大氣溫度的估算，並與福衛三號電波掩星法所反演得的溫度進行比較，以瞭解二者的差異。第三年中，將利用雷達的流星尾回波所推算出的中氣層風場，配合人造衛星所量得的大氣溫度隨高度的變化，進行大氣重力波傳播的研究，藉此可以瞭解大氣能量藉由大氣重力波的垂直傳播所導致的高低層大氣的耦合作用。 Meteor event is one of the most important and critical issue in the field of space science. Its investigation can increase not only the knowledge of the human kind in the extra-terrestrial object entering in to terrestrial atmosphere, but also can apply to the over-the-horizon communication by using meteor trail and observation and investigation of the dynamics of upper atmosphere. The ground-based radar at various band and optical system have been used extensively to measure and investigate the meteor event. In this project, we plan to use 30 and 52 MHz radar and digital camera system with positioning capability located on the campus of National Central University (NCU) to detect meteor event for the purpose of understanding the difference between the characteristics of the meteor events detected by the radar and digital camera. In addition, the comparison of the mesospheric temperatures deduced from the meteor trail echoes observed by the ground-based radar and estimated by using the radio occultation technique made by GPS receiver on board the FORMOSAT-3 is made in this project to see the difference in the two. Through this comparison, the contribution of the mesospheric electron density to the mesospheric refractive index can be estimated. This project is a three-year long term project for the period from August 1st, 2006 to July 31, 2009. In the first year of the project, an optical detecting system of the meteor event is planning to establish on the campus of NCU, which is constructed by three sets of remotely separated digital camera system equipped with high resolution digital camera, data acquisition unit, GPS receiver, and tripod. With this system, the meteor event illuminated the visible light with a certain intensity can be detected and determine its location by using triangulation method with the help of the background stars. In the second year, the mesospheric temperature retrieved by the radio occultation technique made by the GPS payload of the FORMOSAT-3 will be used to compare with that estimated from the ground-based radar to see the difference in the two. In the third year, the mesospheric wind and wave events obtained from the drift of the meteor trail will be employed to deduce the gravity wave. Aside from the mesospheric wind variation, the temperature profile deduced from the radio occultation technique will be used to determine the wave propagation direction in horizontal. With this investigation, the plausible coupling between upper and lower atmosphere using the vertical propagation of the gravity wave can be explored and understood. 研究期間：9608 ~ 9707
