電離層斷層掃描網是運用在觀測臺灣以及東亞區域之電離層全電子含量、電子濃度與垂直變化的系統。臺灣自主電離層數值模式是一個全球電離層數值模式,可以提供從2007年至今全球電離層各層的峰值濃度、峰值高度以及標尺高。 應用電離層斷層掃描網系統與臺灣自主電離層數值模式之兩種資料,進一步蒐集2009年全年所有芮氏規模大於6的地震,再經過資料處理及分析後,我們觀察到在地震發生的前後幾天,電離層電子濃度會發生顯著的變化,在地震發生前震央上空區域會有電子濃度異常增加或減少的情形出現,根據這些物理特性資料,我們可進一步研究其是否可運用到地震預測上。A network of Ionosphere Tomography System(ITS) have been employed to derive the total electron content (TEC) and/or electron density of the ionosphere above Taiwan and the east Asia region. The TaiWan Ionospheric numerical Model (TWIM) is a numerical model of global ionospheric electron density ,which provides critical frequency , peak density height, and scale height globally for layers D , E , and F . In 2009, there are five earthquakes (M≧6.0) occurred in Taiwan. An analysis has revealed that the VTEC difference between ITS and TWIM data surrounding the epicenters of which events decreased or increased abnormally before the earthquakes.