大氣混濁度不但是空氣污染的一個重要指標，也是影響遙測頻道的主要因素， 特別是可見光頻道。由大氣分子與氣溶膠的散射作用，遙測資料將無法直接提供地表真正 的訊息。但從另一個觀點而言，既然受散射的影響，則遙測資料將隱含大氣混濁度的資訊 。於是Tanre 等人於1988年提出一結構函數法以求取大氣氣溶膠的光學厚度。研究結果顯 示，在地表覆蓋物不變的前提下，利用多時的Landsat TM 資料可獲得氣溶膠的光學厚度 。由於臺灣地區的地形較為複雜，本研究將改進結構函數法並應用於SPOT及 GMS-5的衛星 資料，以估算臺灣地區大氣氣溶膠的光學厚度。研究結果顯示，經改進的結構函數法確有 較佳之準確度，且具極高的可行性。未來將可進一步地應用於空氣品質及污染的偵測。

　　　　　The atmospheric turbidity is one very important factor in the air pollution measurements and monitoring with remotely sensed data, especially in visible bands. The scattering effects of atmospheric molecular and aerosols in varying atmospheric turbidity conditions can influent the original spectral information of remotely sensed data strongly. From another point of view, the atmospheric turbidity can be estimated by evaluating the information variation induced by the scattering effects. Tanre, et al., proposed the Structure Function (SF) to estimate the atmospheric optical depth in 1988. Their study result showed that the Aerosol Optical Depth (AOD) can be assessed with Landsat TM data by assuming the landcovers are same in the set of multi- temporal TM images. In this study, the SF method is improved for applying in Taiwan area because of the rather rough terrain and complex landuse properties. Besides, the higher spatial resolution SPOT data and hourly GMS- 5 data were used to derive the AOD. The result shows the improvements in this study can get satisfying result, and it reveals we can derive these satellite data for the monitoring of hourly air pollution and air quality variation.