本計劃研究之重點主要針對ROCSAT-2衛星上所酬載具備全色態與多光譜兩種被動遙測感測器的遙測頻道建立大氣輻射校正之常規程序，並探討全色態及多光譜影像於不同觀測角度的輻射特性，去除因大氣效應影響在觀測影像上所造成之模糊效應，獲取正確的地表資訊，以提供地表覆蓋物之判識能力(分類)及多視角影像資料之鑲合等相關之應用，期能提昇ROCSAT-2衛星遙測資料之應用範圍與層次。一般在可見光波段中，大氣的效應主要來自於空氣分子和氣溶膠的削弱作用(extinction effect)，即吸收和散射效應，大氣散射的效應將會模糊地表的資訊，且這類效應的訂正並不容易，特別是來自於氣溶膠的散射效應。因此計劃目標除分析大氣中各吸收體含量在全色態及多光譜遙測頻道中輻射傳送之影響外，主要重點則在於利用衛星資料求取大氣氣溶膠光學參數研究方法之分析及探討，並建立ROCSAT-2衛星遙測頻道之大氣參數計算模式，以利ROCSAT-2衛星影像大氣輻射校正之使用。研究期間則將使用與ROCSAT-2衛星觀測頻道相似的SPOT系列衛星影像及IKONOS影像(NSPO提供)作為測試的資料。計劃中亦將應用前述之研究結果建立ROCSAT-2衛星遙測頻道之大氣輻射校正模式，及探討不同觀測角度對影像輻射特性之影響。期能獲得正規化(normalized)之輻射影像，以利多視角影像資料之鑲合與地表物變遷之偵測等相關應用研究。 This project's primary focus will be on ROCSAT-2's all color and multispectral passive sensors. Through the channels provided, there are four aspects we hope to achieve for ROCSAT-2G1) A regular procedure in the process of atmospheric radiation correction. 2) Understanding the different characteristics of all color and multispectral images under multi viewing angles. 3) Eliminating the blurring effect in images caused by atmospheric effects. 4) Obtaining accurate surface information where classifications can be made of the land cover, and constructing mosaic images from multi viewing angles. Ordinarily, in the visible bands, the atmospheric effect arises primarily from the extinction effects produced by air molecules or aerosols. The extinction effects refer either to the absorption or scattering effects produced by the particles. The influence of atmospheric scattering is most troublesome, because it obscures the data provided from the surface, and is not easily corrected, especially when they are caused by aerosol particles. Therefore, in this project, it will analyze the effects absorbing gases will have on the transfer of radiation in both all color and multispectral channels. But our primary focus will be on utilization of satellite data in the retrieval of the aerosol optical depth, and construction of a mathematical model in calculating the respective atmospheric parameters for ROCSAT-2. During the process, data obtained from channels similar to ROC-SAT-2 will be chosen from the SPOT and IKONOS satellite, where the data will be used to test the model.Besides, we will apply the results obtained from the project just described in constructing a radiation correction model for ROCSAT-2, and also to look into the influences different observation angles have on the measured radiation. It is hoped a normalized radiation image can be obtained, which may lead to relevant researches in image composites from various angles, or the detection of land cover changes. 研究期間：9105 ~ 9204
