合成孔徑雷達影像使用微波獲取地表的資訊，因此具有全天候觀測和日夜皆可觀測的能力。為了提升雷達影像的應用，使校正過後的影像和其他地理資訊圖層的套合，並強化雷達影像在地理資訊系統的應用，雷達影像的幾何校正是必須的。傳統校正雷達衛星影像的做法是利用控制點，將雷達衛星軌道進行多項式平差。從直接地理對位的觀點出發，本文提出使用雷達影像反投影的方式進行雷達影像的校正，及簡化雷達影像的校正過程，並分析本研究方法的成效。由於有理函數模式標準化的處理流程，使得有理函數模式在光學影像上已經廣泛的使用，本研究也進行雷達影像有理函數模式的分析。 本研究的主要工作分成雷達影像反投影和雷達影像有理函數模式兩個部份。雷達影像反投影的工作項目分成建立雷達影像反投影程序、線性轉換、最小二配置和成果驗證。而雷達影像有理函數模式的工作項目分成建立有理函數模式、精化有理函數模式、最小二乘配置以及成果驗證。驗證部份測試不同的衛星資料並比較本研究提出的方法和PCI Geomatica Toutin模式進行成果的比較。成果顯示本研究提出的方法與PCI Geomatica Toutin模式相近或更佳。 Synthetic Aperture Radars (SARs) take the advantages of all-weather and day-and-night capabilities to detect object information in microwave bands. In order to enhance the applications of SAR data, the geometric correction is a must. Thus, the generated ortho-image can be registered with other GIS data layers. The traditional methods for the rectification of SAR imagery adjust orbit polynomials according to ground control points. From direct georeferencing point of view, this paper investigates the feasibility of Radar back projection and analyzes the accuracy of proposed method to simplify the processing for SAR imagery rectification at first. Owing to the implementation and standardization of Rational Function Model (RFM), it is widely used in the optical sensor adjusting. This research also investigates the feasibility of RFM for radar images positioning. The major works includeradar back projection and RFM. The proposed scheme for radar back projection includes (1) establishing the Radar back projection procedure, (2) linear transformation, and (3) least squares collocation. In addition, the proposed scheme for RFM includes (1) establishment of RFM (2) refining, and (3) least squares collocation. The experiments test the images for different satellites and, then, compare the proposed method with the PCI Geomatica Toutin’s model. The proposed method can reach similar or ever better result than PCI Geomatica Toutin’s model.
