SPOT 5衛星影像兼具廣域性及高的空間解析力是資源衛星中最適宜作全國性的自然資源經營管理及天然災害監測者.本研究旨在建立SPOT 5影像之精密幾何校正方法以提升國內農林土地監測的能量.研究之重點包括 (1) 方位參數之重建及 (2) 影像反投影兩個部份.在方位參數重建部份將使用少量地面控制點建立方位處理之數學模式.其中因應恆星追蹤器所產生之Quaterion數學將予考慮.經軌道初步密合後,再實施最小二乘配置法予以精化.在影像反投影部份,則使用數值地形模型將任一地元之影像坐標完成計算,此時計算重點為成像時間之精密求定.待影像坐標求得後,灰值重新取樣並依逐點處理方式完成影像正射化.測試區將以台北及桃園地區之SPOT 5影像.控制點地面坐標將採執行單位所累積的資料庫.數值地形模型將採用農委會的數值地形模型,解析力為40 m.若近期內可得更佳的數值地形模型則將予以更替.測試之重點將包括精度及對控制點數量之需求。 Due to its high spatial resolution and wide sampling area, SPOT 5 imagery has the highest potential for nation-based natural resource management and hazard mitigation among various satellite images. The objective of this investigation is to develop a rigorous orthorectification system to improve the remote sensing capacity in agriculture and forestry monitoring. The proposed scheme comprises two major parts: (1) orientation modeling, and (2) image backprojection. In the orientation modeling, ground control points (GCPS) will be employed to establish the mathematics for orbit modeling. The geometry of quaternion, provided by the star tracker, will be considered. After the preliminary orbit filling, a least squares collocation technique is applied. In the image backprojection, digital terrain models are applied to determine the corresponding image pixel for a ground element. The essence of this calculation is the determination of sampling time. Once the image coordinates for a pixel in the raw image is determined, a resampling procedure is applied. The orthoimage is generated in the manner of pixel-by-pixel operation. The test site is in Taipei and Taoyuan area. GCPs will be selected from the GCP data base in NCU. Digital terrain models will be acquired from COA. The major test items include accuracy and the requirements of GCP quantity. 研究期間：9201 ~ 9212
