空載三線式掃描儀有較高的空間和光譜解析力，且影像具有良好之幾何交會條件，可為環境遙測、地理資訊系統及立體定位之資料來源。飛行中可拍攝三個方向影像，其成像具有高重疊的特性，使用光束法完成方位求解。在本研究中加入附加參數計算影像像坐標，外方位參數使用時間的多項式進行密合，以控制點和影像連結點完成方位計算，最後並使用最小二乘過濾法修正系統誤差。使用之資料為GPS/INS初步校正後之等級一(Level 1)影像。 研究中主要包含下列四項工作，(1)定義各影像之像坐標，利用附加參數計算不同觀測方向影像之像坐標，(2)光束法平差計算，利用地面控制點和影像連結點，給定不同的權，進行方位求解，(3)加入最小二乘過濾法進行系統性誤差修正，及(4)檢核成果，利用人工量測的影像連結點為檢核點，以空間前方交會檢核地面三維坐標之精密度。使用之測試資料共包含六個航帶，使用每一航帶之三張不同拍攝方向影像之影像連結點外，並加入航帶之間的航帶連結點進行光束法平差。實驗結果顯示以多航帶光束法求解方位，加入交叉飛行航帶後，可提升其整體精度，重疊區之精度亦可獲得提昇。 Airborne three-line-scanner images have the merits of high spatial and spectral resolutions and excellent converging geometry. Thus, the images have become an important data source in environmental remote sensing, GIS and three dimensional positioning. The three-line-scanner acquires three different direction images, which have plenty of overlapped area in flying. Thus, the bundle adjustment is selected to calculate the dynamic orientation parameters. The additional parameters will be included in the adjustment. The orientation parameters are modeled using low-order polynomials with respect to time by employing GCPs and tie points. The process might contain local systematic errors for the data with high dynamics, thus, a least squares filtering that performs orbit collocation is included. In this investigation, Level 1 images that have been preliminarily rectified using GPS and INS data are investigated for 3-D positioning. In this investigation four major steps are included: (1) definition of image coordinates for three-look images including additional parameters, (2) calculation of orientation parameters using bundle adjustment, (3) collocation of the orientation parameters by least squares filtering, and (4) accuracy validation. The test data include six trips. In bundle adjustment, the tie points are selected for each of the three-look images that appear in the overlapped area of strips. The experimental results indicate that the bundle adjustment could reach higher accuracy when the cross trips are employed.
