隨著數位化影像測量及電腦科技應用的發展與進步，LiDAR與數位量測相機技術的同軸結合可創造出有別於傳統地圖繪製的技術。本文探討直接地理對位( Direct Georeferencing ) 量測法結合數位量測相機技術於航空攝影測量的作業程序；並就實際施作成果檢討其精度。GPS、INS與數位量測相機同軸結合之誤差有二：（一）慣性導航系統與數位量測相機三維坐標軸線的夾角，即Boresight Angle angles的率定，Boresight Angle值的求定乃藉由比較空三解算程序所得到的影像外方位元素與由GPS/INS 直接提供的外方位元素的差異得到；（二）GPS、INS與數位量測相機三維坐標軸原點之間的距離（Level arm），此為機器安裝後固定的距離。
　　
　　本研究使用的設備為加拿大Optech ALTM 3070空載LiDAR及SN0048數位量測相機，而數位量測相機焦距 55.073 mm， CCD(Charge Couple Device) 陣列像元組成為4077 × 4092 pixel，像元大小為 9um（所以圖片大小為36.693 mm × 36.828 mm）。試驗場以大高雄地區為實驗範圍，其檢定場設置在高雄林園中油煉油廠，檢定場內規劃航線包括三條北／南向航線與三條東／西向航線，飛航高度約為1200 m，相片前後重疊約為60%，左右重疊約為30%，每一航帶8張相片，率定飛航範圍內包含兩個地面控制點。研究軟體採用Applanix公司之POSEO軟體，解算GPS/IMU導航定位之坐標後，加入挑選的CCD曝光時刻檔得到外方位元素。
　　
　　利用交叉航線的幾何特性，以Z/I Imaging公司的ISAT（ImageStation Automatic Triangulation）自動空三軟體進行自動連接點的匹配及空中三角測量平差計算，檢定場計算所得Boresight Angle率定值為：ω＝0.1653±0.002度；ψ＝-0.1186±0.002度；κ＝-0.6559±0.008度，其Boresight Angle 值套用在POS解算而得的外方位，應與空三求解的結果十分相近，藉此二種方式獲得的外方位元素應具有良好的一致性。空三所得之外方位元素與直接由GPS/INS所得值比較得標準偏差統計值，於投影中心平面位置縱橫坐標均為0.011m，高度為0.043m，數位量測相機旋角ω與φ均為0.002度，κ為0.008度。
　　
　　經由檢定場系統誤差改正後，試驗場由ISAT軟體進行空中三角平差，可得到偏差量最大值為（X0 ,Y0 ,Z0 ,Ω,φ,κ）max ＝（0.032,0.057,0.232,0.020,0.013,0.046 ）max，最小值為（X0 ,Y0 ,Z0 ,Ω,φ,κ）min ＝（-0.042,-0.048,-0.183,-0.016,-0.016,-0.050）min，均值為（X0 ,Y0 ,Z0 ,Ω,φ,κ）mean＝（0.000,-0.001, 0.000,0.000, 0.000, -0.001）mean，標準偏差為（X0 ,Y0 ,Z0 ,Ω,φ,κ）std ＝（0.018,-0.020,0.022, 0.001,0.001, 0.003）std ，且試驗場其最大值及最小值皆小於標準偏差三倍，因此其平差是改善完備的。標準偏差統計值，於投影中心平面位置X0坐標為0.018m、Y0坐標為0.020m、高程為0.022m，數位量測相機旋角ω與φ均為0.001度，κ為0.003度。
　　
　　所以LiDAR結合CCD的同軸空中測量，同步接收了IMU與GPS資料，省去一般需地面控制點來求得外方位元素的過程，僅需以檢定場飛行提供率定程序後，即可確保各張影像外方位元素的正確性，逕行產生正射影像。

　　As the development and progress of computer technology and digital image mapping, the integration of LiDAR with DC has created a new technology departing from traditional mapping. This paper discussed the procedure of applying direct georeferencing into aerial mapping using DC, in which the achievement of its precision is examined as well.
　　
　　There are two error sources when try to mount GPS, INS and CD with assuming the same axle : (1) The contained angle of INS and DC’s 3D coordinate axes that is the Boresight Angle angles. Boresight Angle values were obtained by calculating the difference of aerial triangulation Exterior Orientation (EO) and the EO directly provided by GPS/INS; (2) the distance between GPS , INS and DC, known as the Level arm is the regular distance after the install of those three devices.
　　
　　Equipments used in this research are Canadian Optech ALTM 3070, aerial LiDARs and SN0048 digital camera. The focus of the DC is 55.073 mms, CCD array picture element makes up for 4077 × 4092 pixels, the size of imagine pixel is 9um (so the size of the picture is 36.693 mm × 36.828 mm). The study area is Kaohsiung area and the calibration site is set at Chinese Petroleum Corp. LinYan Branch, associated with three north / south flight courses at the height of 1200m. It’s about 60% overlapping to the head to head photographs and about 30% to overlap from side to side, every boat is taken 8 photographs. There were two ground control points in each calibrating flight range. The adopted software is POSEO by Applanix to solve the calculation of GPS/IMU navigating coordinates, then, CCD images is selected to obtain EOP.
　　
　　Moreover, the utilization of geometry characteristics of crossing flight courses, ISAT automatically connected with match points to solve the adjustment aerial triangulation. The estimated Boresight Angle values of the calibration filed are: ω＝0.1653±0.002; ψ＝-0.1186±0.002; κ＝-0.6559±0.008. The result should be very close to the EOP obtained by applying the Boresight Angle value into POS. The difference of the EOP obtained by aerial triangulation and GPS/INS was small: both the horizontal and vertical abscissa of level position were 0.011m in the projection centre, 0.043m in the height and it was 0.002 degree that the camera fastens angle ω and ψ,κis 0.008 degrees.
　　
　　Via the fixation of the systematic error of the calibration field, the departure estimate of aerial triangulation for the calibration filed by ISAT can achieve a correction maximum（X0 ,Y0 ,Z0 ,ω,ψ,κ）max ＝（0.032,0.057,0.232, 0.020,0.013,0.046）max , the minimum is（X0 ,Y0 ,Z0 ,ω,ψ,κ）min ＝（-0.042,-0.048,-0.183,-0.016, -0.016 -0.050）min , mean value is （X0 ,Y0 ,Z0 ,ω,ψ,κ）mean＝（0.000, -0.001,0.000,0.000, 0.000, -0.001）mean , standard dev.（X0 ,Y0 ,Z0 ,Ω,φ,κ）std ＝（0.018,-0.020,0.022,0.001, 0.001, 0.003）std ,and its maximum and minimum of testing field are all smaller than three times of standard deviation, so its correction is improving completely. Standard deviation statistics value, level position X0 coordinate is 0.018m, Y0 coordinate is 0.020m, attitude is 0.022m in the projection centre, it is 0.001 degrees that the camera fastens angle ω and ψφ,κis 0.003 degrees
　　
　　It concludes that the integration of LiDAR with DC receiving IMU and GPS parameters is a step to avoid the need of control points on the ground.The calibration procedure applied to the calibration field is O.K. secure the accuracy of the EOP to generate orthophotography.

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