onstereomodelreconstitutioninaerialphotogrammetry-外文文献(编辑修改稿)

onstereomodelreconstitutioninaerialphotogrammetry-外文文献(编辑修改稿)内容摘要：

Frame /cmcm 2323 2323 2323 2323 Photographic scale 1:2 500 1:3 000 1:32 000 1:60 000 Forward overlap /％ 61 63 64 64 Side overlap /％ 32 33 33 30 Strip number 9 10 9 4 Control strips 2 2 2 0 Photos 255 377 244 48 GCPs 73 160 34 29 Densification points 3 631 5 442 2 951 712 Area /kmkm 45 58 4752 4057 Maximum terrain undulation /m (flat ground) (mountain) (high mountain) (lowland) GPS refresh rate /s 2 1 1 GPS initialize time /min 10 10 5 5 GPS static /min 5 5 5 5 GPS lever arm /m , , , , IMU lever arm /m , , , , , , Performance of exterior orientation elements In order to analyze the performance of exterior orientation elements obtained by different methods, standard AT with dense GCPs on the border and GPSsupported AT with four full GCPs in corners were firstly implemented, the six exterior orientation elements of each image can be obtianed, and their theoretic accuracy can be estimated. Then we assumed the results of standard AT as the “truth” and estimated the performance of exterior orientation elements provided by POS. The results are shown in Table 2. From Table 1, we see that the images of test 1, test 2 can be used for producing 4D product at the scale of 1:500~1:2 000, and images of test 4 for that at the scale of 1:5 000~1:10 000. In the principle of Topographic Maps Specifications for Aerophotogrammetric Office Operation[1113], test 1, test 2, test 3, and test 4 belong to flat land, mountain land, high mountain land, and lowland, respectively. From the results in YUAN Xiuxiao/On Stereo Model Reconstitution in Aerial … 239Table 2, some conclusions can be summed up as fol lows. Table 2 Accuracy of exterior orientation elements determined by different methods GCPs Check Pts RMS of check pts’ residual/m Theoretical accuracy of EO Images method σ0 /181。 m Hori. Verti. Hori Verti X Y XY Z Xs/m Ys/m Zs/m φ/(″) ω/(″) κ/(″)test 1 Std. 23 39 49 33 GPS 4 4 67 67 POS Std. 39 69 116 86 GPS 4 4 151 151 test 2 POS GPS 4 4 30 30 3 POS test 4 Std. 15 19 10 14 GPS 4 4 25 25 POS Note: 1) Std., GPS and POS stand that the exterior orientation elements are obtained by the method of standard AT with dense GCPs on the border,GPSsupported AT with 4 full GCPs on the corners and POS system, respectively (same to the following tables) . 2) Because the distribution of GCPs cannot meet the requirement of standard AT, for test 3 we cannot carry out the bundle block adjustment withdense GCPs on the border (same to the following tables). 3) RMS of check points’ residual is calculated from the error iΔ (i=X,Y,Z) between the adjusted coordinates and the ground measured coordinatesof n check points, that is 2iin181。 =Δ∑。 22, X YXY181。 181。 181。 =+. 4) Theoretical accuracy of EO is obtained from the unknown covariance matrix calculated according to the law of error propagation,0(,,)iiissmQXYZσ ϕ ωκ== . 1) For test 1, densified points’ horizontal accuracy and vertical accuracy are better than meter, totally meeting the accuracy requirement: meter in planimetry and meter in height[11] of 1:500 Topographic Maps Specifications for Aerophotogrammetric Office Operation for flat land. 2) For test 2, densified points’ horizontal accuracy is better than meter and vertical accuracy better than meter, totally meeting the accuracy requirement: meter in planimetry and meter in height[11] of 1:500 Topographic Maps Specifications for Aerophotogrammetric Office Operation for mountain land. 3) For test 3, densified points’ horizontal accuracy is better than meters and vertical accuracy better than meter, totally meeting the accuracy requirement: meters in planimetry and meters in height[12] of 1:5 000 Topographic Maps Specifications for Aerophotogrammetric Office Operation for mountain land. 4) For test 4, densified points’ horizontal accuracy is better than meters and vertical accuracy better than meters, totally meeting the accuracy requirement: meters in planimetry and meters in height[13] of 1:50000 Topographic Maps Specifications for Aerophotogrammetric Office Operation for high mountain land. It can be seen from Table 2 that for the images of different land types at different scales, the densified points obtained from standard AT and GPSsupport AT both satisfied the requirement of 4D product, and that the accuracy of exterior orientation elements obtained by these two methods are generally similar. The larger the photo scale is, the higher the accuracy of the photo’s linear elements we can get。 but the accuracy of the photo’s angular elements has nothing to do with the photo scale but is related to the focal length of the camera, so the shorter the focal length is, the higher the photo’s angular elements accuracy is. Additionally, by paring the data in Table 2, it can be found that the exterior orientation elements provided by POS system perform are worse than that of analytic aerotriangulation, and also obviously worse than the POS nominal accuracy ,XYZmmm=== 18 , 36mm mϕω κ′′ ′′== =.。