外文翻譯----航空攝影測(cè)量中的立體模型重建（英文）

1、Geo-spatial Information Science 11(4): 235-242 Volume 11, Issue 4 DOI 10.1007/s11806-008-0099-03 December

2、2008 Article ID: 1009-5020(2008)04-235-08 Document code: A On Stereo Model Reconstitution in Aerial Photogrammetry YUAN Xiuxiao Abstract This paper describes the

3、operational issues and basic technical requirements of modern aerial photogrammetry. The accuracy of photogrammetric point determination and the y-parallax at corresponding model points is analyzed when stereo models are

4、 reconstituted by using the exterior orientation elements of aerial images. Real aerial photographs, at image scales from 1:2 500 to 1:6 0000, with DGPS/IMU data taken from various topographies in China were processed by

5、 our POS-supported bundle block adjustment program WuCAPS. The empirical results verified that the accuracy of the exterior orientation elements from bundle block adjustment meets the requirements of the specifications o

6、f topographic mapping. However, the accuracy of the exterior orientation elements determined by POS fails to meet the requirements of the specifica-tions of topographic mapping. Keywords aerial triangulation (AT); GPS (

7、global positioning system); POS (position and orientation system); stereo model re-constitution; ground control points (GCPs); accuracy CLC number P231.5 Introduction Aerial photogrammetry is the science and technol-ogy

8、 for obtaining 3-dimensional spatial information about the Earth’s surface from aerial images. Photo-grammetric point determination, which locates ground objects by using images, is the basis for ob-ject recognition in r

9、emote sensing. And the key point of this issue is the rapid and accurate determination of an image’s position and behavior at the instant of imaging. This goal was met by aerial triangulation based on well distributed GC

10、Ps. With the development of spatial positioning tech-nology, remote sensing technology, and computer science, aerial triangulation evolved and progressed towards digital mapping without GCPs. In the early 1950’s, photogr

11、ammetric scientists began studying how to utilize various auxiliary data to reduce the number of GCPs required. However, the methods haven’t become practical due to technological limita-tions[1]. Until 1970’s, with the e

12、mergence of Ameri-can Global Positioning System (GPS), people got to adopt carrier phase differential GPS (DGPS) tech-nology to determine an exposure station’s positions (that is three linear elements of aerial photos) d

13、uring aerial photographic process, which was used to per-form aerial triangulation (called GPS-supported AT for short) that can decrease photogrammetric reliance on GCPs, shorten the mapping cycle, and reduce Received on

14、 July 14, 2008. Supported by the National Natural Science Foundation of China (No. 40771176, 40721001), the Program for New Century Excellent Talents in Uni-versity (No. NCET-04-0662). YUAN Xiuxiao, School of Remote Sens

15、ing and Information Engineering, Wuhan University, 129 Luoyu Road,Wuhan 430079, China; State Key Labora-tory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, 129 Luoyu Road,Wuhan 430

16、079, China. E-mail：yxxqxhyw@public.wh.hb.cn DOI 10.1007/s11806-008-0099-3YUAN Xiuxiao/On Stereo Model Reconstitution in Aerial … 237shown in Fig.2. 2.2 Ground control plan In digital photogrammetry workstations, aerotri

17、-angulation is carried out by the most theoretically rigorous procedure of bundle block adjustment, but for the sake of obtaining the best pass points’ coordi-nates and the exterior orientation elements of photos, ground

18、 control plan should be designed, as shown in Fig.3, for different patterns of aerial photogrammetry.Fig.2 Patterns of the modern aerial photography Fig.3 Distribution of GCPs in bundle block adjustment2.3 Digital map

19、ping Theoretically, after getting the accurate exterior orientation elements of images, measurable stereo models can be reconstructed using model restoration, by which we can do surveying and mapping of terrain and objec

20、ts automatically. However, the current process of producing 4D product is: single photo in-terior orientation → relative orientation of stereo pair → single model absolute orientation → surveying and mapping on stereo mo

21、dels. The method of model restoration is only adopted in the direct georeferenc-ing of POS-supported aerial photogrammetry. 3 Experiments and analysis There are two ways of aerial photogrammetric po-sitioning. One is ca

22、lled block aerotriangulation, re-garding image points’ coordinates, GCPs’ coordinates and/or the exterior orientation elements of images as weighted observed values, and combined bundle block adjustment is performed to s

23、olve the images’ orientation parameters and target points’ spatial coor-dinates, so as to supply orientation control points for stereo model mapping and do highly accurate geo-metric positioning. For aerial photogrammetr

24、y of dif-ferent scales and topographic types, topographic maps specifications for aerophotogrammetric office operation has defined respective aerotriangulation method, ground control plan, and also concrete stan-dards fo

25、r pass point accuracy. This method is estab-lished and widely used. The other is called direct georeferencing, under the supposition that highly ac-curate image elements of exterior orientation were available, space inte

26、rsection is carried out to calculate corresponding object point’s object space coordinates by using photo coordinate system’s coordinates of conjugative image points in stereo pairs. This ap-proach directly determines th

27、e object’s position, so 4D products can be produced. Then the paper will mainly discuss how well the positioning accuracy can be achieved and the stereo model Y-parallax when using image exterior orientation elements obt