International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B3. Istanbul 2004 
  
topographic mapping in China we chose four modes for 
accuracy analysis, i.e. AT, DG, ISO without any GCP and ISO 
with 4 GCPs. Table 3 shows sample results of Mission A. Besides 
the obvious efficiency, our major findings are: 
® [SO with 4 GCPs delivered the best fit in comparison to AT 
results and was favorable. 
€ ISO without any GCP could even improve the results 
considerably. 
® DG had problems in vertical determination, but was still 
suitable for orthoprojection. 
The loss of orientation quality due to a long distance of a GPS 
base station to the mission area could be tolerable, especially in 
case of an ISO solution. 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
GPS base Mode Check > ; RM S (m) á : Max (m) s 
station points AX AY ADistance AZ ADistance AZ 
AT 31/15 0.091 0.067 0.113 0.078 0.236 0.124 
Anyangı DG 109 0.244 0.197 0.54 0.604 
ISO+0GCP 45 0.104 | 0.082 0.133 0.078 0.242 0.177 
ISO+4GCPs 41 0.115 0.089 0.146 0.078 0.255 0.152 
DG 109 0.291 0.191 0.475 0.659 
Beijing ISO+0GCP 45 0.149 | 0.221 0.267 0.116 0.412 0.374 
ISO+4GCPs 41 0.138 | 0.095 0.168 0.114 0.356 0.238 
  
  
  
  
  
  
Table 3. Sample results of the Anyang Mission A. 
3.3 Mission B 
Due to bad weather conditions in Anyang the planned Mission B 
(cf. Table 2) had to be postponed. The real flight was carried out 
on January 3, 2003, shortly before the first Chinese workshop on 
DGPS/IMU-based photogrammetry, held from January 11 to 13, 
2003, in Beijing. First experiences and results achieved from the 
Anyang project were presented and discussed on the workshop, 
signifying the real start of DGPS/IMU-based photogrammetry in 
China. 
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4. FURTHER PROJECTS 
In the following we just give an overview of DGPS/IMU projects 
conducted by the CASM team independently since the start work. 
4.1 Xingtai Project 
Xingtai Highway runs along the east-west direction, located about 
100 km north of Anyang. Another DGPS/IMU project was 
conducted there on December 29, 2002. The corridor flight 
covered a route length of about 251 km. The image scale was 
1:8,000. There were totally 14 strips or 368 photos taken. Figure 
I shows a part of trajectory of the flight. 
Figure 1. A part of trajectory of the Xingtai highway project. 
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