i si 
+ : common feature points 
: computed still image position 
Figure 10. 3D model of First Flight 
  
  
t : common feature points 
-. t computed still image position 
Figure 11. Result of Second Flight 
  
i i A 
i: common feature points 
. : computed still image position 
Figure 12. 3D model of Second Flight 
From these experiments, it is confirmed that the proposed 
automatic corresponding point detection method and robust 
exterior orientation method have enough ability for automatic 
aerial triangulation using Low-cost UAV in low altitude 
photogrammetry. 
4. CONCLUSION 
In order to perform automatic aerial triangulation using Low- 
cost UAV in low altitude application field, we propose 
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B7, 2012 
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia 
automatic corresponding point detection method and robust 
exterior orientation method in this investigation. 
The automatic corresponding point detection method of this 
investigation utilize video image and still image. The video 
image can observe the movement of common feature points 
continuously by the robust common feature point tracking 
method based on OC image processing. Also, the LSM on still 
image gives fine accuracy image coordinate. Therefore, the 
automatic corresponding point detection method of this 
investigation gives many robust corresponding points from 
conventional features in each still image automatically. 
On the other hand, the proposed exterior orientation procedure 
using robust bundle adjustment base on M-estimator have 
ability to suppress outlier of GPS observation or miss matched 
corresponding points. Therefore, the exterior orientation 
parameter and 3D coordinate from this method is obtained in 
global coordinate system by using not accurate GPS and 
minimum global control points. 
However, the estimation of the reliability of proposed method is 
still not enough. Also, the process speed of proposed method 
has to be more increased. Moreover, in order to perform more 
accurate aerial triangulation without using global control points, 
utilization of RTK-GPS system has to be considered. Therefore, 
our next motivation will be the development of low altitude 
automatic aerial triangulation system using UAV that have 
RTK-GPS. 
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D, G, Lowe. 2004. Distinctive image features from scale- 
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