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International Archives of Photogrammetry and Remote Sensing, Vol. 32, Part 3W14, La Jolla, CA, 9-11 Nov. 1999 
4 SUMMARY 
Laser scanning is a novel approach for measuring surface 
elevations, from which digital surface models can be extracted 
easily and efficiently. However, laser measurements may suffer 
from systematic errors and from errors occurring near surface 
discontinuities. Integration of laser data with information 
available from aerial images is expected to render better surfaces. 
In order to integrate these two sources of information, they must 
be related to the same coordinate frame. A method developed for 
matching two surfaces and transforming one to the other has been 
presented. The method was tested both with synthetic and with 
real data and found stable and accurate. 
While testing the method, systematic differences between the two 
surfaces have been found. Future work should concentrate on 
analyzing the possible sources for these differences. Further 
work is also required in the area of analyzing surface 
characteristics for determining what transformation parameters 
can be calculated using the described algorithm. 
ACKNOWLEDGMENT 
This research project is partially supported by the United States- 
Israel Binational Science Foundation, research grant no. 97- 
00433. 
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