Advances in the Processing and Analysis of Photogrammetric 
and Remotely Sensed Data 
Prof Dr (Eng) habil Klaus Szangolies, President of ISPRS 
Commission II "Systems for Data Processing and Analysis" 
Dresden University of Technology 
Department of Surveying and Cartography 
Mommsenstrasse 13 
Dresden, DDR-8027 
1. Introduction 
The past ten years have seen a speedy progress of data 
extraction systems in photogrammetry and remote sensing, 
a development that has continued since the last ISPRS Congress 
in Kyoto in 1988 at an undiminished pace. 
We are aware that the main propelling forces for that 
development do not originate from our own field of activity 
but from the superordinate scientific disciplines of 
microelectronics/computer engineering, and 
space technology. 
The progress made there has a direct, only insignificantly 
delayed impact on the entire field of surveying and 
cartography. By estimation, about 30% of all data extraction 
assignments in photogrammetry and remote sensing will be 
carried out by means of computers, compared with only 20% in 1980. 
In other words, the use of optical and mechanical systems for 
photogrammetric compilation has substantially declined in terms 
of percentage. Universal stereoplotters such as the Stereo- 
metrograph, Topocart, Planimat, Aviomap, PG 3 and many others 
have been phased out of production. Although more than 10,000 
of these machines may still be in operation the world over, 
their function is successively taken over by analytical plotters 
and videomappers. The numbers of new instrument models of 
different makes introduced to the participants of the last 
three ISPRS Congresses developed as follows: