Photogrammetric on-line processing 
Dr. Ing. Werner Marckwardt, JENOPTIK JENA GmbH 
1. Introduction 
The comprehensive application of photogrammetry in metrolo- 
gical fields is placed on a new base by the extremely increas- 
ed importance of digital computer technology. Digital compu- 
tation takes over manifold tasks for the transformation and 
preparation of measurement results and for the accuracy 
increase by correction and adjustment techniques. The results 
are increasingly entered into data banks, which are accessed 
by users of photogrammetrically ascertained measurement and 
interpretation results. In this way an association with the 
results of other measurement procedures is simultaneously 
made possible (geodesy, navigation). The analogue computa- 
tion technique which was brought to perfection in the first 
half of our century and became the basis philosophy of photo- 
grammetry (photogrammetry as the "art of avoiding calcula- 
tions") has outside the national topography lost more and 
more in importance despite the character of & photo as an 
analogue image storage. 
At ihe beginning of this development the information trans- 
fer from the measuring instrument into the computer was 
accomplished with machine-readable data carriers as inter- 
mediate stores. The image or model coordinates were logged 
with special recording instruments (e.g. Coordimeter of 
JENOPTIK JENA GmbH, G.D.R.). The first direct (on-line) 
data transfer from a stereocomparator into a computer was 
devised in Jena by Dr. Otto Weibrecht in 1963 /1/. An equip- 
ment was created for the analytical point-by-point restitu- 
tion with the computation time amounting to less than one 
minute per point. 
In the following years photogrammetric engineers pursued the 
concept of on-line coupling of several machines with a larger 
central computer and an automatic drawing table. 
Then, miniaturization of the computers allowed the use of 
the microcomputer for data preprocessing and graphical 
representation, with the plotting machine being immediately 
coupled and a competitive situation arose between the de- 
central and central systems (Fig. 1). This stage must now 
be considered as finished. The possibilities of linking 
computer systems were developed to such a degree that 
optimum solutions are obtained without the use of data 
carriers for information transfer /2/ and "artificial in- 
telligence" is used in both central and decentral systems. 
The operator receives important information from the de- 
central microcomputer. The extremely great amount of collect- 
ed data additionally requires the use of a larger system for 
comprehensive transformation and adjustment celculations 
and for data filing and management. 
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