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ESTABLISHMENT OF A FEATURE DENSITY CLASSIFICATION SYSTEM 
H. G. Jerie and E. W. Holland 
I.T.C., Enschede, The Netherlands 
ABSTRACT 
The origins of the feature density classification system is closely 
linked to the OEEPE* cost modelling research task. Cost models are 
being developed, on one hand, in terms of production rates and, on the 
other hand, in terms of cost standards. While considering the factors 
which influence production rates, it is clear that the density of 
natural and cultural features on the ground is a very important factor 
affecting stereo plotting and cartographic rates. It is necessary to 
quantify the density of these features at the statistical analysis 
stage of the cost modelling task. The proposed feature density 
classification system is described in detail and the potential uses 
outlined. Feature density classification, as well as being an integral 
part of the cost modelling task, will also serve a much wider purpose 
by establishing standards which should assist individual organizations 
in making better estimates. Furthermore it is anticipated that the 
standards should be a useful reference in scientific publications and 
may find a use in contractual specifications. 
BACKGROUND 
Sound photogrammetrie planning requires detailed information about the 
economic aspects of technological alternatives. There is, however, very 
little published information on this subject and to rectify the 
situation the OEEPE created in 1978 a research group to investigate the 
establishment of 'cost models for photogrammetrie processes'. The prime 
objective of the research group is to study and report on 'how the 
increasing variety of techniques and instrumentation can be applied in 
the most rational and economic way'. The task is being undertaken by an 
international invited Working Group (WG) whose efforts are directed and 
coordinated by the ITC. After early interruptions active work started 
in 1981 and progress todate has been reported in an earlier paper to 
this symposium (Jerie and Holland 1982). 
In order that the results of the investigations shall be generally 
applicable in varying circumstances, it is proposed to develop the cost 
models as a function of, on one hand, cost standards and, on the other 
hand, production rates (Jerie, 1976). Production rates will be 
established for different sub-processes by statistically analysing 
production data supplied by the WG. It is well known that there are 
many factors which influence production rates. If we consider the 
environmental factors relevant to a particular project area, a major 
influencing factor for the stereo plotting and cartographic processing 
stages is clearly the density of the natural and cultural features 
being mapped. Our problem is to quantify the density of these features 
as they appear in different projects used in the statistical analysis. 
* European Organization for Experimental photogrammetric Research