REPORT OF WORKING GROUP III/1 
ACCURACY ASPECTS OF COMBINED POINT DETERMINATION 
Heinrich Ebner*, Martien Molenaar**, Günter Strunz* 
* Technical University Munich 
Munich, F.R.G. 
Agricultural University Wageningen 
Wageningen, Netherlands 
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1. The XV. Congress of the International Society for Photogrammetry and 
Remote Sensing in Rio de Janeiro 1984 accepted Resolution III/4 
saying: : 
"The Congress noting that there is a great benefit in performing 
combined point determination using photogrammetric, geodetic, navi- 
gational and other data; and that an efficient quality assessment 
of the results is possible, recognizing that such procedures are of 
Based on this resolution the new Working Group III/1 with the name 
"Accuracy Aspects of Combined Point Determination” was established. 
Prof. Dr.-Ing. H. Ebner and Prof. Dr.Ir. M. Molenaar were appointed 
co-chairmen of the Working Group. Dipl.-Ing. G. Strunz became secre- 
tary. 
2. Working Group III/1 is dealing with the following topies: 
1. Formulation Of eriteria for the accuracy of the final 
results of combined point determination. 
2. Analysis of the accuracy of combined point determination 
by simulation of systems which are relevant in practice. 
3. Development of procedures to make planning and adjustment 
of combined point determination operational, 
re 1: Accuracy is understood as precision and reliability. 
Criteria for the precision of point coordinates and 
functions of these coordinates can be formulated using 
the theory of criterion matrices. A link should be 
made between this theory and practice. This means that 
criteria used in practice should be interpreted in terms 
of theory, or otherwise one should try to translate the 
theoretical concepts into parameters useful for the prac- 
titioner. The formulation of criteria for reliability of 
the final results is complicated by the fact that no cri- 
terion theory is available yet. 
re 2: Up till now separate simulations have been made to analyse 
the accuracy of photogrammetric blocks and geodetic net- 
works. The block simulations were based on simplified as- 
sumptions concerning the accuracy of control information. 
  
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