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PARTIAL FIELD CALIBRATION 
OF TWO RESEAU SYSTEMS OVER THE RHEIDT TEST AREA 
Guenther Kupfer 
Institute of Photogrammetry, University of Bonn 
Bonn, Fed. Rep. of Germany 
ABSTRACT 
A preliminary report dealing with the contribution of the Insti- 
tute of Photogrammetry of the University of Bonn and its Rheidt Test 
Area has been given at the XIIIth International Congress of Photo- 
grammetry in Helsinki. 
Since that time a certain amount of additional photographs of 
the experimental flights has been measured. Thus & representative 
number of imagery in both 1:11,000 and 1:5,500 photo scales is at 
hand for different types of partial field calibration. The NRC labo- 
ratory calibration data as supplied on March 2h, 1975, were applied 
throughout the whole computation up till now. 
Partial field calibrations centred on a "Standard Case" of four 
flight strips covering the test area crosswise at a photo scale of 
1:11,000. With and without application of lab. calibration and/or 
réseau information to image coordinates of object points, bundle ad- 
justments were performed with additional parameters of three different 
types. Computations without these parameters of field calibration 
proved at all stages to lead to less accurate results than with apply- 
ing them. Hence partial field calibration of photogrammetric systems 
may be recommended as & tool for enhancement of precision photogram- 
metry. 
A minimum of five fully controlled groups of three points is re- 
commended for the "Standard Case", & sufficient supply of additionally 
targeted points serving for definition of the whole photo geometry. 
Thus incorporating a test area within a flight mission becomes feas- 
able and economically attractive. 
Selected cases of variations of the "Standard Case" with diffe- 
rent photo scales, photogrammetric systems, and combined polynomials 
are giving improved results, which are also discussed. 
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