The XII International Congress for Photogrammetry, held in Ottawa in 1972, 
passed thirty resolutions. Resolution 3 of Commission I read: 
"Commission I recommends the formulation of a Working Group on Image Geometry, 
with consideration for relevant liaison with the other commissions, particu- 
larly III, V and II. It is recommended, as a continuation of past efforts to 
calibrate individual components of the system, that one of the tasks of this 
working group be oriented toward the evaluation of calibration procedures for 
entire photogrammetric-data-acquisition systems. Another task to be considered 
would be metric experiments with side-looking radar." 
The result of this resolution was two working groups: the inter-commission 
working group on metric aspects and the Commission I working group on image geometry. 
In early 1973, Dr. H. Ziemann was asked to chair the group. He then asked Dr. D.C. 
Merchant, Professor at the Department of Geodetic Science of The Ohio State University 
in Columbus, Ohio, to be co-chairman. After some discussions, the two decided to take 
advantage of the availability of two réseau cameras of different types and organize a 
detailed study of camera calibration procedures by calibrating the same two cameras at 
various institutions. 
Further discussions with prospective participants in the project were carried 
out, primarily by mail, throughout 1973. The project started with photographic labora- 
tory calibrations in early March 1974, and had a bad start, because the Itek Artificial 
Stellar Calibrator was temporarily lost during its air cargo transfer from California to 
Ottawa. As a result, the plates eventually taken with this equipment had to be taken in 
a long 18 hour session with the result that exposure times could not be optimized for 
each exposure. 
After completion of the photographic laboratory calibrations in Ottawa, the 
cameras were shipped to Europe for calibration at the two manufacturers, Wild Heerbrugg 
and Zeiss Oberkochen, for photography over the Rheidt test field near Bonn, Germany, and 
over the Jämijärvi and Seglinge test fields in Finland, for visual calibration and modu- 
lation transfer function determination from photographed 3-bar targets at the Technical 
University in Helsinki, Finland, and for optical transfer function measurements at the 
Physikalisch-Technische Bundesanstalt in Braunschweig, Germany. Unexpectedly large 
delays in obtaining the Rheidt test field photography caused a reduction in the planned 
program both in Helsinki and Braunschweig. 
The cameras returned to Ottawa in August 1974 and were again calibrated and 
flown over the Sudbury test field. The cameras were then shipped to Washington, D.C., 
for stellar calibration at the National Ocean Survey and for photographic laboratory 
calibration at the Geological Survey, where again an unexpected delay was encountered. 
One camera was then, in January 1975, sent for aerial photography for a six-week period. 
After a delayed return, the cameras were forwarded to Duane Brown Associates in 
Melbourne, Florida, for stellar calibration. From there, they went to Dayton, Ohio, for 
modulation transfer function measurements. Finally, the cameras returned recently to 
Ottawa for another photographic laboratory calibration to conclude the project. 
With the exception of visual calibration, where measurements are obtained 
directly, the exposure of photographic records was only a first step. The following 
step - measurement of all the obtained photography - proved to be another major bottle- 
neck in some cases and caused further delays. At present most of the test field photo- 
graphy and all calibration plates taken under laboratory conditions have been measured. 
Not all participants in the project have as yet forwarded those data required 
for the preparation of the final report, although most have provided their standard 
calibration documentation. It is hoped that the outstanding data will be available in 
the near future. 
Comparison of all the different results is not an easy task, It will be carried 
out via lens distortion values for the reseau crosses. This will require extensive com- 
putational effort and was not helped by a 2-month unavailability of computational facili- 
ties earlier this year. 
The group met last October in Ottawa. This meeting had been scheduled to give 
all project participants a chance to present their results as well as to discuss the 
results of others. The delays in conducting the project, however, reduced the meeting 
to, in most cases, the presentation and discussion of preliminary results. 
The final report of each participant will be submitted for publication in 
Photogrammetria as they become available. The final working group report will be avail-