The Photogrammetric Research Section of the National Research Council of Canada is engaged in several 
research programs. Part of the NRC comprehensive program is concerned with the design and construction 
of analog and analytical photogrammetric instruments, systems and system components. The most recent 
work in this field has been devoted to the development of the NRC Analytical Stereorestitutor, a new 
universal analytical system on the level of present day technology, and to the extensions and impro- 
vements of instrumentation for generation and exploitation of orthophotos and stereo-orthophotos. As 
part of the international orthophoto experiment carried out by Working Group II - 4, ISP, the NRC 
analysed the height information obtained from ten different orthophoto systems, 
The Private mapping industry has played a key role in achieving the objectives of the mapping needs 
over the last four years, Today there are approximately 25 private companies engaged in the restitu- 
tion of aerial photographs. Almost all of these companies have supplemented their capabilities by 
adding one or more items of electronic equipment, These include automatic digitizers, on-line desk- 
top calculators, disk and tape drives, interactive terminals, display units and mini-computers. The 
instrumentation for restitution includes WILD STK1, A10, A7, A8 and B8, Kern PG2 and PG3, Zeiss 
Oberkochen Planimat, Zeiss Jena Stereometrograph and Topocart, OMI Nistri TA3/P, Gestalt Photo Mapper A 
Series I and II and many more. A new version of the analytical plotter has been developed by Instro- e L 
nics Ltd in cooperation with the National Research Council of Canada. In the restitution of aerial 
photographs for the production of orthophoto maps and photo maps, Gestalt Photo Mapper Series II, 
developed by Gestalt International Ltd., has achieved great success. In the fall of 1976, the Surveys 
and Mapping Branch will install the first of Gestalt Photomapper GPM-II. The Instrument was developed 
with the object of improving the precision and speed of the Gestalt Orthophoto Process. With this 
series, there is less restriction on scale and slope. It also provides digital terrain data for auto- 
matic contouring. Besides the GPM-I and II Series a number of other instruments such as Orthophoto, F 
SFOM Orthophographic Unit 693, Kelsh Orthophotoscope, Wild PPO-8 and Zeiss SEG V are also in use. 
The educational institutions in Canada provided a great deal of support by conducting studies related 7 
to the theory and methods of restitution of photographs. Three universities and several technological 1 
institutes are constantly carrying out research in the restitution of conventional aerial and terrestrial 
photographs as well as the restitution of imageries such as SLAR, Skylab and Landsat. In the process / 
of determining the possibility of modification and upgrading of analog plotters, a hybrid stereo res- 
titution system was developed, In another investigation, a method was developed at UNB for the recti- 
fication of infrared and radar imageries using the orthophoto printer OP/C attached to the analytical 
plotter. Another investigation at UNB lead to the study of relative orientation of continuous-strip 
imagery. 
RE dE»9 4 Pra Ae 
Canadian Forestry Service tested an Airborne Tilt-indicator, known as ADL-1, which can measure and ] 
record tilts at the instant of photographic exposure. Longitudinal tiit was measured to an accuracy 
of #0.3 degree 957 of the time which is satisfactory for the photogrammetric values typically used 
in large scale aerial photography in forest inventories. e - 
5 ad i fm. 
Activities in the field of restitution is continuing vigorously in all the photogrammetric institutions 
in Canada and the future looks quite encouraging. 
PUBLISHED WORKS 
l. Blachut, T.J., Van Wijk, M.C., "Results of the international orthophoto experiment 1972-76", 
Working Group II - 4, XIII Congress of the International Society of Photogrammetry, 
Helsinki, 1976, 
2. Crawley, B.G., "Gestalt Contours", Canadian Surveyor, Sept. 1976 p. 237 - 246. 
3. Derenyi, E., "SLAR Geometric Test', Photogrammetric Engineering, Vol. XL, No. 5, p. 597 - 604, 
May, 1974. 
4, Jaksic, Z., "Contemporary Trends in the design of photogrammetric instruments and systems", 
Proceedings of the first Pan-American Congress on Photogrammetry, Photo-interpre- 
tation and Geodesy, Vol, 1, Mexico City, 1974, 
5. Jaksic, Z., "Analytical Instruments in Close-Range Photogrammetry", Proceedings of the ASP, ISP 
Symposium on close-range photogrammetric systems, Champaign, Illinois, 1975, 
6. Jaksic, Z., "On-line Computational Photogrammetry in Surveying and Mapping", Proceedings of the e o.